Mini-Proceedings ECT* Workshop Hadronic Atoms and Kaonic Nuclei - Solved Puzzles, Open Problems and Future Challenges in Theory and Experiment
aa r X i v : . [ nu c l - e x ] M a r Mini-ProceedingsECT* Workshop
Hadronic Atoms and Kaonic Nuclei
Eds. C. Curceanu (INFN-LNF/Frascati) and J. Marton (SMI/Vienna) ontents
The fascinating world of strangeness - introductory remarks
Catalina Curceanu, Johann Marton . . . . . . . . . . . . . . . . . . . . . . 3
Structure of K − pp and single-pole nature of Λ(1405)Y. Akaishi, T. Yamazaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The study of Λ π + , Λ π − , Λ γ , Λ p and Λ pp spectra from p+C interactionsat momentum of 10 GeV/c P.Zh.Aslanyan, V.N. Yemelyanenko . . . . . . . . . . . . . . . . . . . . . . 6¯ KN interactions at and near threshold A. Ciepl´y, J. Smejkal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Faddeev calculation of K − d scattering length J. Donoval, N.V. Shevchenko, A. Ciepl´y, J. Mareˇs . . . . . . . . . . . . . . 8
Investigation of the
Λ(1405) -resonance with HADES
E. Epple for the HADES collaboration . . . . . . . . . . . . . . . . . . . . 9
Future Experiments with Pion Beams at GSI
L. Fabbietti, HADES and FOPI Collaborations . . . . . . . . . . . . . . . 10
Quantum–classical calculations of cascade transitions in hadronic hy-drogen atoms
M.P. Faifman, L.I. Men’shikov . . . . . . . . . . . . . . . . . . . . . . . . . 11
Round table discussion: critical summary on reported BKS observa-tions
A. Filipp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Many facets of the kaonic atoms ‘puzzle’
E. Friedman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Multi- ¯ K (hyper)nuclei D. Gazda, E. Friedman, A. Gal, J. Mareˇs . . . . . . . . . . . . . . . . . . . 14
HadronPhysics2 and beyond
C. Guaraldo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
The Search for a K − pp Bound State with FOPI O.N. Hartmann on behalf of the FOPI Collaboration . . . . . . . . . . . . 16
Kaonic He X-ray measurement with SIDDHARTA
T. Ishiwatari et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Molecule model for kaonic nuclear cluster ¯ KN N
M. Faber, A. N. Ivanov, P. Kienle, J. Marton, M. Pitschmann . . . . . . . 18
Analysis of cascade dynamics and x-ray yields for K − p and K − d atomsby Monte-Carlo method S.Z. Kalantari and M. Raeisi G. . . . . . . . . . . . . . . . . . . . . . . . . 19
Search for Double Antikaon Production in Nuclei by Stopped An-tiproton Annihilation
Paul Kienle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 ypernuclear production in ( K − stop , π ) reactions V. Krejˇciˇr´ık, A. Ciepl´y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
The in-flight C ( K − , p ) reaction at KEK V.K. Magas, J. Yamagata-Sekihara, S. Hirenzaki, E. Oset, and A. Ramos . 22
Kaonic nuclei
J. Mareˇs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
LEANNIS: a liason between theory and experiment in antikaon physics
J. Marton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Recent results on K − absorption at rest on few nucleon systems withFINUDA S. Piano . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
SIDDHARTA recent results
A. Romero Vidal on behalf of the SIDDHARTA Collaboration . . . . . . . 26
QGP formation in antiproton annihilation at rest
P. Salvini, G. Bendiscioli, T. Bressani . . . . . . . . . . . . . . . . . . . . . 27
The trigger system for the AMADEUS experiment
A.Scordo, et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Two- and three-body resonances in the ¯ KN N − π Σ N system N.V. Shevchenko . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
The investigation of
Λ(1405) state in the stopped K − reaction on deu-terium T. Suzuki, J. Esmaili, and Y. Akaishi . . . . . . . . . . . . . . . . . . . . . 30
Analysis of the K − He interactions in the KLOE drift chamber
O. Vazquez Doce on behalf of the AMADEUS Collaboration . . . . . . . . 31 Antikaon Interactions with Nucleons and Nuclei
W. Weise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Extraction of the KN subthreshold amplitudes from K − atoms S. Wycech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Experimental confirmation of the
Λ(1405)
Ansatz from resonant for-mation of a K − p quasi-bound state in K − absorption by d , Heand He Toshimitsu Yamazaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Indication of a strongly bound dense K − pp state formed in the pp → p Λ K + reaction at 2.85 GeV T. Yamazaki, M. Maggiora, P. Kienle, K. Suzuki on behalf of the DISTOcollaboration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
The AMADEUS project – precision studies of the low-energy an-tikaon nucleus/nucleon interaction
J. Zmeskal for the AMADEUS Collaboration . . . . . . . . . . . . . . . . 37 List of Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Conference Photos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 he fascinating world of strangeness - introductoryremarks
Catalina Curceanu , Johann Marton LNF-INFN. Frascati (Roma), Italy SMI-Vienna, Austria
Experts and young researchers in strangeness hadronic and nuclear physics from all overthe world participated in the International Workshop “Hadronic atoms and nuclei - solvedpuzzles, open problems and future challenges in theory and experiment” held from 12 to16 October, 2009 at the European Center for Theoretical Studies in Nuclear Physics andrelated areas, ECT*, at Trento, Italy.What is an hadronic atom and why there is growing interest in their study?An exotic hadronic atom is formed whenever a hadron (pion, kaon, antiproton) from abeam enters a target, is stopped inside and replaces an orbiting electron. Such an exoticatom is usually formed in a highly excited state; a process of de-excitation through therespective atomic levels then follows. The X-ray transitions to the lowest orbits (1 s ) are af-fected by the presence of the strong interaction between the nucleus and the hadron, whichis translated into a shift of the 1 s level with respect to the purely electromagnetic-basedcalculated value and by a limited lifetime (width) of the level. Extracting these quanti-ties, via the measurement of the X-ray transitions, provides fundamental information onthe low-energy hadron-hadron and hadron-nuclear interactions, impossible to obtain byother methods. Quantities such as kaon-nucleon scattering lengths turn out to be directlyaccessible by measuring the properties of exotic atoms. Furthermore, these quantities areimportant milestones to deal - in a unique way - with important aspects of the low-energyQCD in the strangeness sector, such as the chiral symmetry breaking. Although the fieldof exotic atoms has a long history, it lives presently a second youth (renaissance), bothfrom the experimental and from the theoretical point of view. On the experimental side,new “hadronic” beams became available recently (kaons at DAΦNE) or will become avail-able in 2010 (J-PARC facility), while new detectors, with improved performance (betterenergy resolution, stability, efficiency, trigger capability,) are starting to operate. On thetheoretical side the field has advanced significantly through recent developments in chiraleffective field theories and their applications to hadron-nuclear systems.The kaonic hydrogen was measured by the DEAR Collaboration (on DAΦNE) with anunprecedented precision, leading to a lively debate on the kaon-proton scattering lengthextraction procedure, and on the compatibility with existent kaon-nucleon scattering data.The SIDDHARTA experiment is performing in 2009 an even more precise measurementand will complement it with an exploratory measurement of the kaonic deuterium; theresults were presented and discussed at the Workshop. Kaonic helium was measured atKEK (E570 experiment) and SIDDHARTA - solving the “kaonic helium puzzle”, whilenew experiments are planned at J-PARC in the near future (E17) to measure X-rayspectrum of kaonic- He at highest precision. Other experiments are already planned atexistent and/or future machines (GSI, J-PARC, DAΦNE). The future of exotic hadronicatoms will reach new horizons - in precision and in dealing with new types of exotic atoms,never measured before, such as kaonic deuterium, or sigmonic atoms.Another hot item intensively discussed at the Workshop deals with the recently studied“Kbar -mediated bound nuclear systems”. It was originally suggested that in the few-body3uclear systems the (strongly attractive) isospin I = 0 ¯ KN interaction can favour the for-mation of discrete and narrow barK -nuclear bound states with large binding energy (100MeV or even more). Recent theoretical works suggest, however, that such deeply boundkaonic nuclear states do not exist: antikaon-nuclear systems might only weakly bound andvery short-lived. Different interpretations for the existing experimental results are given,based for example on the interaction of negative kaons with two or more nucleons. Thistopic is related to a new puzzle in the physics of kaon-nucleon interaction: the nature ofthe Λ(1405) - single or double pole structure? Long discussions were dedicated to thisitem in the Workshop. All these topics have important consequences in astrophysics aswell - in the physics of the neutron stars for example.The presently available experimental results were reviewed (KEK experiments. FINUDAat DAΦNE, FOPI, BNL, OBELIX, Dubna experiments, DISTO at Saturne), togetherwith a critical discussion of current theories/models. Future perspectives at J-PARC (E15,E17); GSI (upgrade of FOPI and HADES) and DAΦNE (AMADEUS experiment), to-gether with the possibility to use antiprotons to create single and double strangeness nuclei(CERN, J-PARC or FLAIR) were discussed in the framework of an integrated strategyin which complementary facilities should bring together the various pieces of the puzzle.The field of Hadronic atoms and kaonic nuclei is a very active one, as was fully provenduring this Workshop. There are indeed solved puzzles , as kaonic hydrogen and kaonichelium ones - which were understood, both due to the newer experiments (E570 andDEAR and SIDDHARTA at DAΦNE) and to theoretical interpretation, but many openproblems are still present. Important questions were targeted and formulated, but they stillneed both experimental results and deeper theoretical understanding.
So future challengesin experimental and theoretical sectors are many and were, for the first time, focussed andformulated in a unitary framework.Last but not least, is to be underlined the strong participation of young researchers, whowere more than 50% of participants.We decided to collect in the form of present mini-proceedings short (1-page) contributionsfrom participants, in order to leave a testimony of the status of the field by the end of2009, since we are convinced progress will be quick and rather dramatic in the comingyears.Full details of this workshop can be found at tructure of K − pp and single-pole nature of Λ(1405)
Y. Akaishi , , T. Yamazaki , RIKEN Nishina Center, Wako, Saitama 351-0198, Japan College of Science and Technology, Nihon University, Funabashi, Chiba 274-8501, Japan Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
We have predicted few-body deeply bound kaonic states [1,2], starting from the Ansatzthat Λ(1405) is a K − p quasi-bound state, Λ ∗ , of single pole. The structure of K − pp reveals a molecular feature, namely, the K − in Λ ∗ as an “atomic center” plays a keyrole in producing strong covalent bonding with the other proton [3]. Thus, it is proposedthat strongly bound ¯ K nuclear systems are formed by “super-strong” nuclear force dueto migrating real boson, ¯ K .Figure 1 shows that the Λ(1405) is of single-pole nature in spite of the claim of adouble-pole structure based on chiral SU(3) dynamics [4]. The experimental evidence forthe two-pole structure of Λ(1405) [5] is logically impossible to stand, since the 2nd polecannot produce any peak structure in the relevant mass region. It is urgently importantto distinguish the Λ ∗ mass, 1405 or 1420 MeV/ c . A bubble-chamber Σ π invariant-massdata from stopped K − on He supports the Λ(1405) Ansatz [6]. A stopped K − on D experiment [7] would provide a decisive datum for the mass discrimination. UGUGUUU -+= Σπ ;2 NK;1 nd polepeak X M Sp [MeV/ c ] case opt22 U case U HemingwayZychor et al. M Sp [MeV/ c ] (a) (b) UGUGUUU -+= Σπ ;2 NK;1 UGUGUUU -+= Σπ ;2 NK;1 Σπ ;2 NK;1 nd polepeak X M Sp [MeV/ c ] case opt22 U case U HemingwayZychor et al. M Sp [MeV/ c ] (a) (b) Figure 1: Σ π invariant-mass spectrum by two-channel treatment of chiral SU(3) dynamics.(a) When the coupling to ¯ KN is reduced, the peak goes to disappear at the 1st poleposition. (b) The spectrum is compared with experimental data: a large discrepancy isseen above the ¯ K + N threshold. References [1] Y. Akaishi and T. Yamazaki, Phys. Rev. C (2002) 044005.[2] T. Yamazaki and Y. Akaishi, Phys. Lett. B (2002) 70.[3] T. Yamazaki and Y. Akaishi, Proc. Jpn. Acad. B (2007) 144.[4] T. Hyodo and W. Weise, Phys. Rev. C (2008) 035204.[5] V.K. Magas, E. Oset and A. Ramos, Phys. Rev. Lett. (2005) 052301.[6] J. Esmaili, Y. Akaishi and T. Yamazaki, arXiv: 0906.0505v1, 0909.2573v1 [nucl-th].[7] T. Suzuki et al. , this Workshop. 5 he study of Λ π + , Λ π − , Λ γ , Λ p and Λ pp spectra fromp+C interactions at momentum of 10 GeV/c. P.Zh.Aslanyan, V.N. Yemelyanenko Joint Institute for Nuclear Research, LHEP
The observed well-known resonances Σ , Σ ∗ + (1385) and K ∗± (892) [1-3] from PDG aregood tests for this method. Exotic strange multibaryon states have been observed in theeffective mass spectra of: Λ π + , Λ π − (Fig.1), Λ γ (Fig.2), Λ p (Fig.3) and Λ pp subsystems[1-3]. Fig.3 has shown Λ p spectrum in momentum range of 0.14 < P p < c for 4669 combinations from primary p+C interactions. There are signifi-cant enhancements in the mass regions of 2090(4.6 σ ), 2144(6.2 σ ), 2215(4.3 σ ) and smallenhancements in maas regions 2290,There are new small enhancements for total Λp spec-trum[3] ( from primary and secondary protons interactions)in mass range of 2900, 3070and 3210 MeV/ c , when applied geometrical weights of Λ. The enhancement productionfor all registered hyperons than calculated geometrical cross sections are observed [1-3].The mass of exited Σ ∗− (1385) is shifted to M(1370) which interpreted as contributionfrom low momentum π − [1](Fig.1). The mean value of mass for Σ ∗ + (1385) from secondaryinteractions is also shifted in mass range of 1370 MeV/ c too[3]. The width of Σ ∗− (1370)two time larger in medium of carbon than PDG data. Such kind of behavior for width ofΣ ∗− (1385) resonance is interpreted as the sum of contributions from stopped Ξ − → Λ π − ,Σ ∗− (1385) and reflection from Λ ∗ (1405) resonances. The width of Σ is ≈ γ [3](Fig.2). It can interpret as reflection of interactions from Λ and Σ hyperons in mediumof carbon nucleus. The reflection from Ξ , Σ ∗ (1385), Λ ∗ (1420) hyperons in (Λ γ ) spectrumwith total geometrical weights are observed. (1370) *- S ‹ M(1480) ‹ - Xfl a) S ‹ X ‹ (1385) S fl (1420) S ‹ b) <0.3 GeV/c p ‹ ‹ c)Figure 1: a)The Λ π − - spectrum for all combinations with a bin size of 11 MeV/ c ; b)theΛ γ spectrum with total geometrical weight and bin size 10 MeV/ c ; c)the Λ p spectrumwith stopped protons in the momentum range of 0.14 < P p < c from primaryprotons with bin size 12 MeV/ c ;. The dashed curve is the experimental background fittedby polynomial function. The dashed histogram is the simulated events by FRITIOF. References [1]P.Z. Aslanyan, Physics of Particles and Nuclei, Vol. 40, No. 4, pp. 525 557, 2009.[2]P.Z. Aslanyan, Proc. IUTP’09, Schladming, Austria, 29-6 March, 2009.[3]P.Zh.Aslanyan, Proc. Int. Conf., Windows on the Universe, 16-21 June, Blois, 2009.6
K N interactions at and near threshold , J. Smejkal Nuclear Physics Institute, 250 68 ˇReˇz, Czech Republic Czech Technical University, Horsk´a 3a/22, 128 00 Praha 2, Czech Republic
We have constructed effective separable meson-baryon potentials to match the equivalentchiral amplitudes up to the second order in external meson momenta. The potentials wereused in the standard coupled channel Lippman-Schwinger equations to compute the lowenergy K − p cross sections and branching ratios from the resulting transition amplitudes.At the same time the potential was also used to solve the K − -proton bound state problem.This way the characteristics of the 1s level in kaonic hydrogen are obtained by directcalculation, not by relating them to the K − p scattering length by means of the Deser-Trueman formula. A direct calculation of the kaonic hydrogen characteristics is essentialin view of the expected precision of the current K -atomic SIDDHARTA experiments onhydrogen and deuterium.The model parameters were fitted to the three precisely measured threshold branchingratios γ , R c and R n , the low energy K − p cross sections, the DEAR data on kaonic hydrogenatom and to the peak position of the π Σ mass spectrum. In the Table 1 we show theresults of our fits for four different choices of the pion-nucleon sigma term σ πN . Thestrong interaction energy shift ∆ E N of the 1s level in kaonic hydrogen is reproduced wellbut we were not able to get a satisfactory fit of the 1s level decay width Γ as our resultsare significantly larger than the experimental value.Table 1: The fitted ¯ KN threshold data σ πN [MeV] χ /N ∆ E N [eV] Γ [eV] γ R c R n
20 1.33 214 718 2.368 0.653 0.18930 1.29 260 692 2.366 0.655 0.18840 1.35 195 763 2.370 0.654 0.19150 1.37 289 664 2.366 0.658 0.192experiment - 193(43) 249(150) 2.36(4) 0.664(11) 0.189(15)The ¯ KN dynamics at low energies is strongly affected by the Λ(1405) resonance ob-served in the π Σ mass spectrum, just below the ¯ KN threshold. The coupled channelmeson-baryon models based on chiral symmetry generate the resonance dynamically andit appears that there are two poles in the complex energy plane that may contribute to itsspectrum. In our model, the position of one pole is more or less stable and does not de-pend much on the choice of the parameter set. Its complex energy z ≈ (1400 − i 45) MeVcan clearly be associated with the observed π Σ mass spectrum. The second pole is lo-cated further from the real axis and its position vary with the chosen parameter set. It isintriguing that neither of the poles is so close to the real axis as other authors claim.More details on our work including a discussion of the K − n elastic scattering amplitudeare given in Ref. [1]. References [1] A. Ciepl´y and J. Smejkal, to appear in Eur. Phys. J. A , arXiv:0910.1822 [nucl-th] The work was supported by Grant Agency of the Czech Republic, grant 202/09/1441. addeev calculation of K − d scattering length J. Donoval , N.V. Shevchenko , A. Ciepl´y , J. Mareˇs Nuclear Physics Institute, 250 68 ˇReˇz, Czech Republic
Plausible values of the scattering lengths of K − d and K − p systems are essential forextracting the K − n scattering length, better understanding of low-energy ¯ KN interactionand extrapolating into ¯ K -nuclear systems.The K − d scattering length was calculated within the Faddeev equations in the AGSform [1]. Dealing with scattering at low-energies, we work in s-wave approximation andwe neglect relativistic corrections. For simplicity, we assume that the isospin symmetry isnot broken. Our calculations are performed in the momentum and isospin basis.For the N N interaction, we have considered the PEST potential [2] and the energy de-pendent potential by Garcilazo [3], which we have modified according to more recentexperimental data. We have used two separable ¯ KN potentials. The first one is our ownphenomenological potential with the Yamaguchi formfactors. The parameters of the po-tential were determined from the K − p scattering lengths [4,5] and the properties of theΛ(1405) resonance, which is usually assumed a ¯ KN quasibound state and a resonancein the π Σ channel. The second one is the chirally motivated potential [6]. The effectivechiral model was based on the s-wave meson-baryon lagrangian up to the second orderand reduced to an equivalent single-channel complex potential for our purposes.Table 2: The K − d scattering length calculated using various two-body inputs (in fm).PEST E-dep N N phenomenological ¯ KN − .
51 + i 0 . − .
46 + i 0 . KN (KEK fit) − .
78 + i 1 . − .
62 + i 1 . KN (DEAR fit) − .
66 + i 1 . − .
53 + i 1 . I = 0 ¯ KN interaction, which is much stronger, is more im-portant for the K − d system than I = 1 ¯ KN interaction. Moreover, the chirally based po-tentials give much higher imaginary part of a K − d than the phenomenological one (see Ta-ble 1). By using the Deser-type formula in next-to-leading order in isospin breaking wehave calculated the kaonic deuterium level shift ǫ d and width Γ d . The phenomenolog-ical potential gives ǫ d phen . ≃
730 eV , Γ d phen . ≃
470 eV, while the chiral potentials lead to ǫ d chiral ≃ , Γ d chiral ≃
890 eV.This work was supported by the GA AVCR grant KJB100480801 and the GACR grant202/09/1441.
References [1] E.O.Alt, P.Grassberger, W.Sandhas, Nucl. Phys. B2 (1967) 167.[2] H.Zankel, W.Plessas, J.Haidenbauer, Phys. Rev. C28 (1983) 538.[3] H.Garcilazo, Lett. Nuovo Cimento (1980) 73.[4] T.M.Ito et al. , Phys. Rev. C58 (1998) 2366.[5] G.Beer et al. , Phys. Rev. Lett. (2005) 212302.[6] A.Ciepl´y, J.Smejkal, arxiv.org/abs/0910.1822v1.8 nvestigation of the Λ(1405) -resonance with HADES
E. Epple for the HADES collaboration Excellence Cluster Universe, TU-Munich, Germany
Although the Λ(1405) resonance has been investigated since several decades there is stilla lack of high statistic and quality data to verify the broad spectra of theories that havebeen developed on that field. Data, extracted from kaon- and pion- induced reactionshave been made available in the past [1,2]. Recently also data from p+p reactions havebeen published, which show the decay of Λ(1405) → Σ π [3]. We have also measuredp+p at 3.5 GeV with the HADES spectrometer at GSI and attempted to reconstruct theΛ(1405) line shape out of its decays in the (Σ π ) channels. In p+p reactions the Λ(1405)is produced together with a proton and a kaon, so that it can be reconstructed via themissing mass technique. The analysis however has to deal with the fact that a nearbyresonance the Σ(1385) , that is produced in the same way like the Λ(1405), is close inmass and broad, so that a separation in the analysis has to be done by the identificationof their decay products. This however is only possible in the following decay, where adifference in the missing mass of p, K + , p, π − for the both resonances can be found:Λ(1405) → Σ π → (Λ γ ) π → ( pπ − ) γπ (1)Σ(1385) → Λ π → ( pπ − ) π (2)The other decays of the Λ(1405) are equal to the ones of the Σ(1385) , so that thecontribution of the Σ(1385) in the Λ(1405) missing mass spectrum has to be subtracted.Fig. 1 shows the background subtracted missing mass spectra of the Σ π (left) andthe Σ ± π ∓ decay of the Λ(1405) (right). The contamination of the Σ(1385) , which wasestimated via simulations and found to be in the order of 15 % was not subtracted yet.Furthermore the spectra are not efficiency and acceptance corrected.Figure 1: Left: ∆ M p,K + for the Σ π decay channel. Right: ∆ M p,K + for the two chargeddecay channels of the Λ(1405) (Σ + π − and Σ − π + ) both only with statistical errors. References [1] R. J. Hemingway et al. , Nucl. Physics
B253 (1985) 742-752.[2] D. W. Thomas, A. Engler et al. , Nucl. Physics
B65 (1973) 15-45.[3] I. Zychor et al. , Phys. Lett.
B660 (2008) 167-171.9 uture Experiments with Pion Beams at GSI
L. Fabbietti HADES and FOPI Collaborations. Excellence Cluster ”Universe”, Technische Universit¨at M¨unchen
Pion beam with momenta varying from 1.0 to 1.7 GeV/c can be accelerated at the SIS18facility at GSI Darmstadt and they can be exploited for fixed target experiments. As aresult of the development carried out in the last years, currently secondary pion beams,with a maximal intensities of 10 and 10 particle per second for a beam momentum of 1.3GeV/c can be delivered to the FOPI and HADES detector respectively. These two spec-trometer can be exploited to perform complementary studies on the hadron properties in π − + A/π − + p reactions. The FOPI spectrometer, with its high geometrical acceptancefor charged and neutral hadrons, can be exploited to study the production of φ mesons onnuclei and their decay into K + K − pairs. Indeed, strangeness production in pion-inducedreactions is well suited to study the kaon absorption in normal nuclear matter density.Comparing the production rates in π − + p and π − + A absorption measurement for the φ meson for different A values the strength of the interaction between the K − and thenucleus can be determined [1]. On the other hand, in order to disentangle the intrinsicproperties of the φ meson in the nucleus from the K − behavior, exclusive analysis can becarried out to tag the K − not coming from the φ decay.If we consider the K − nuclear potential U KA , it consists of one part connected to theK − -p scattering length and to a part dependent on the K − absorption in the nucleus. TheK − scattering length is known from kaonic atom experiments [2], while not very muchis known on the absorption potential. The planned measurement should provide a validcontribution to determine the imaginary part of this potential.Similar measurements can be accomplished with the HADES spectrometer, with the dif-ference that the geometrical acceptance is optimized for the mid-rapidity region and doesnot provide the full phase-space coverage. On the other hand the performance of the dataacquisition system (DAQ) of the HADES Spectrometer is a factor 30 higher than themaximal rate achieved with FOPI. On the other hand, HADES can deliver a very precisemeasurement of the dilepton decay of vector mesons ( ρ, ω ) produced in the nucleus.Since the ω and ρ change their properties inside the nuclear matter, it is of interest tostudy how many of them decay inside the nucleus. According to simulations results, atthe incident energy of 1.17GeV about 65% of ω ’s and 90% of ρ ’s decay inside the nucleus.The modifications of the meson self-energy in the nucleus [3] can hence be studied.Since the secondary pion beams are delivered with a momentum spread of about 8%, accu-rate and radiation-hard devices are necessary to track the beam particles event by event.Currently, we are working on the development of large area mono-crystallin diamonds [4]which are suited devices for our tracking purposes. References [1] Ye. S. Golubeva, L.A. Kondratyuk and W. Cassing, Nucl. Phys. A 625 (1997) 832.[2] B. Borasoy et al. Phys. Rev. Lett. 94 (2005) 213401; M. Cargnelli et al. Int. J. Mod.Phys. A 20 (2005) 341.[3] M. Urban et al., Nucl. Phys. A 641 (1998).[4] J. Pietraszko et al., im Press in NIMA, arXiv/nucl-ex:0911.0337.10 uantum–classical calculations of cascade transitionsin hadronic hydrogen atoms
M.P. Faifman, L.I. Men’shikov
Russian Research Center “Kurchatov Institute”, 123182, Moscow, Russia
The interpretation of experimental data and planning the high precision measurements [1]of the X-ray yields in the kaonic hydrogen pK − and deuterium dK − require an additionaltheoretical study of cascade processes in such atoms.The attempts to create a universal code based on pure quantum mechanical calculatingthe cascade characteristics encounter the problem of the lack of a complete set of thecollision de-excitation cross-sections (see [2,3] and references therein). This reason hasdetermined our choice to develop a quantum–classical calculating method of a purelyclassical description of the exotic atom collision with the hydrogen atom, whereas Augerprocesses are considered in a semi-classical way, and radiative transitions are describedwithin the framework of quantum mechanics. Such “a compromise” provides a way for abinitio calculation of the physical cascade characteristics with an accuracy of ∼ pK − and dK − atoms have been calculated atdifferent hydrogen target densities (Fig.1). a) KK K , density Y , ( % ) pK - exp. [5] K [2] dK - b) KK Y , y i e l d ( % ) , density K Figure 1: The K α , K β and K γ -yields in kaonic atoms as function of density reduced tothe liquid hydrogen density. a) The yields for pK − atoms calculated with the nuclearcapture width in the 2 p -state Γ p =2 meV [4]; b) The dK − atom yields for the nuclearcapture width Γ p =4 meV [2].Our calculating scheme allows to obtain as well the other basic cascade characteristicswhich are needed for the detailed analysis of the DEAR/SIDDHARTA experimental data. References [1] C. Curceanu et al., Eur. Phys. Journal
A31 , 537 (2007); Hyp. Int. (2009) 11.[2]M.P. Faifman et al., Frascati Phys. Series
XVI (1999) 637.[3] M. Raeisi G., S. Z. Kalantari, Phys. Rev.
A79 (2009) 012510.[4] M.P. Faifman, L.I. Men’shikov, Hyp. Int. (2009) 141.[5] T.M. Ito et al, Phys. Rev.
C58 (1998) 2366.11 ound table discussion:critical summary on reported BKS observations
A. Filippi INFN Torino, via P. Giuria, 1, 10125 Torino, Italy
It might be useful to point out at possible similarities of possible Bound Kaonic Systems(BKS) observations reported at this Workshop and performed in different experimentalenvironments, as a start for a thorough understanding of a few disagreements among someof them.
E549 vs FINUDA . Outa [1] reported the results of a missing mass analysis of the K − He → Λ pX reaction in the E549 experiment. The central component observed in the (Λ p ) in-variant mass spectrum, peaked around 2230 MeV/ c , could be tentatively explained asdue to the contribution of the two-body absorption in Σ N , or due to the non-mesonicdecay of a BKS. Piano [2] showed the FINUDA (Λ p ) invariant mass spectrum for K − Lievents. By means of the missing mass technique the contributions from Q.F. Λ p and Σ p two-nucleon absorption could be separated: the latter could explain just a small part of theobserved bump, centered at 2255 MeV/ c . Moreover, this signal could not be explainedby Σ N conversion reactions, as the expected signature for such channels did not complyto the observed strong Λ p back-to-back angular correlation. After a proper acceptancecorrection the positions of the peak observed by E549 and by FINUDA agree, within theexperimental errors. FINUDA vs OBELIX . The missing mass spectrum of the K − Li → Λ pX shown by Piano[2] exhibits a sharp peak in correspondence to the opening of the K − Li → Λ π , ± p N reaction threshold. This signal shows up as a narrow peak in the (Λ p ) invariant massspectrum at about 2200 MeV/ c . The appearance of sharp peaks at reaction thresholdsis a well known kinematic (“cusp”) effect and had been observed several times right atthis value since the early bubble chamber experiments [3]. A signal in the same invariantmass region and approximately the same width was observed by OBELIX [4] in the ( ppπ − )invariant mass spectrum, in the analysis of the ¯ p He → ( pπ − ) pK S X annihilation reaction.For this structure both the interpretation of BKS or of threshold effect can in principlebe suggested. FOPI vs early K − d observations . Herrmann reported the observations by FOPI of the (Λ p )invariant mass spectrum obtained in Ni+Ni and Al+Al collisions [5]: they observed, inindependent analyses, a peak at 2135 MeV/ c , a lower value as compared to the FINUDApeak. This mass value is however in good agreement with the observations by old bubblechamber experiments of K − d → Λ pπ − X [6-7]: the signal was indicated to be due to a cuspeffect related to the opening of the Σ nπ − channel, rather than to a new resonance. Alsoin this case an alternative interpretation of the recently observed signal can be suggested. References [1] E549 Experiment, H. Outa, talk given at this Workshop [2] FINUDA Experiment, S. Piano, talk given at this Workshop [3] T. Buran et al. , Nucl. Phys. Phys. Lett. (1966), 318[4] G. Bendiscioli et al. , Nucl. Phys.
A789 (2007), 222;
Eur. Phys. Jour.
A40 (2009), 11[5] FOPI Experiment, N. Hermann, talk given at this Workshop [6] D. Cline et al. , Phys. Rev. Lett. (1968), 1452[7] D. Eastwood et al. , Phys. Rev. D3 (1971), 260312 any facets of the kaonic atoms ‘puzzle’ E. Friedman
Racah Institute of Physics, Hebrew University, Jerusalem
The expression ‘kaonic atoms puzzle’ refers to an apparent conflict between phenomeno-logical optical potentials obtained from fits to kaonic atom data and the correspond-ing potentials constructed from more fundamental approaches [1,2]. Whereas the best-fitphenomenological potentials have for the real part typical depths of 180 MeV at nuclear-matter densities, the corresponding depth of chiral-motivated potentials [3] is 30-40 MeV.The χ values are 85 for 65 data points for the former as opposed to χ of 260 for thelatter. The question of how sensitive kaonic atom observables are to the nuclear densitywas discussed recently in terms of a functional derivative approach [4]. It was shown thatkaonic atom data are sensitive to the surface region of nuclei up to almost the full nucleardensity. Similar analysis of antiprotonic atoms show [2] that the sensitivity is only atthe extreme surface region where the density is ∼
5% of the central values. Indeed onecan estimate a mean-free-path of a particle in nuclear matter as λ = 1 /ρσ , with ρ thedensity and σ the total cross section for particle-nucleon interaction. Then λ ∼ K − mesons, λ ∼ p .We have analyzed the LEAR data [5] on the elastic scattering of 300 and of 600 MeV/cantiprotons by several nuclei. We find these data to be well described by a potential verysimilar to the global antiproton-nucleus potential of ref.[6] with typical χ per point of2.2 - 2.5. The potential uses a finite-range ¯ p -N interaction with rms radius of 1.4 fm anda fairly constant real part of an effective scattering amplitude of 0.6 fm. The imaginarypart varies between 1.25 fm for atoms to 1.8 fm at 600 MeV/c. To clearly demonstratethe extreme peripheral nature of the ¯ p -nucleus interaction, we have repeated all the fitswith a potential proportional to the radial derivative of the nuclear density. Equally goodfits are obtained for the atoms as well as for scattering, where the potentials essentiallyvanish in the interior when using the derivative form. The non-penetration of the ¯ p is thusclearly demonstrated.Returning to kaonic atoms, we have performed, in parallel to antiprotonic atoms, similarfits based on the derivative of the nuclear density, but acceptable fits could not be achievedover very broad range of parameter values. It thus demonstrates again, in addition to thefunctional-derivative analysis[4], that kaonic atom data are sensitive to the nuclear densityand the deep potentials which yield the best fit between experiment and calculation verylikely are a reliable representation of the K − -nucleus interaction at close to the full nucleardensity. References [1]E. Friedman, A. Gal and C.J. Batty, Nucl. Phys. A (1994) 518.[2]E. Friedman and A. Gal, Phys. Reports , (2007) 89.[3]A. Ramos and E. Oset, Nucl. Phys. A (2000) 481.[4]N. Barnea and E. Friedman, Phys. Rev. C (2007) 022202(R).[5]S. Janouin, Saclay report CEA-N-2453 (1985).[6]E. Friedman, A. Gal and J. Mareˇs, Nucl. Phys. A (2005) 283.13 ulti- ¯ K (hyper)nuclei D. Gazda , E. Friedman , A. Gal , J. Mareˇs Nuclear Physics Institute, 25068 ˇReˇz, Czech Republic Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
In this contribution we report on relativistic mean-field (RMF) calculations of baryonicsystems containing several antikaons. We focus on the question whether or not kaoncondensation could occur in strong interaction self-bound nuclear matter, thus whetherthe K − mesons could be the relevant degrees of freedom of self-bound strange matter, assuggested recently in Ref. [1]. This scenario requires that ¯ K separation energy exceeds k B K - ( M e V ) O+8 L+ K -40 Ca+20
L+2X +k K -90 Zr+40
L+2X +2X - +k K -208 Pb+106 L +2 X +18X - +k K - Figure 1: The K − binding energy as a func-tion of the number κ of antikaons in severalhypernuclear configurations. the threshold value of roughly m K + µ N − m Λ ≈
320 MeV, thus allowing for the con-version Λ → ¯ KN in matter. We followed theobservation of Refs. [2, 3], where the bindingenergy of K − mesons, as well as the associ-ated nuclear and K − density distributions,were found to saturate upon increasing thenumber of the K − mesons embedded in thenuclear medium. The saturation pattern wasfound to be a robust feature of these multi-strange configurations. It is present acrossthe entire periodic table, independent of theRMF model used, and occurs for any meanfield composition containing the dominant ω -meson exchange. In Ref. [4], we generalizedour calculations into the hypernuclear do-main and studied whether the presence of hy-perons could alter our previous conclusions.In Fig. 1 we present the 1 s K − binding en-ergies B K − as a function of the number κ of antikaons bound in several particle-stablehypernuclear systems. These configurationswere built on top of selected core nuclei byadding first the Λ and then Ξ hyperons until both conversions ΛΛ ↔ Ξ N were kinemati-cally forbidden, thus the resulting system being particle-stable against strong interactions(for details see Ref. [4]). It is to be stressed that in all cases the B K − does not exceed120 MeV in these multistrange configurations, which is considerably short of the thresh-old value of ≈
320 MeV necessary for the onset of kaon condensation under laboratoryconditions.This work was supproted in part by GACR grant 202/09/1441 and by SPHERE withinthe FP7 research grant system.
References [1] T. Yamazaki, A. Dot´e, Y. Akaishi, Phys. Lett. B 587, (2004) 167.[2] D. Gazda, E. Friedman, A. Gal, J. Mareˇs, Phys. Rev. C 76 (2007) 055204.[3] D. Gazda, E. Friedman, A. Gal, J. Mareˇs, Phys. Rev. C 77 (2008) 045206.[4] D. Gazda, E. Friedman, A. Gal, J. Mareˇs, Phys. Rev. C 80 (2009) 035205.14 adronPhysics2 and beyond
C. Guaraldo INFN, Laboratori Nazionali di Frascati, CP 13, Via E. Fermi 40, I-00044, Frascati(Roma), ItalyHadronPhysics2 is an Integrating Activity within the Seventh Framework Programme of EU ( FP7 ) • The ProjectCoordinator: INFN (Italy) Project Coordinator: C. Guaraldo (LNF-INFN)Other involved institutions: 104 OrganizationsTotal involved researchers: 2500 from 36 countriesEuropean Commission budget: 10 million euro Duration: 30 months • Project structure:8 Networking Activities, 5 Transnational Access Activities, 14 Joint Research Ac-tivities, Management of the Consortium – Networking Activities: 2 theoretical (QCD, TORIC), 3 experimental (PrimeNet,FAIRnet, ReteQuarkonii), 2 in the strangeness sector (SPHERE, LEANNIS),1 on the structure of the nucleon (TMDnet) – Transnational Access Activities: 3 with hadronic probes (FZJ-COSY, GSI,INFN-LNF), 1 with e.m. probes (UMainz-MAMI), 1 for theoretical studies(FBK-ECT*) – Joint Research Activities : 10 on detectors R& D (CARAT, FPCC, FutureGas,DIRCs, SCiFi, HardEx, JointGEM, ULISI, JETCAL, SiPM), 2 on polarization(SPINMAP, PolAntiP), 1 on target development (FutureJet), 1 on lattice cal-culations (LatticeQCD) • Participation to the project – Composition of the Consortium per country:Germany: 18 organizations; United Kingdom: 4 organizations; France, Poland,Spain: 3 organizations; Austria, Czech Republic, Italy, Sweden, The Nether-lands: 2 organizations – Leaderships of activities per organization:INFN: 6; GSI:4; FZJ, UGlasgow, CNRS: 2 – Leaderships of activities per country:Germany: 14; Italy: 7; Austria, France, United Kingdom: 2 • Beyond HadronPhysics2The strategy of the Commission to optimize the budget remaining in FP7 for Inte-grating Activities (about 350 Meuro) consists in a targeted approach with selectedtopics, covering both projects funded in the past and new classes of the projects. TheCommission foresees to fund around 40 projects (up to of a maximum 10 Meuro)and to public around 80 topics in 3 Calls: 40 for potential follow-up projects, 40 fornew projects. HadronPhysics2 is among the follow up projects invited to the Call8, to be published in July 2010, for an eventual HadronPhysics3.15 he Search for a K − pp Bound State with FOPI. O.N. Hartmann on behalf of the FOPI Collaboration Stefan-Meyer-Institut f¨ur Subatomare Physik der ¨OAW, Vienna, Austria
The existence of bound states among antikaons and nucleons, with large binding energiesand small widths, has been predicted by T. Yamazaki and Y. Akaishi in [1]. In [2], the sameauthors propose to exploit proton-proton collisions to produce the simplest K − -nucleonbound state K − pp in the reactionp + p → K − pp + K + . (1)where a Λ ∗ acts as a doorway state which together with another proton can form thebound state.Furthermore, the maximal predicted cross section for reaction (1) suggests a proton beamenergy around 3 GeV [2]. A K − pp could decay like (2).K − pp → Λ + p . (2)Making use of the Λ → π − + p decay, an experimental approach for the identification ofa K − pp is to compute the invariant mass of Λ + p (2) and the K + missing mass (1) fromthe charged final state particles.An appropriate experiment had been proposed and has been accomplished in summer2009 with the FOPI detector at the SIS accelerator of the GSI [3,4]. FOPI provides thenecessary acceptance for the mentioned final state particles.The detector setup was extended by a new segmented plastic scintillator as start detector,capable to deal with high beam rates, a liquid hydrogen target system with an upstreamveto counter, and a trigger for Λ hyperons. The latter one is designed to allow for anonline comparison of the multiplicity of charged particles. The bulk part of produced Λhyperons decay in between two layers of silicon strip detectors, hence the second layersees more charges than the first one. The thresholds can be set hardwarewise. Employingthis trigger, the non-strange background events can be suppressed significantly (approx.by a factor 10).The second layer of the silicon detector provides a spatial information in ( x, y ), too. This isused to improve the vertex reconstruction capability with tracks under small polar angles.The liquid hydrogen target, a target cell with a kapton entrance and exit window, filledwith liquid hydrogen, was placed in the vacuum of the beam pipe.The new start detector delivered a time of flight resolution of ≈
130 ps (for one strip; q.v.[5] for details on FOPI’s T.O.F. detectors).The beamtime at the GSI took place in august and september 2009. In total 80 MEventswhich fulfill the Λ trigger condition were recorded. Currently, the data are being calibrated.From the first preliminary analysis a number of several 10 reconstructed Λ hyperons inthe forward hemisphere has been estimated. The invariant mass spectra of (p, π − ) and theK + missing mass spectra show the expected behaviour as seen in the simulation. References [1] Y. Akaishi and T. Yamazaki, Phys.Rev.C (2002) 044005[2] Y. Akaishi and T. Yamazaki, Phys.Rev.C (2009) 312c[5] N. Herrmann, Contribution to this Workshop16 aonic He X-ray measurement with SIDDHARTA
T. Ishiwatari , M. Bazzi , G. Beer L. Bombelli , A.M. Bragadireanu , M. Cargnelli G. Corradi , C. Curceanu (Petrascu) , A. d’Uffizi , C. Fiorini , T. Frizzi , F. Ghio ,B. Girolami , C. Guaraldo , R.S. Hayano , M. Iliescu , , M. Iwasaki , P. Kienle , ,P. Levi Sandri , A. Longoni , V. Lucherini , J. Marton , S. Okada , D. Pietreanu ,T. Ponta , A. Rizzo , A. Romero Vidal , A. Scordo , H. Shi , D.L. Sirghi , , F. Sirghi , ,H. Tatsuno , A. Tudorache , V. Tudorache , O. Vazquez Doce , E. Widmann ,J. Zmeskal Stefan-Meyer-Institut f¨ur subatomare Physik, Vienna, Austria INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy Dep. of Phys. and Astro., Univ. of Victoria, Victoria B.C., Canada Politechno di Milano, Sez. di Elettronica, Milano, Italy IFIN-HH, Magurele, Bucharest, Romania INFN Sez. di Roma I and Inst. Superiore di Sanita, Roma, Italy Univ. of Tokyo, Tokyo, Japan RIKEN, The Inst. of Phys. and Chem. Research, Saitama, Japan Tech. Univ. M¨unchen, Physik Dep., Garching, Germany
The SIDDHARTA experiment measured the kaonic He 3 d → p X-ray transition in agaseous target, where Compton scattering in helium is negligible. The kaonic atom X-rays were detected with large-area Silicon Drift Detectors using the timing informationof the K + K − pairs produced by φ decays at the DAΦNE e + e − collider. A new valueof the strong interaction shift of the kaonic helium-4 2 p state was determined to be0 ± ± − ± ∼ Energy [keV]Ti K α Ti K β Mn K α Mn K β KHe L α Energy shift of the kaonic helium 2 p state∆ E p (eV) Ref. − ±
33 Wiegand et al. [3] − ±
12 Batty et al. [3] − ±
12 Baird et al. [3] − ± ± ± et al. [2]0 ± ± He X-rays
References [1] M. Bazzi, et al. , (SIDDHARTA Collaboration), Phys. Lett. B 681 (2009) 310.[2] S. Okada, et al. , Phys. Lett. B 653 (2007) 387.[3] C. J. Batty, Nucl. Phys. A 508 (1990) 89c, and refrences therein.17 olecule model for kaonic nuclear cluster ¯ K N N
M. Faber , A. N. Ivanov , P. Kienle , , J. Marton , M. Pitschmann Atominstitut der ¨Osterreichischen Universit¨aten, Technische Universit¨at Wien,Wiedner Hauptstrasse 8-10, A-1040 Wien, Austria Stefan Meyer Institut f¨ur subatomare Physik ¨Osterreichische Akademie der Wissen-schaften, Boltzmanngasse 3, A-1090, Wien, Austria Excellence Cluster Universe Technische Universit¨at M¨unchen, D-85748 Garching,Germany
The kaonic nuclear cluster (KNC) ¯
KN N (or K H) with quantum numbers I ( J π ) = (0 − )and the structure N ⊗ ( ¯ KN ) I =0 has been predicted by Akaishi and Yamazaki [1] in anon–relativistic potential model approach with the binding energy B K H = 48 MeV andthe width Γ ( π ) K H = 61 MeV, caused by the pionic K H → p Σ π decay modes only. Accordingto [1], the simplest KNC is the isospin–singlet state ( ¯ KN ) I =0 (or K H), identified with theΛ(1405) hyperon with quantum numbers I ( J π ) = 0( − ) and mass M Λ ∗ = 1405 Mev. Wepropose to treat the KNCs n ¯ K H, where n > K H is equal to zero, theproperties of this state are determined by the vibrational degrees of freedom only, which wedescribe by trial harmonic oscillator wave functions. Such a choice can be justified by theshort–range character of forces producing quasi–bound KNCs [1,2]. The later allows alsoto describe the properties of the KNC K H, treated as an antikaonic ( ¯ KN ) I =0 atom in theground state, by a harmonic oscillator wave function. In our model the binding energiesand widths of KNCs n ¯ K H are defined by the real and imaginary parts of the diagonalmatrix elements h n ¯ K H | T | n ¯ K H i of the T – matrix [2]. This agrees with the definition of thebinding energies and the widths of strongly coupled nuclear systems within the opticalpotential approach. The matrix elements of the T – matrix are calculated in the heavybaryon approximation, using chiral Lagrangians with derivative meson–baryon couplingsinvariant under chiral SU (3) × SU (3) symmetry, which are used in Chiral Perturbationtheory (ChPT) and SU (3) coupled–channels technique for the analysis of low–energystrong interactions. This allows to calculate both non–pionic and pionic decay modes ofthe KNC K H, expressed in terms of two input parameters Ω Λ ∗ , the frequency of the ¯ KN oscillations in the KNC K H, and g Λ ∗ , the coupling constant defining the strength of theΣ π decay modes of the KNC K H. With the assumption that the mass of the KNC K Hhas a simple structure M K H = m K + m N − B K H , where m K and m N are the kaon andnucleon masses, and equal to M K H = 1405 MeV the calculated binding energy and widthof the KNC K H agree well with the results obtained by Akaishi and Yamazaki [1]. Theexplanation of the experimental data by the DISTO Collaboration B K H = 105(2) MeVand Γ K H = 118(8) MeV [3] goes beyond the description of the KNC K H proposed in [2].The analysis of the experimental data by the DISTO Collaboration in the molecule modelof kaonic nuclear clusters is carried out in a forthcoming paper.
References [1] Y. Akaishi and T. Yamazaki, Phys. Rev. C , 044005 (2002); T. Yamazaki and Y.Akaishi, Phys. Lett. B , 70 (2002); Phys. Rev. C , 045201 (2007).[2] M. Faber et al. , arXiv: 0912.2084 [nucl-th].[4] M. Maggiora et al. , (DISTO Collaboration), arXiv: 0912.5116 [nucl–ex].18 nalysis of cascade dynamics and x-ray yields for K − p and K − d atoms by Monte-Carlo method S.Z. Kalantari and M. Raeisi G.
Department of Physics, Isfahan University of Technology,Isfahan, 84156-83111,Iran
The cascade calculations presented here have led to a more detailed understanding of theatomic cascade in K − x atoms. The density dependence of the x-ray yields and numberof nuclear absorption, nuclear reaction and Stark mixing in different excited states arecalculated. We have analyzed our results to clear the answer of some important questionsabout the kaonic cascade dynamics. For example the results of forthcoming SIDDHARTAexperiment [1] are predicted. For this purpose we have used Monte-Carlo method. In thispresentation we review the cascade dynamics of kaonic atoms [2,3,4] and our Monte-Carlosimulation [5]. Our calculations show that two processes, nuclear absorption and Starkmixing, have an important role in atomic cascade at high density targets.In order to compare our results with experimental values we should calculate the x-rayyields per incoming kaon to the target. The value of Γ p (2 p strong interaction widthof K − p atoms) is determined by fitting our results with existing experimental data inKEK [6] and LNF [7]. Our estimated value for Γ p is 0.105 ± K − d and K − p atoms are done in different density.Because if it is possible, We can take Γ p as a free parameter then it can be determinedmore precisely by fitting the simulated x-ray curves with experimental results. We havealso predicted the optimum range of the target density to detect the higher x-ray yieldsfor forthcoming experiments on K − p and K − d atoms. The optimum range of the targetdensity are 0.03-0.06 of liquid hydrogen density (LHD) for K − p atoms and 0.06-0.2 ofLHD for K − d atoms.We have also investigated the kinetic energy distribution of K − p atoms and the role ofCoulomb transition on x-ray yields. The high kinetic energy component of K − p atomsappear as Doppler broadening profile in the experimental x-ray lines. We have calculatedthe average Doppler broadening contribution on the observed width in K α line by using thesimulated kinetic energy distribution of K − p atoms in 2 p -state at the instant of 2 p → s radiative transition. It should be used to extract the Γ had s from experimental results. References [1] C. Curceanu et al. , Eur. Phys. J. A (2007) 537; A. Romero, this proceeding.[2] M. Leon and H.A. Bethe, Phys. Rev. (1962) 636.[3] T.S. Jensen and V.E. Markushin, Lect. Notes Phys. (2003) 37.[4] M.Raeisi G. and S.Z. Kalantari, Phys. Rev. A (2009) 012510.[5] S.Z. Kalantari and M.Raeisi G., submitted to Phys. Rev. C (2009).[6] T.M. Ito et al. , Phys. Rev. C (1998) 2366.[7] G. Beer et al. , Phys. Rev. Lett. (2005) 212302; and private discussion with one ofthe authors (C. Curceanu). 19 earch for Double Antikaon Production in Nuclei byStopped Antiproton Annihilation Paul Kienle Excellence Cluster Universe, Technische Universit¨at M¨unchen, Germany
Recently antiproton annihilation in nuclei was proposed to search for deeply bound double-strange systems with S = -2 of light nuclei [1, 2]. A reanalysis of OBELIX data on stoppedantiproton annihilation in He at LEAR-CERN showed a surprisingly large productionprobability of ∼ − of strangeness S = -2 channels [3]. The corresponding momentumtransfer is large in such a reaction; thus the observed high formation probability indicatescompact systems as products. Such a scenario became recently support by the observationof a deeply bound S = -1 di-baryon resonance with a binding energy of ∼
100 MeV inhigh momentum transfer p − p collisions [4]. So there is reason to believe that one canproduce S = -2 di-baryon systems with still higher binding energies and densities usingantiproton annihilation at rest. This led to letters of intent for searches of dense, S = -2nuclear systems at CERN, FAIR and J-PARC [5, 6, 7] with dedicated detectors.In this contribution we present details of experimental approaches to search for the mostelementary S = -2 di-proton system using the antiproton annihilation reaction on Hetargets at rest ¯ p + He → K + K + X (S = 2) (1)where X denotes a di-proton with S = -2, which one can see as deeply bound K − K − pp system with a binding energy of about 200 MeV (double as high as the observed 100MeV of K − pp [4]). We furthermore assume that it is formed with a probability of ∼ − per antiproton [3], and that it decays with an assumed 10% probability into ΛΛ, theenergetically most favored channel. For an exclusive experiment we need a large acceptancedetector with the ability of identifying all charged particles, measuring their low momentafor determination the missing mass of K + K and their correlated ΛΛ pairs; the K → π + π − , and the Λ → pπ − decay being reconstructed via their respective invariant masses.A detailed simulation for the K + K and ΛΛ missing mass spectra has been performed fortwo detector concepts with different magnetic field configurations (cylindrical and dipolemagnets). With an antiproton beam of 0.65 GeV/c momentum, 3 . × antiprotons ina spill time of 3.5 s, a stopping efficiency of 3.9%, and assuming a double strangenessproduction probability of 10 − , one expects double-strangeness production of 9 . × per month. Assuming a conservative K + K ΛΛ branching ratio of 10% one produces 9 . × K + K ΛΛ events per month. Simulated ΛΛ and K + K missing mass spectra to bemeasured in the two setups during one month show well resolved lines with about 50 and20 events, respectively. References [1] W. Weise, arXiv: 0507.058 (nucl-th)[2] P. Kienle, J. Mod. Phys. A22 (2007) 365, and J. Mod. Phys. E16 (2007) 905[3] G. Bendiscioli, et al. , Nucl. Phys. A 797 (207) 109[4] T. Yamazaki, P. Kienle, M. Maggiora, and K. Suzuki in behalf of the DISTO collab-oration, Hyp. Int., DOI:10.1007/s10751-009-9997-5[5] J. Zmeskal, et al. , EXA/LEAP08 Proc. Hyp. Inter.[6] J. Zmeskal, et al. , New opportunities in the physics landscape of CERN, May 2009[7] M. Iwasaki, P. Kienle, H. Onishi, F.Sakuma, and J. Zmeskal, Lett. of Int. J-PARC,June 2009 20 ypernuclear production in ( K − stop , π ) reactions V. Krejˇciˇr´ık , , A. Ciepl´y Nuclear Physics Institute, ASCR, ˇReˇz, Czech Republic Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
We studied the Λ-hypernuclear production induced by the stopped kaon. The calculationwas performed within a framework of the distorted wave impulse approximation (DWIA)as described in detail by Gal and Klieb [1]. The formula for the capture rate R if can beexpressed as a product of three terms: R if = q f ω f q f ω f · R ( K − N → πY ) · R if /Y. (1)The first term is a kinematic factor, the second stands for the branching ratio of theelementary process and the third represents the rate per hyperon that contains the overlapof the initial and the final state wave functions.We used an effective potential model based on chiral symmetry [2,3] to generate the ele-mentary branching ratios, whereas previous authors took values derived from experiment.The pertinent branching ratios are R ( K − n → π − Λ) = 10 .
72, and R ( K − p → π Λ) = 5 . C a p t u r e r a t e ( i n un it s - ) experiment[K coul ]( p b )[K c ]( p b )[K eff ]( p b )[K DD ]( p b ) Figure 1: The production of
O inthe 1 S Λ state. We performed the calculation with three differentpion wave functions: ( π )-free wave, ( π b ) and ( π c )-generated by two different optical potentials, whichwere fitted to pion scattering data. We found thatthe capture rate is up to one order higher if the piondistortion is neglected while the other two optionsgive comparable capture rates.For the choice ( π b ), the sensitivity to the kaon wavefunction is demonstrated in Fig.1. Four different po-tentials were used to describe the K − -nucleus inter-action: pure electromagnetic [ K EM ] ( V = 0 MeV),chiral [ K χ ] ( V ≈
50 MeV), and two phenomenolog-ical ones [ K eff ] ( V ≈
80 MeV), and [ K DD ]( V ≈
190 MeV). It appears that the capturerate is a decreasing function of the central strong interaction potential depth which isdenoted by V .In the figure, our results are also compared with experimental data [4,5] (the first twobars). Although the data from different experiments do not match, we can say that ourresults are in better agreement with experiment than results of previous authors. Cur-rently, we have results for capture rates of the production of Li, Be, B, C, C, O,and we also tested the sensitivity of the model to various inputs. A more compete acountof our work was presented in [6].
References [1] Gal A., Klieb L.: Phys. Rev. C (1986) 956.[2] Kaiser N., Siegel P.B., Weise W.: Nucl. Phys. A , (1995) 325.[3] Ciepl´y A., Smejkal J.: arXiv:0910.1822 (2009).[4] G. Bonomi, talk at HYP-X @ J-PARC (2009).[5] Tamura H., et al.: Prog. Theor. Phys. Suppl. , (1994) 1.[6] Krejˇciˇr´ık, A. Ciepl´y: arXiv:0912.1505 (2009).21 he in-flight C ( K − , p ) reaction at KEK V.K. Magas , J. Yamagata-Sekihara , , S. Hirenzaki , E. Oset , and A. Ramos Departament d’Estructura i Constituents de la Mat`eria,Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan Departamento de F´ısica Te´orica and IFIC Centro MixtoUniversidad de Valencia-CSIC, Institutos de Investigaci´on de PaternaApdo. correos 22085, 46071, Valencia, Spain Department of Physics, Nara Women’s University, Nara 630-8506, Japan
We study the ( K − , p ) reaction on C with a kaon beam of 1 GeV/c momentum, payinga special attention at the region of emitted protons having kinetic energy above 600MeV, which was used to claim the evidence of a deep kaon nucleus optical potential, Re V ≈ − ρ/ρ MeV [1].We perform a Monte Carlo simulation of this reaction. The advantage of our method withrespect to the Green’s function method used in [1] is that it allows one to account notonly for quasi-elastic K − p scattering, but also for the other processes which contribute tothe proton spectra. We investigated the effect of K − absorption by one and two nucleons( K − N → πY and K − N N → Y N ) followed by the weak decay of the hyperon into πN ,which can also produce strength in the region of interest [2]. Our calculation is donewithin a local density approximation and considers final state interactions in terms ofmultiple scattering of the K − , p and all other primary particles on their way out of thenucleus. To compare our calculations with the published data [1] we have to also simulatethe experimental coincidence requirement of having, together with the energetic proton,at least one charged particle detected in the decay counters surrounding the target.We show that the above mentioned absorption mechanisms, not considered in the originalpublication [1], together with the coincidence simulation, allow us to explain the observedspectrum with ”standard” shallow kaon nucleus optical potential, Re V ≈ − ρ/ρ MeV,obtained in chiral models [2].Also, contrary to what was assumed in Ref. [1], we clearly see that the spectrum shapeis affected by the required coincidence [2]. In fact, the distorsion of the experimentalspectrum due to the coincidence requirement can easily be much bigger than the differ-ence between results for shallow and deep optical potentials. Thus, we conclude that theexperiment of Ref. [1] is not appropriate for extracting information on the kaon opticalpotential. The theoretical analysis of [1] was based on the assumption that the shape ofthe spectrum does not change with the coincidence requirement. Since we have shown thisnot to be case, the conclusions obtained there do not hold. Certainly, the experimentaldata without the coincidence requirement of [1] would be a much more useful observable.
References [1] T. Kishimoto et al. , Prog. Theor. Phys. (2007) 181.[2] V. K. Magas, J. Yamagata-Sekihara, S. Hirenzaki, E. Oset, A. Ramos, arXiv:0911.3614[nucl-th]; arXiv:0911.2091 [nucl-th]; A. Ramos, V. K. Magas, J. Yamagata-Sekihara,S. Hirenzaki, E. Oset, arXiv:0911.4841 [nucl-th].22 aonic nuclei
J. Mareˇs Nuclear Physics Institiute, 250 68 ˇReˇz, Czech Republic
We performed fully selfconsistent calculations of ¯ K nuclear bound states within the rel-ativistic mean field approach [1,2] with the view of exploring dynamical aspects of the¯ K –nucleus interaction. We scanned on the ¯ K coupling constant in order to cover a widerange of ¯ K separation energies.The widths Γ ¯ K of the ¯ K nuclear states are mostly determined by phase-space suppressionon top of the increase provided by the compressed nuclear density. A lower limit Γ ¯ K ∼ ±
10 MeV was placed on the widths of the 1 s ¯ K nuclear states expected for separationenergies in the range B ¯ K ∼ −
200 MeV. Fig. 1 illustrates that replacing ρ by ρ forthe density dependence of the 2 N absorption modes and switching on the π Λ decay modeadds further conversion width to the K − nuclear states. K - (MeV)050100150 G K - ( M e V ) pS; rpS; r pS, pL; rpS, pL; r CaK - Figure 1: Width of the 1 s K − nuclear state in K − Ca as function of the K − separationenergy, for absorption through ¯ KN → π Σ, with and without ¯ KN → π Λ, and assuming ρ or ρ dependence for ¯ KN N → Σ N .Significant polarization of the core nucleus was found in light nuclei for deeply bound K − nuclear states. The resulting nuclear central density is increased by a factor of 2. However,this enhancement, which follows closely the K − density, is limited to a region ≤ K − C, K − O), while it remains almost constant as function B K − in K − Pb.The dynamical calculation gives higher binding than the static calculation does. The gainin B K − increases monotonically with the K − separation energy. It is worth noting thatIm V K − may safely be ignored in the calculation of B K − above 100 MeV.We refer the interested reader to Refs. [1,2] for more detailed discussion of the dynamicaleffects for ¯ K deeply bound nuclear states.This work was supported in part by the GACR grant 202/09/1441. References [1] J. Mareˇs, E. Friedman, A. Gal, Nucl. Phys. A (2006) 84.[2] D. Gazda, E. Friedman, A. Gal, J. Mareˇs, Phys. Rev. C (2007) 055204.23 EANNIS: a liason between theory and experimentin antikaon physics
J. Marton Stefan Meyer Institute, 1090 Vienna, Austria
The Network LEANNIS (Low-energy Antikaon Nucleon and Nucleus Interaction) is de-voted to the current research in experiment as well as in theory on kaonic atoms andkaonic nuclei bound by the strong force. It is a networking activity in the Europeanproject HadronPhysics2 of the 7 th framework program. 12 institutes from 5 EU countries(Austria, Finland, Germany, Italy and Poland) and institutes from the associated countryJapan participate in LEANNIS. Many open questions are addressed in new experimentlike SIDDHARTA at LNF [1] and FOPI [2]. For the interpretation of the experimentaldata a close connection with theoreticians is essential and provided by the network. Thefield of low-energy antikaon interaction has many facets. Even the study of the most sim-ple kaonic atom - kaonic hydrogen - is a challenge in experiment and theory. The so-calledkaonic hydrogen puzzle was solved by the experiment KpX [3] and verified by DEAR [4]but more precise data of the observables (shift and width of the ground-state due to K − -pinteraction is main topic of the SIDDHARTA experiment taking advantage of new detec-tors (silicon drift detectors) for x ray spectroscopy. On the other hand the correspondingobservables of kaonic deuterium are a hot topic since they are necessary to extract theisospin dependent K − -nucleon scattering lengths. For the first time kaonic deuterium wasstudied by SIDDHARTA very recently. The extraction of the scattering lengths is subjectof intense theoretical work [5] taking into account the corrections (e.g. isospin breaking)to the Deser-Trueman formula.Many questions about kaonic nuclei are still open: production mechanism, binding en-ergy, decay widths etc. Experimental data claim the observation of kaonic nuclei in differ-ent reactions using stopped K − , proton-induced reaction or antiproton absorption [6,7].However, the overall picture is not coherent since the binding energies and decay widthextracted from data with different production reactions vary in a broad range. On thetheoretical side studies with effective field approaches, Faddeev calculations and phe-nomenological approaches also differ in a wide rang. Certainly this situation calls for newdedicated experiments (fully exclusive experiments) and also new theoretical studies inorder to design the experiments. To promote the field the LEANNIS activities are con-centrated on developing new strategies, both in experimental and theoretical sectors, toattack the still many open problems in the field. The development of new experimentalmethods and techniques will profit from this coordinated network. Furthermore, majorEuropean institutes working in this field are participating in this network, therefore aplatform is created to strengthen and bundle the research efforts. References
A827 (2009)312C.[3] M. Iwasaki et al., Phys. Rev. Lett. (1997) 3067.[4] G. Beer, et al., Phys. Rev. Lett. (2005) 212302.[5] M. Lage, U.-G. Meißner and A. Rusetzky, Hyp. Int. (2009) 69.[6] M. Agnello et al., Phys. Rev. Lett. 94, 212303 (2005).[7] T. Yamazaki et al.,Hyp. Int. (2009) 181, arXiv: 0810.5182 [nucl–ex].24 ecent results on K − absorption at reston few nucleon systems with FINUDA S. Piano INFN Sezione di Trieste, via A. Valerio 2, 34127 Trieste, Italy
The FINUDA experiment is dedicated to the study of kaonic interactions and is installedat the DAΦNE collider (INFN Laboratori Nazionali di Frascati - Italy) [1]. The experi-mental setup consists of a large acceptance ( > π sr) magnetic spectrometer with highmomentum resolution and excellent particle mass identification. In FINUDA, negativekaons are absorbed at rest in nuclear targets, which are constituted by thin plates; thus,allowing for A dependence studies, from Li to V.While the K − stop N → Y π one-nucleon absorption is the basic mechanism for hypernu-clear production, the negative kaon can initially interact also with two or more nucle-ons, K − (2 N ) → Y N, K − (3 N ) → Y ( N N ) , K − (4 N ) → Y ( N N N ), leading to hyperon-nucleons final states without pion emission. The experimental study of mesonless multin-ucleon absorption received a strong boost after the Akaishi and Yamazaki [2] predictionsof the existence of Bound Kaonic Nuclear (BKN) states because their formation can beviewed as the intermediate step of a K − many-body absorption.The FINUDA studies of kaon absorption on few nucleon systems were carried out by ex-amining Λ − p ( d, t ) correlations [3] [4] [5]. Regardless of A , the Λ − p ( d, t ) pairs are foundto be preferentially emitted in opposite directions. The observation of a nearly constantproduction rate of back-to-back Λ − p ( d, t ) pairs suggests that the absorption of K − atrest in nuclei may proceed through the formation of intermediate BKN states. Moreover,the experiment could fruitfully apply the quasi-invariant mass spectroscopy technique,thanks to the capability to detect completely the full topology of the final states, also bymeans of the missing mass information. In the Λ p [3] and Λ d [4] invariant mass spectratwo strong signatures of BKN states were found and the binding energy and the widthwere provided.The analysis of the FINUDA second data taking are in the final stages and will allow toobtain spectra from different targets. The A dependence may play a key role to under-stand the negative kaon multinucleon absorption and to disentangle the effect of FinalState Interactions. References [1] FINUDA Collaboration, M. Agnello et al. , Phys. Lett.
B622 (2005) 35[2] Y. Akaishi, T. Yamazaki,
Phys. Rev.
C65 (2002), 044005T. Yamazaki, Y. Akaishi,
Nucl. Phys.
B535 (2002), 70Y. Akaishi, A. Dote, T. Yamazaki,
Phys. Lett.
B613 (2005), 140[3] FINUDA Collaboration, M. Agnello et al. , Phys. Rev. Lett. (2005), 212303[4] FINUDA Collaboration, M. Agnello et al. , Phys. Lett. B654 (2007), 80FINUDA Collaboration, M. Agnello et al. , Eur. Phys. J.
A33 (2007), 283[5] FINUDA Collaboration, M. Agnello et al. , Phys. Lett.
B669 (2008), 22925
IDDHARTA recent results
A. Romero Vidal on behalf of the SIDDHARTA Collaboration
Laboratori Nazionale di Frascati-INFN, Frascati (Rome)
The SIDDHARTA experiment at DA Φ N E studies the X-ray spectroscopy of exotic atoms,as kaonic helium ( He and He ) and kaonic hydrogen and deuterium. For the case of kaonichydrogen and deuterium the strong interaction leads to a shift ∆ E of the energy of thefundamental 1 s level compared to the value calculated from electromagnetic interactiononly, and a broadening Γ due to the absorption of the hadron by the nucleus. Thesequantities can be obtained by comparing the measured energies of the X-ray transitionsto the 1 s level to the purely QED calculated ones.A measurement of the ∆ E and Γ for the K-H and the K-d would provide very valuableinformation for a better comprehension of the low energy QCD , improving the measure-ments done by
KpX [1] and
DEAR [2] experiments, and will allow to determine theisospin dependent kaon-nucleon scattering lengths [3].The SIDDHARTA setup is described in detail in [3]. It uses the low-energy kaon beamfrom the DA Φ N E e + e − collider , stopping kaons in a high-density cryogenic gas targetand employs 144 novel Silicon Drift Detectors (SDDs) 1 cm to measure the X-rays energy.A system of two scintillators placed above (in coincidence with entrance window of setup)and below the beam pipe are used to dectect the kaons coming from the Φ → K + K − reaction, and to deliver the trigger signal to the SDD detectors, eliminating in this waythe background produced by losses from circulating beams (main source of background).The data taking campaign of SIDDHARTA: a measurement of kaonic hydrogen, thefirst exploratory measurement of kaonic deuterium, precision measurements of KHe and KHe ended by middle November 2009. Presently the data analyses is undergoing, withvery promising results. For preliminary analyses results see [5]. References [1] M. Iwasaki et al., Phys. Rev. Lett. 78 (1997) 3067.[2] G. Beer et al., Phys Rev. Lett. 94 (2005) 212302.[3] J. Zmeskal, Progr. Part. Nucl. Phys. 61 (2008) 512.[4] T. Ishiwatari, Nucl. Instr. Meth. Phys. Res. A 581 (2007) 326.[5] http://agenda.infn.it/getFile.py/access?contribId=1&sessionId=1&resId=0&materialId=slides&confId=184126
GP formation in antiproton annihilation at rest
G. Bendiscioli , , T. Bressani , P. Salvini Dipartimento di Fisica Nucleare e Teorica dell’Universita’ di Pavia,Pavia, Italy Dipartimento di Fisica Sperimentale, Universita’ di Torino, Torino, Italy Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Italy
In this paper we report data on pion spectra reinforcing the hypothesis of quark-gluonplasma formation in p He annihilation at rest previously reported [1]. According to somemodels the transition from a hadronic phase to QGP is expected to occur above a criticaltemperature of the order of 150-200 MeV [2] and one of its expected signatures is a highproduction of strangeness [3]. We experimentally investigated the K + , K − production inthe p annihilation at rest on H and He gas targets and found that in reaction channelsselected as annihilations with involvement of more than one nucleon and without neutralmeson production the ratio between the K + production on He and that on single nucleon,i.e. H, raise up to 30 [1], while the strangeness increase observed for the global set ofevents was only about 2 times. The data were obtained with the spectrometer Obelixworking at the complex LEAR of CERN in the years 1992-1996.
Multiplicity2 3 4 5 6 To t a l e n e r g y ( G e V ) K i n e t i c e n e r g y ( G e V ) To t a l e n e r g y ( G e V ) K i n e t i c e n e r g y ( G e V ) Figure 1: Pion mean energy E π vs. multiplicity for reaction channels with the followingdetected particles: (crosses) π ± ; (circles) π ± ± ; (triangles) π ± p; (squares) π ± K ± p. (a) Allevents; (b) events without neutral meson production [1]. The E π for H (+) is calculatedas 2m proton divided by the π ± multiplicity.In Figs.1a,b the π ± mean kinetic energy results to be equal or higher than the criticaltemperature Tc ≈
170 MeV predicted for the QGP formation. Taking into account thatthe qq state masses are higher than the single quarks masses, from figs.1 the quarks kineticenergy (corresponding to the temperature in the statistical picture [4]) is high enough tobe compatible with the occurrence of QGP. This means that at least two conditionspredicted for the QGP formation are well satisfied in p He annihilation at rest.
References et al. ,Nucl.Phys.A760(2005)34, G.Bendiscioli et al. ,Nucl.Phys.A815(2009)672 F.Karsch et al. , Nucl.Phys.B605(2001)579, J. Rafelski, Nucl. Phys. A418(1984)215c3 J. Rafelski and B. M˝uller, Phys. Rev. Let4 D. Evans et al. , J. Phys. G: Nucl. Phys. 25(1999)20927 he trigger system for the AMADEUS experiment
A.Scordo, M.Bazzi, G.Corradi, A.Romero Vidal, D.Tagnani, O.Vazquez Doce
Laboratori Nazionali di Frascati, INFN, Via E. Fermi 40, 00044, Frascati, IT
Multi-Pixel Photon Counters (MPPC) consist of hundreds of micro silicon AvalanchePhotoDiodes (APD) working in Geiger mode. The high gain, low noise and low volt-age values needed for operating of these relatively new devices, together with their goodbehaviour in magnetic fields make them ideal for the readout of scintillating fibers asfront-end detectors, as planned for the trigger system of the AMADEUS experiment. Afirst test of a prototype of MPPC+Sci-Fi setup was performed on the DAΦNE collider atLNF-Frascati. 5 scintillating fibers ( ∼ cm length ) were coupled at both sizes with MP-PCs and were placed few centimiters under the lower scintillator of SIDDHARTA’s KaonMonitor [1] wich is located 6 cm below the interaction point. The Kaon Monitor consistsin 2 scintillators mounted above and below the beam pipe in order to detect a K-/K+couple produced ind the Φ decay in back-to-back configuration and also MIPs comingfrom the interaction point; KM signal is the coincidence between upper and lower scin-tillator. Radiofrequency of the machine is taken as reference time; this signal is providedeach time a collision between e+ and e- bunches occurs ( ≃ M Hz ). Timing separationbetween MiPs and Kaons in the KM is ≃ ns Triggering the acquisition with the SID-DHARTA’s Kaon Monitor and selecting signals coming from Kaons or MIPs, charge andtiming information were collected.
ADC spectra
200 400 600 800 1000 1200 1400 adc channel c oun t s tdc channel (25ps/ch) c oun t s Figure 1: ADC and TDC spectra for MPPC+Sci-Fi setup mounted on DAΦNE collider(left picture); total spectra (black), signals in coincidence with Kaons (red) and with MIPs(green) are shown.Using a Sci-Fi+MPPC setup detection of Kaons coming from DAΦNE is then possiblewith a time resolution of ≃ ps . References [1] C. Curceanu et al., Eur. Phys. J. A 31 , (2007) , 537-53928 wo- and three-body resonancesin the ¯ K N N − π Σ N system N.V. Shevchenko Nuclear Physics Institute, 25068 ˇReˇz, Czech Republic
One of the most important characteristics of a two-body interaction is existence andproperties of its bound states or resonances. When the interaction is used in a few- ormany-body calculation they also strongly influence the properties of the few- or many-body system. We investigate the dependence of the three-body resonance properties inthe ¯
KN N system on the different models of ¯ KN interaction, providing one or two polesfor Λ(1405) resonance.It is known, that ¯ KN interaction is strongly coupled to the π Σ channel through Λ(1405)resonance. However, the nature of the resonance is a question. A usual assumption is thatΛ(1405) is a resonance in π Σ and a quasi-bound state in ¯ KN channel. There is also anassumption suggested by a chiral model, that the bump, which is usually understood asΛ(1405) resonance, is an effect of two poles.In [1] isospin symmetry breaking phenomenological ¯ KN − π Σ potentials were constructedin order to check whether it is possible to reproduce all existing experimental data on K − p system with one- and two-pole structures of Λ(1405). It turned out, that both versionsof the potential can reproduce existing data on K − p scattering and K − p atom level shiftequally well in such a way, that it is not possible to draw conclusions about “nature” ofΛ(1405) resonance.One possible way to clarify the situation is to perform a few- or many-body calculationusing two versions of ¯ KN − π Σ potential as an input. Having this in mind, we repeatedour calculations of ¯
KN N − π Σ N system [2, 3] searching for three-body poles in it. Asbefore, coupled-channel Faddeev equations in AGS form were solved.Not only basic ¯ KN − π Σ interaction was changed during the calculations, other two-body inputs were also improved. In particular, we used new two-term potential for
N N interaction [4], which reproduce Argonne v N N phase shifts, having repulsion at shortdistances, and corresponding scattering length and effective radius.Also a new set of Σ N ( − Λ N ) potential parameters was found in order to reproduce existingexperimental data on Σ N and Λ N scattering. The I = 3 / N , while I = 1 / N is connected with Λ N channel. Due to this acoupled-channel I = 1 / N − Λ N potential was constructed first, then a correspondingone-channel optical potential for Σ N was derived.Our preliminary results show, that while two versions of the ¯ KN − π Σ interaction describetwo-body experimental K − p data indistinguishably well, the three-body results for thepole positions in ¯ KN N − π Σ N system strongly depend on the two-body ¯ KN − π Σ input.More detailed calculation is in progress.
Acknowledgments.
The work was supported by the Czech GA AVCR grant KJB100480801.
References [1] J. R´evai, N.V. Shevchenko, Phys. Rev.
C 79 (2009) 035202.[2] N.V. Shevchenko, A. Gal, J. Mareˇs, Phys. Rev. Lett. (2007) 082301.[3] N.V. Shevchenko, A. Gal, J. Mareˇs, J. R´evai, Phys. Rev. C 76 (2007) 044004.[4] P. Doleschall, private communication . 29 he investigation of
Λ(1405) state in the stopped K − reaction on deuterium T. Suzuki , J. Esmaili , , and Y. Akaishi , Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan RIKEN Nishina Center, RIKEN, Saitama 351-0198, Japan Department of Physics, Isfahan University of Technology, Isfahan 84156-83111, Iran College of Science and Technology, Nihon University, Chiba 274-8501, Japan
Recently, intensive discussion of the problem of the deeply bound ¯ K nuclei reached to thereconsideration of Λ(1405) state as the theoretical basis of the binding of ¯ K nuclei, andthe old question of the nature of Λ(1405) became a modern subject by the new interest.In contrast to the interpretation of Λ(1405) as the ¯ KN quasi-bound state at 1405 MeV/ c ,a two-pole hypothesis, by which Λ(1405) consists of two poles at 1420 and 1390 MeV/ c couple mainly with ¯ KN and Σ π channels, respectively, thus the less attractive ¯ KN in-teraction leads shallower binding of ¯ K nucleus, was proposed by several authors [1] [2].On the other hand, a very recent theoretical analysis has clarified that the (Σ π ) invari-ant mass spectra after K − absorption in d do reflect resonant formation of Λ(1405) (orΛ(1420)) and thus are capable of distinguishing different Ansatz’s [3].We have discussed a new experimental proposal [4] by means of the stopped K − reactionon liquid deuterium at J-PARC K1.8BR beamline with E15 [5] /E17 [6] experimentaldevices, so as to give a new precision- and high-statistics-data of (Σ π ) mass spectra toexamine the issue, Λ(1405) or Λ(1420), in the most reliable way, and thus to answer themost fundamental questions of ¯ KN interaction and ¯ K nuclei. Beam
Magnet (cid:13)D5
BLC1 BLC2T0
Solenoid MagnetSolenoid MagnetCDC
CDHCDH
CDC
Main (cid:13)DegraderAdjustable (cid:13)DegraderLC1LC2 E0 BLC3 Cryostatdeuteron target cellFinal Focus(FF) zyx c oun t s / ( M e V / c ) M(( Sp ) ) (MeV/ c ) L (E=1420,W=40) theory L (E=1420,W=40) experiment L (E=1405,W=40) theory L (E=1405,W=40) experiment Figure 1: Left: A schematic view of the proposed experiment. Right: Theoretical andexpected M (Σ π ) spectra. References [1] V.K. Magas, E. Oset, and A. Ramos, Phys. Rev. Lett. (2005) 052301.[2] T. Hyodo and W. Weise, Phys. Rev. C (2008) 035204.[3] J. Esmaili, Y. Akaishi, and T. Yamazaki, ArXiv:0909.2573.[4] T. Suzuki et. al , Proposal for J-PARC 50 GeV Proton Synchrotron (J-PARC P30),2009.[5] M. Iwasaki, T. Nagae et. al , Proposal for J-PARC 50 GeV Proton Synchrotron (J-PARC E15), 2006.[6] R.S. Hayano, H. Outa et. al , Proposal for J-PARC 50 GeV Proton Synchrotron (J-PARC E17), 2006. 30 nalysis of the K − He interactions in the KLOE driftchamber
O. Vazquez Doce on behalf of the AMADEUS Collaboration LNF-INFN, Enrico Fermi 40, 00044, Frascati (Rome), Italy
The AMADEUS experiment [1] at the DaΦne accelerator of the Frascati National Labora-tories (Italy) of INFN, will perform, for the first time, full-acceptance studies of antikaoninteraction in light nuclei, with a complete experimental program for the case of thekaonic clusters. Studying the absorption of antikaon by the nucleus will provide informa-tion concerning the ¯ KN interaction and the modification of the kaon mass in the nuclearmedium.A preliminar study of these kind of hadronic interactions is being done by the AMADEUScollaboration by analyzing the existent KLOE data [2].The KLOE drift chamber [3] contains mainly helium, and a Monte Carlo study showsthat 0.1% of the K − flying through the chamber should be stopped in the gas, giving anunique scenario to study the hadronic interactions in such an ”active target”.Preliminary results of the analysis of a sample of the 2005 KLOE data (corresponding toan integrated luminosity of ∼ . f b − ) has shown the capabilities in performing nuclearphysics measurements with the KLOE detector. The strategy is focused on the identifi-cation of possible specific decay products of the kaonic nuclear clusters: specifically intochannels containing the Λ(1116) hyperon, present in most of the expected decay channelsof the bound states. An excellent result has been already achieved with a precise determi-nation of the lambda mass, the statistical error is below 3 KeV. The measurement showsan excellent mass resolution FWHM ∼
700 KeV/c , found in the reconstruction of thedecay of Λ into proton and negative pion [4].Vertices produced by these lambda particles with protons or deuterons are searched alongthe K − (tracked or extrapolated) decay path, or along the lambda path extrapolatedbackwards, as direct signals of the formations of these clusters, or absorptions of K − by the nucleons of the gas nuclei. Also neutral vertices are seached for, as the expectedresulting from the formation of a lambda(1405) decaying to neutral particles, Σ π . Inthis case the excellent performance of the electromagnetic calorimeter and its resolutionfor the detection of photons is crucial.In conclusion, a selection of thousands of Λ(1115) baryons has been made from ∼ . f b − of KLOE data, allowing to investigate diferent kind of reaction products from the interac-tion of K − in the drift chamber. The number and the quality of the signal opens the doorfor studies of many hadronic physics hot topic items, proving KLOE to be a powerfulinstrument for performing very interesting physics in the strange nuclear and hadronicphysics sectors too. References ntikaon Interactions with Nucleons and Nuclei
Wolfram Weise
Physik-Department, Technische Universit¨at M¨unchen, D-85747 Garching, Germany
Precision measurements of kaonic hydrogen and their analysis extracting the real andimaginary parts of the K − p scattering length set important quantitative constraints forchiral SU(3) dynamics. The best data so far have been obtained at LNF (the DEARexperiment) and earlier at KEK (the PS-E228 experiment). The K − p scattering lengthsdeduced from these measurements are not fully consistent: a ( K − p ) = − .
47 ( ± .
10) + i .
30 ( ± .
17) [fm] [DEAR] and a ( K − p ) = − .
78 ( ± .
18) + i .
49 ( ± .
37) [fm] [KEK].Theoretical analyses of the kaonic hydrogen energy shift (∆ E ) and width (Γ), basedon chiral SU(3) dynamics, have been performed in Refs. [1,2]. The calculations favourslightly the earlier KEK data. It is thus important to resolve this issue at the higherlevel of precision reached with the SIDDHARTA experiment at LNF. High-precision ¯ KN threshold data and accurate π Σ mass spectra are crucial in order to guide subthresholdextrapolations of the antikaon-nucleon interaction into domains relevant for possible ¯ K -nuclear quasibound states.Extrapolations of the ¯ KN ↔ π Σ coupled-channels dynamics into regions below K − p threshold can be tested by examining in detail the shapes and locations of the three π + Σ − , π − Σ + and π Σ invariant mass distributions. They differ primarily due to the I = 1 component of the amplitude as it interferes with the dominant I = 0 part. Thereis not just a single π Σ mass spectrum determining uniqely the position and width of theΛ(1405). The π Σ mass distributions depend on the process considered.Concerning the quest for quasibound K − pp systems, the present status of the theorycan be summarized as follows. Two basic strategies have been employed: i) three-bodycalculations solving Faddeev equations with separable interactions [3], and ii) variationalcalculations using phenomenlogical input [4] or ¯ KN effective interactions based on chiralSU(3) dynamics [5]. Even though all input interactions in these calculations have beentuned to reproduce threshold ¯ KN observables or the Λ(1405), one encounters a broadband of binding energies ranging between about 20 and 80 MeV, while the decay widthscover values between 40 and 110 MeV.A necessary (though not sufficient) condition for reliable subthreshold extrapolations isa controlled theoretical framework. Chiral SU(3) effective field theory combined withcoupled-channel methods provides such a framework, but it requires a sufficiently largeand accurate empirical data base in order to proceed.While unambiguous conclusions about quasibound antikaon-nuclear systems can at presentnot yet be drawn, further progress is expected to come from detailed investigations of ex-clusive final states following K − absorption and photon- or hadron-induced K + productionon nuclei, in order to constrain the underlying coupled-channel dynamics. References [1] B. Borasoy, R. Nissler and W. Weise, Eur. Phys. J
A 25 (2005) 79; Phys. Rev. Lett. (2005) 213401.[2] R. Nissler, PhD thesis, Univ. of Bonn (2007); B. Borasoy, U.-G. Meißner and R.Nissler, Phys. Rev. C 74 (2006) 055201.[3] N.V. Shevchenko, A. Gal and J. Mares, Phys. Rev. Lett. (2007) 082301; N.V.Shevchenko, A. Gal, J. Mares and J. R´evai, Phys. Rev. C 76 (2007) 044004; Y.Ikeda and T. Sato, Phys. Rev.
C 76 (2007) 035203, Phys. Rev.
C 79 (2009) 035201.324] T. Yamazaki and Y. Akaishi, Phys. Lett.
B 535 (2002) 70; Phys. Rev.
C 76 (2007)04520; S. Wycech and A.M. Green, Phys. Rev.
C 79 (2009) 014001.[5] T. Hyodo and W. Weise, Phys. Rev.
C 77 (2008) 03524; A. Dot´e, T. Hyodo and W.Weise, Nucl. Phys.
A 804 (2008) 197, Phys. Rev.
C 79 (2009) 014003.33 xtraction of the
K N subthreshold amplitudes from K − atoms S. Wycech
Soltan Institute for Nuclear Studies, Warsaw, Poland
The K mesic atoms offer a chance to look directly into subthreshold K − N scatteringamplitudes. This region is of interest as there are conflicting models of the Λ(1405) res-onance and related amplitudes. In K − atoms, the meson interacts with bound nucleonsand the energy in the K − N system is negative as a result of the binding and K − N re-coil energies. Most of the atomic data involve heavy nuclei. These are not useful for thepurpose since many nucleons participate in interactions and nuclear effects are sizable.Light nuclei are convenient as the nucleon binding energies in H, H, H, He and Hespan the 0- 20 MeV region in a quasi-continuous way. With systematic experiments onecan extract the K − N scattering amplitudes below the K − N threshold down to about -35 MeV. At this moment one has only K H [1] and K He [2] data. One should look withmore care into usually neglected ”upper level” widths in heavier K atoms. In particularone notices stronger absorption in nuclei with large proton binding (C). There is a possi-bility to extract Im a ( K − n ) from large nuclei (Pb,U). Some old unprecise measurementsare worthy of repetition.A similar extraction has been performed with the light antiprotonic atoms [3]. Absorptive p − N amplitudes shown in the figure indicate existence of S and P-wave subthresholdquasi-bound states which find additional evidence in other experiments [3,4]. -40 -30 -20 -10 0 10 123 ENERGY (MeV) f m + He He H H + n – pIm a p Im a n Im b p Im b n Figure 1: The absorptive p − N scattering lengths (Im a, squares) and scattering volumes(Im b, blobs) extracted from light atoms. The lines present Paris-model calculations. References [1] G. Beer et al. Phys.Rev.Lett (2009) 212302.[2] S. Okada et al. Phys.Lett. B653 (2007) 387.[3] S. Wycech et al. Phys.Rev.
C76 (2007) 014311.[4] J-P. Dedonder et al. Phys.
C80 (2009) 0452207.34 xperimental confirmation of the
Λ(1405)
Ansatzfrom resonant formation of a K − p quasi-bound statein K − absorption by d , He and He Toshimitsu Yamazaki , Department of Physics, University of Tokyo, Tokyo, 116-0033 Japan RIKEN NishinaCenter, Wako, Saitama, 351-0198 Japan
Where is the position of the I = 0 L = 0 K − p quasi-bound state? This question is directlyconnected to the strength of the s-wave I = 0 ¯ KN interaction. Traditionally, the Λ(1405)resonance is identified to this state, and a strongly attractive ¯ KN interaction is indicated[1]. Recently, another theoretical framework including a double-pole hypothesis has beenproposed, claiming that the K − p bound state is located around 1420 MeV [2,3]. Wecall such a hypothetical state “Λ ∗ (1420)”. It is vitally important to distinguish betweenΛ(1405) and Λ ∗ (1420) experimentally, but there seem to be lots of confusing statementsconcerning the strategy as to how valid experimental evidence can be obtained.In our recent work [4] we have shown that the Σ π invariant-mass spectra ( M Σ π ) in stopped- K − absorption in He, He and d are governed by the spectator momentum distributions of t , d and n , respectively, and do reflect the resonant formation of a quasi-bound K − p state,contrary to the past interpretation in terms of the non-resonant direct-capture process.Thus, the issue of the location of the K − p resonance state can be examined experimentallyby a quantitative comparison of an observed M Σ π spectrum with predicted theoreticaldistributions including resonant formation. We made a χ analysis of old bubble-chamberdata of M Σ π ( He) by varying the mass ( M ) and width (Γ) of an assumed resonance andfound a significant minimum in the M − Γ contour presentation of χ at M = 1405 . +1 . − . MeV /c and Γ = 25 . +4 − MeV . (1)Thus, the Λ ∗ (1420) Ansatz is excluded by more than 99.99% confidence. However, theΛ(1405) signal does not appear as a separate peak, but as a small component of thesteeply falling tail, and this discrimination seems to be delicate. One would hope to havea more clear-cut case.More recently, we have pointed out [5] that the use of a deuteron target in the reaction,stopped − K − + d → X + n, (2) X → Σ + π, (3)can provide a more decisive conclusion. Since the deuteron wavefunction is composed oflow- and high-momentum components, the dominant “quasi-free (QF)” shape of M Σ π isnarrow, whereas its tail, resulting from the high-momentum component of d , extends tothe region where a resonant formation of Λ(1405) (but not of Λ ∗ (1420)) can be revealedas a separate peak. We investigate this problem in detail. References [1] Y. Akaishi, T. Yamazaki, Phys. Rev. C (2002) 044005.[2] D. Jido, J. A. Oller, E. Oset, A. Ramos and U.-G. Meißner, Nucl. Phys. A (2003)181.[3] T. Hyodo and W. Weise, Phys. Rev. C (2008) 035204.[4] J. Esmaili,Y. Akaishi and T. Yamazaki, arXiv:0906.0505v1.[5] J. Esmaili,Y. Akaishi and T. Yamazaki, arXiv:0909.2573.35 ndication of a strongly bound dense K − pp stateformed in the pp → p Λ K + reaction at 2.85 GeV T. Yamazaki , , M. Maggiora , P. Kienle , , K. Suzuki , on behalf of the DISTO collaboration Department of Physics, University of Tokyo, Tokyo, 116-0033 Japan RIKEN NishinaCenter, Wako, Saitama, 351-0198 Japan Dipartimento di Fisica Generale “A. Avo-gadro” and INFN, Torino, Italy Stefan Meyer Institute for Subatomic Physics, AustrianAcademy of Sciences, Vienna, Austria Excellence Cluster Universe, Technische Univer-sit¨at M¨unchen, Garching, Germany
Recently, it was predicted that a strongly bound K − pp system with a short p - p distance[1,2] can be formed in a p + p → p + Λ ∗ + K + reaction with an enormously large stickingprobability between Λ ∗ ≡ Λ(1405) and p due to the short range and high momentumtransfer of the pp reaction [3,4]. Here, we report that existing data of a DISTO experimentshow an evidence for this exotic formation. Preliminary reports have been published [5,6].We have analyzed data of the DISTO experiment on the exclusive pp → p Λ K + reactionat 2.85 GeV to search for a strongly bound K − pp ( ≡ X ) state to be formed in the pp → K + + X reaction. The observed spectra of the K + missing-mass and the p Λ invariant-mass with high transverse momenta of p and K + revealed a broad distinct peak with amass M X = 2265 ± stat ) ± syst ) MeV/ c and a width Γ X = 118 ± stat ) ± syst )MeV.The X production rate is found to be as much as the Λ(1405) production rate. Sucha large formation is theoretically possible only when the p - p (or Λ ∗ - p ) distance in X isshorter than 1.7 fm , whereas the average N - N distance in ordinary nuclei is 2.2 fm [3,4].No candidate other than K − pp for X with such large formation is predicted so far. Thedominance of the formation of the observed X at high momentum transfer gives directevidence for the compactness and thus high density of the produced K − pp cluster.The mass of X corresponds to a binding energy B K = 105 ± stat ) ± syst ) MeVfor X = K − pp . The observed binding energy is close to the mass M ( p Λ) ∼ c of the K − pp candidate observed by FINUDA [7]. It is larger than the original prediction,thus suggesting additional effects to be investigated [4]. The large width seems to be un-derstood by the dense nature of K − pp . The theoretical claims for shallow ¯ K binding [8,9]do not seem to be in agreement with the present observation. References
C 65 , 044005 (2002).2 T. Yamazaki and Y. Akaishi, Phys. Lett.
B 535 , 70 (2002).3 T. Yamazaki and Y. Akaishi, Proc. Jpn Acad.
B 83 , 144 (2007).4 T. Yamazaki and Y. Akaishi, Phys. Rev.
C 76 , 045201 (2007).5 T. Yamazaki et al. , Hyperfine Interactions , 181 (2009).6 M. Maggiora et al. , Hyp-X Proceedings; arXiv:0912.5116 [hep-ex].7 M. Agnello et al. , Phys. Rev. Lett. , 212303 (2005).8 D. Jido, J.A. Oller, E. Oset, A. Ramos and U.-G. Meissner, Nucl. Phys. A725 , 181(2003); V.K. Magas, E. Oset and A. Ramos, Phys. Rev. Lett. , 052301 (2005).9 T. Hyodo and W. Weise, Phys. Rev. C 77 , 035204 (2008); A. Dot´e, T. Hyodo and W.Weise, Phys. Rev.
C 79 , 014003 (2009).36 he AMADEUS pro ject – precision studies of thelow-energy antikaon nucleus/nucleon interaction
J. Zmeskal for the AMADEUS Collaboration Stefan-Meyer-Institut f¨ur subatomare Physik, Vienna, Austria
The planned series of measurements with AMADEUS (Antikaon Matter At DAΦNE: Ex-periments with Unravelling Spectroscopy) [1] will provide high precision data for a bet-ter understanding of the strong interaction in the low-energy regime due to the studyof antikaon nucleus/nucleon dynamics. To achieve these goals AMADEUS will makeuse of the KLOE detector system at LNF, which is ideally suited for these measure-ments due to its large central drift chamber (CDC), which provides excellent chargeparticle identification and tracking. In addition, an almost 4 π calorimeter for the de-tection of neutral particles is surrounding the CDC. R&D work has already startedto construct a dedicated target and trigger system for optimizations on the kaon stop-ping efficiency and for further improvements of the signal to background ratio (Fig. 1). half-toroidal cryogenic target celltarget cell 1 st inner-layer ofscintillating fibrefib i 1 1 fiber size: 1x1mm nd inner-layer ofthree outer-layersof scintillating fibre scintillating fibrefiber size: 1x1mm fiber size: 1x1mm Fig. 1: A sketch of the AMADEUS target anddetector system within KLOE.
The scientific case of AMADEUS dealswith one of the most important, yet un-solved, problems in hadron physics: howthe hadron masses are generated,how the hadron interactions changein the nuclear medium and what isthe structure of cold dense hadronicmatter.
With AMADEUS these prob-lems will be attacked by detailed studiesof the antikaon nucleus/nucleon interac-tion at low-energy and as well a dedicatedsearch is planned to look for an experi-mental proof of the existence of antikaon-mediated deeply bound nuclear systems [2]. If they exist, antikaon bound nuclear states( ¯ K -nuclear clusters) will indeed offer ideal conditions for investigating the way in which thespontaneous and explicit chiral symmetry breaking pattern of low-energy QCD changesin the nuclear environment. Moreover, AMADEUS will measure low-energy charged kaoncross sections on He and He and high statistic data sets will be available to studyresonance states like Λ(1405) or Σ(1385) to understand their structure and also theirbehaviour in a nuclear medium.
References ist of Participants
Family name Given name InstitutionAkaishi Yoshinori RIKEN/Nihon University (Japan)Aslanyan Petros Joint Institute for Nuclear Research, LHEP (Russia)Berger Martin TU-M¨unchen (Germany)Bosnar Damir Univ. Zagreb (Croatia)Chen Jia-Chii TU-M¨unchen (Germany)Cieply Ales NPI, Rez (Czech Republic)Curceanu Catalina Oana LNF, INFN (Italy)Donoval Jan NPI Rez (Czech republic)Epple Eliane TU-M¨unchen (Germany)Fabbietti Laura TU-M¨unchen (Germany)Faber Manfried TU-Wien (Austria)Fayfman Mark Kurchatov Institute (Russia)Filippi Alessandra INFN Torino (Italy)Friedman Eli Racah Institute of Physics (Israel)Gal Avraham Hebrew University (Israel)Gazda Daniel NPI, Rez (Czech Republic)Guaraldo Carlo LNF, INFN (Italy)Hartmann Olaf SMI Vienna (Austria)Herrmann Norbert Univ. Heidelberg (Germany)Ishiwatari Tomoichi SMI, Vienna (Austria)Ivanov Andrei TU-Wien, (Austria)Iwasaki Masahiko RIKEN (Japan)Kalantari Seyed Zafarollah Isfahan Univ. of Tech. (IUT) (Iran)Kienle Paul TU-Munich (Germany)Krejcirik Vojtech NPI, ASCR, Rez (Czech Republic)Magas Volodymyr University of Barcelona (Spain)Mares Jiri Nuclear Physics Institute, Rez (Czech Republic)MARTON Johann SMI Vienna (Austria)Outa Haruhiko RIKEN (Japan)Pasqua Antonio University of Manchester (United Kingdom)Piano Stefano INFN Trieste (Italy)Pitschmann Mario TU Vienna (Austria)Revai Janos Research Institute for Particle and Nuclear Physics (Hungary)Romero Vidal Antonio LNF, INFN (Italy)Salvini Paola INFN Pavia (Italy)Sato Masaharu Univ. of Tokyo (Japan)Scordo Alessandro LNF-INFN (Italy)Shevchenko Nina NPI Rez (Czech republic)Siebenson Johannes TU-M¨unchen (Germany)Suzuki Takatoshi Uni. of Tokyo (Japan)Vazquez Doce Oton LNF, INFN (Italy)Weise Wolfram TU Munich (Germany)Wuenschek Barbara SMI Vienna (Austria)Wycech Slawomir Soltan Institute for Nuclear Studies (Poland)Yamazaki Toshimitsu Univ. Tokyo (Japan)Zmeskal Johann SMI (Austria) onference Photosonference Photos