D. Kolev

Measurement of charm production in neutrino charged-current interactions

The nuclear emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy from 1994 to 1997. In total, about 100 000 charged-current (CC) neutrino interactions with at least one identified muon were located in the emulsion target and fully reconstructed, using newly developed automated scanning systems. Charmed particles were searched for by a program recognizing particle decays. The observation of the decay in nuclear emulsion makes it possible to select a sample with very low background and minimal kinematical bias. In all, 2013 CC interactions with a charmed hadron candidate in the final state were selected and confirmed through visual inspection. The charm production rate induced by neutrinos relative to the CC cross-section is measured to be σ(νμN→μ−CX)/σ(CC)=(5.75 ± 0.32(stat)±0.30(syst))%. The charm production cross-section as a function of neutrino energy is also obtained. The results are in good agreement with previous measurements. The charm-quark hadronization produces the following charmed hadrons with relative fractions (in %): fD0=43.7±4.5, fΛc+=19.2±4.2, fD+=25.3±4.2 and fDs+=11.8±4.7.

A convenient method for experimental determination of yields and isomeric ratios in photonuclear reactions measured by the activation technique

Abstract A generalized exact formula is derived for a determination of the experimental isomeric ratio in any incident particle activation. For the particular case, when the activity of the ground state results from the simultaneous decay of both states and can be conveniently measured, the appropriate modification of this formula is evaluated and applied to six photonuclear reactions induced by 43 MeV bremsstrahlung. The experimental isomeric yield ratios of (γ, 3n) 110m,g In; (γ, p) (γ, pn), (γ, 2n2p) 117m,g In; (γ, n) 164m,g Ho and (γ, 3n) 162m,g Ho are deduced.

Large-angle production of charged pions with 3-12.9 GeV/c incident protons on nuclear targets

M.G. Catanesi, E. Radicioni, R. Edgecock, M. Ellis, ∗ F.J.P. Soler, C. Gößling, S. Bunyatov, A. Krasnoperov, B. Popov, † V. Serdiouk, V. Tereschenko, E. Di Capua, G. Vidal–Sitjes, ‡ A. Artamonov, § S. Giani, S. Gilardoni, P. Gorbunov, § A. Grant, A. Grossheim, ¶ A. Ivanchenko, ∗∗ V. Ivanchenko, †† A. Kayis-Topaksu, ‡‡ J. Panman, I. Papadopoulos, E. Tcherniaev, I. Tsukerman, § R. Veenhof, C. Wiebusch, §§ P. Zucchelli, ¶¶ A. Blondel, S. Borghi, M.C. Morone, ∗∗∗ G. Prior, † † † R. Schroeter, C. Meurer, U. Gastaldi, G. B. Mills, ‡ ‡ ‡ J.S. Graulich, §§§ G. Grégoire, M. Bonesini, ¶¶¶ F. Ferri, M. Kirsanov, A. Bagulya, V. Grichine, N. Polukhina, V. Palladino, L. Coney, ‡ ‡ ‡ D. Schmitz, ‡ ‡ ‡ G. Barr, A. De Santo, F. Bobisut, D. Gibin, A. Guglielmi, M. Mezzetto, J. Dumarchez, U. Dore, D. Orestano, F. Pastore, A. Tonazzo, L. Tortora, C. Booth, L. Howlett, G. Skoro, M. Bogomilov, M. Chizhov, D. Kolev, R. Tsenov, S. Piperov, P. Temnikov, M. Apollonio, P. Chimenti, G. Giannini, J. Burguet–Castell, A. Cervera–Villanueva, J.J. Gómez–Cadenas, J. Mart́ın–Albo, P. Novella, M. Sorel, and A. Tornero (HARP Collaboration)

High resolution study of the Λp final state interaction in the reaction p+p→K++(Λp)

The reaction pp ! K + + (�p) was measured at Tp = 1.953 GeV and � = 0 ◦ with a high missing mass resolution in order to study thep final state interaction. The large final state enhancement near thep threshold can be described using the stan- dard Jost-function approach. The singlet and triplet scattering lengths and effective ranges are deduced by fitting simultaneously thep invariant mass spectrum and the total cross section data of the freep scattering.

Simultaneous measurements of the p+d→(A=3)+π reactions

A stack of annular detectors made of high purity germanium was used to measure simultaneously

Measurement of the production cross-sections of pi(+/-) in p-C and pi(+/-)-C interactions at 12 GeV/c

pd\to {^3H} \pi^+

Magnetic spectrometer Big Karl for studies of meson production reactions

and

Cross section and tensor analysing power of the dd→ηα reaction near threshold

pd\to {^3He} \pi^0

Large-angle production of charged pions with incident pion beams on nuclear targets

differential cross sections at beam momenta of 750 MeV/c, 800 MeV/c, and 850 MeV/c over a large angular range. The extracted total cross sections for the

Forward production of charged pions with incident protons on nuclear targets at the CERN Proton Synchrotron

pd\to {^3He} \pi^0