A.M. Blick

A partial wave analysis of the centrally produced

A partial wave analysis of the centrally produced K+K- and K0K0 channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found in each channel. The striking feature is the observation of peaks in the S-wave corresponding to the f0(1500) and fJ(1710) with J = 0. The D-wave shows evidence for the f2(1270)/a2(1320), the f2(1525) and the f2(2150) but there is no evidence for a statistically significant contribution in the D-wave in the 1.7 GeV mass region.A partial wave analysis of the centrally produced K+K- and K0K0 channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found in each channel. The striking feature is the observation of peaks in the S-wave corresponding to the f0(1500) and fJ(1710) with J = 0. The D-wave shows evidence for the f2(1270)/a2(1320), the f2(1525) and the f2(2150) but there is no evidence for a statistically significant contribution in the D-wave in the 1.7 GeV mass region.

K^{+}K^{-}

Abstract A study of the f 1 (1285) and f 1 (1420) produced in central pp interactions has been performed. For the first time in a single experiment the branching fractions of both mesons in all major decay modes have been determined. Both the f 1 (1285) and f 1 (1420) are consistent with being produced by double Pomeron exchange.A study of the f1(1285) and f1(1420) produced in central pp interactions has been performed. For the first time in a single experiment the branching fractions of both mesons in all major decay modes have been determined. Both the f1(1285) and f1(1420) are consistent with being produced by double Pomeron exchange.

and

A partial wave analysis of the centrally produced pi+pi- channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f0(980), f0(1300), f0(1500) and fJ(1710) with J = 0 in the the S-wave. The rho(770) is observed dominantly in the P0-wave and the f2(1270) is observed dominantly in the D0-wave. In addition, there is evidence for a broad enhancement in the D-wave below 1 GeV.A partial wave analysis of the centrally produced pi+pi- channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f0(980), f0(1300), f0(1500) and fJ(1710) with J = 0 in the the S-wave. The rho(770) is observed dominantly in the P0-wave and the f2(1270) is observed dominantly in the D0-wave. In addition, there is evidence for a broad enhancement in the D-wave below 1 GeV.A partial wave analysis of the centrally produced pi+pi- channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f0(980), f0(1300), f0(1500) and fJ(1710) with J = 0 in the the S-wave. The rho(770) is observed dominantly in the P0-wave and the f2(1270) is observed dominantly in the D0-wave. In addition, there is evidence for a broad enhancement in the D-wave below 1 GeV.

K^{0}_{s}K^{0}_{s}

The reaction pp ->pf (pi+pi-pi+pi-) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. In addition to the well known f1(1285) there is evidence for two JPC=2-+ states called the eta2(1620) and eta2(1875) and a broad scalar called the f0(2000). The production of these states as a function of the dPT kinematical filter shows the behaviour expected for qqbar states. In contrast, there is evidence for two states at 1.45 GeV and at 1.9 GeV which do not show the behaviour observed for qqbar states.Abstract The reaction pp → pf(π+ π− π+ π−)ps has been studied at 450 GeV/c in an experiment designed to search for gl states. A spin analysis has been performed and the dPT filter applied. In addition to the well know f1(1285) there is evidence for two JPC = 2−+ states called the η2(1620) and η2(1875) and a broad scalar called the f0(2000). The production of these states as a function of the dPT kinematical filter shows the behaviour expected for q q states. In contrast, there is evidence for two states at 1.45 GeV and at 1.9 GeV which do not show the behaviour observed for q q states.

systems in pp interactions at 450 GeV/c and new information on the spin of the

Abstract A study has been made of pseudoscalar mesons produced centrally in pp interactions. The results show that the η and η′ appear to have a similar production mechanism which differs from that of the π0. The production properties of the η and η′ are not consistent with what is expected from double Pomeron exchange. In addition the production mechanism for the η and η′ is such that the production cross section are greatest when the azimuthal angle between the pT vectors of the two protons is 90 degrees.A study has been made of pseudoscalar mesons produced centrally in pp interactions. The results show that the η and η appear to have a similar production mechanism which differs from that of the π. The production properties of the η and η are not consistent with what is expected from double Pomeron exchange. In addition the production mechanism for the η and η is such that the production cross section are greatest when the azimuthal angle between the pT vectors of the two protons is 90 degrees. Submitted to Physics Letters 1 LAPP-IN2P3, Annecy, France. 2 Athens University, Physics Department, Athens, Greece. 3 Bergen University, Bergen, Norway. 4 School of Physics and Astronomy, University of Birmingham, Birmingham, U.K. 5 CERN European Organization for Nuclear Research, Geneva, Switzerland. 6 IHEP, Protvino, Russia. 7 IISN, Belgium. 8 JINR, Dubna, Russia. 9 High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305, Japan. 10 Faculty of Engineering, Miyazaki University, Miyazaki, Japan. 11 RCNP, Osaka University, Osaka, Japan. 12 Oslo University, Oslo, Norway. 13 Faculty of Science, Tohoku University, Aoba-ku, Sendai 980, Japan. 14 Faculty of Science, Yamagata University, Yamagata 990, Japan.

f_{1}

The reaction pp ! pfps(K + K K + K ) in which the K + K K + K system is centrally produced has been studied at 450 GeV/c. production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the system favours J PC =2 ++ and its dPT dependence is similar to that observed for glueball candidates.The reaction pp to pfps(K+K-K+K-) in which the K+K-K+K- system is centrally produced has been studied at 450 GeV/c. Phi phi production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the phi phi system favours JPC = 2++ and its dPT dependence is similar to that observed for glueball candidates.

(1710)

Results are presented of an analysis of the reactions pp ->pf(k0k+pi-)ps and pp ->pf(K0K0pi0)ps at 450 GeV/c. Clear f1(1285) and f1(1420) signals are seen and a spin parity analysis shows that both have IG JPC=0+ 1++. The f1(1285) decays to a0(980)pi and the f1(1420) decays to K* Kbar. Both states have a similar dependence as a function of dPT consistent with what has been observed for other qqbar states. Evidence is also presented for a K*Kbar decay mode of the eta2(1620).Abstract Results are presented of an analysis of the reactions pp → pf(KS0K±π±)ps and pp → pf(KS0KS0π0)ps at 450 GeV/c. Clear f1(1285) and f1(1420) signals are seen and a spin parity analysis shows that both have IGJPC = 0+1++. The f1(1285) decays to a0(980)π and the f1(1420) decays to K ∗ K . Both states have a similar dependence as a function of dPT consistent with has been observed for other q q states. Evidence is also presented for a K ∗ K decay mode of the η2(1620).

A measurement of the branching fractions of the f1(1285) and f1(1420) produced in central pp interactions at 450 GeV/c

Abstract A study of the reactions pp → p f p s ( K + K − π + π − ) and pp → p f p s ( K + K − π + π − π 0 ) shows evidence for the K ∗ (892) K ∗ (892) and φω channels respectively. The K ∗ (892) K ∗ (892) mass spectrum shows a broad distribution with a maximum near threshold and an angular analysis shows that it is compatible with having J P =2 + . The behaviour of the cross-section as a function of centre of mass energy, and the four momentum transfer dependence, are compatible with what would be expected if the K ∗ (892) K ∗ (892) system was produced via double Pomeron exchange. The dP T behaviour of the φω channel is similar to what has been observed for all the undisputed q q states. In contrast, the dP T behaviour of the K ∗ (892) K ∗ (892) final state is similar to what has been observed for the φφ final state and for previously observed glueball candidates.A study of the reactions pp ->pfps(K+K-pi+pi-) and pp ->pfps(K+K-pi+pi-pi0) shows evidence for the K*K* and phi omega channels respectively. The K*K* mass spectrum shows a broad distribution with a maximum near threshold and an angular analysis shows that it is compatible with having JP = 2+. The behaviour of the cross-section as a function of centre of mass energy, and the four momentum transfer dependence, are compatible with what would be expected if the K*K* system was produced via double Pomeron exchange. The dPT behaviour of the phi omega channel is similar to what has been observed for all the undisputed qqbar states. In contrast, the dPT behaviour of the K*K* final state is similar to what has been observed for the phi phi final state and for previously observed glueball candidates.

A partial wave analysis of the centrally produced π+π− system in pp interactions at 450 GeV/c

The reaction pp ! pf( 000 )ps has been studied at 450 GeV/c. The 000 eective mass spectrum shows clear (547) and 2(1670) signals. Branching ratios for the (547) and 2(1670) are given as well as upper limits for the decays of the !(782), a1(1260) and a2(1320) into 3 0 .The reaction pp ->pf (pi+pi-pi0) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. The analysis confirms the previous observation that all undisputed qqbar states are suppressed at small dPT. In addition, a clear difference is observed in the production mechanism for the eta and omega.

A study of the centrally produced π+π-π+π- channel in pp interactions at 450 GeV/c

Abstract The lead tungstate (PWO) heavy crystal calorimeter is tested in a GAMS-type experiment detecting 50 000 π 0 -mesons produced in a 32.5 GeV/ c intensive π − beam of the 70 GeV IHEP accelerator. In spite of a huge beam load of the calorimeter cells (up to 10 6 π − /s), a clean π 0 → 2 γ signal is observed. The measured PWO spectrometer mass resolution is in good accordance with previous electron beam tests and GEANT calculations. A high precision of the real-time PWO spectrometer calibration, using the π 0 signal during the physics run, is achieved. The results of these very first spectrometric beam tests demonstrate a high performance of multicell PWO spectrometers in heavy-load high energy physics experiments of both fixed target and collider types.