STUDY OF THE CENTRALLY PRODUCED OMEGA-RHO(0) AND OMEGA-OMEGA SYSTEMS IN PP INTERACTIONS AT 300 GEV/C

We have performed a search for vector-vector final states centrally produced in proton proton interactions at 300 GeV/c using the CERN OMEGA spectrometer. Evidence is found for omegarho0 production in the reaction pp-->p(f)(2pi+2pi-pi0)p(s) and for omegaomega production in the reaction pp-->p(f)(2pi+2pi-2pi0)p(s). However no evidence is found for omegaphi production in the reaction pp-->p(f)(K+K-pi+pi-pi0)p(s)

FURTHER STUDY OF THE E/F1(1420) MESON IN CENTRAL PRODUCTION

We have studied the reactions (pi+/p)p --> (pi+/p) (KKpiBAR)p, where the KKpiBAR system is centrally produced, at 85 GeV/c and 300 GeV/c using the CERN Omega spectrometer. A spin-parity analysis of the K(S)0K+/-pi-/+ system shows the presence of a strong J(PC)= 1++ signal which we identify as the E/f1 (1420) meson. We also find evidence for the decay E/f1 (1420)--> K(S)0K(S)0pi0 which determines the C-parity of this state to be positive. Alternative explanations of the data have been tested and ruled out. Hence we obtain the quantum numbers of the E/f1 (1420) to be I(G)(J(PC)=0+(1++)

SHAPE DISTORTIONS OF MESON RESONANCES PRODUCED IN HADRON INTERACTIONS AT P(T)GREATER-THAN-OR-EQUAL-TO-2GEV/C

We study the shape of the invariant mass spectra of several resonances produced at p(T) greater-than-or-equal-to 2.0 GeV/c and observed through two-particle final states, namely the f2(1270), K*(892), KBAR*(892), K*(1430), and KBAR*(1430) mesons. The data sample comes from pi- Be interactions at P(lab) = 150 GeV/c and 300 GeV/c which have been collected using the OMEGA spectrometer at CERN. We find that although these meson resonances have their masses and widths consistent with the corresponding world average values, their shapes are all subject to the same kind of distortion: their low-mass tail is enhanced while their high-mass tail is sharply cut. This observation indicates that meson resonances produced in the fragmentation of quarks and gluons are distorted by the same damping factor in a way which preserves their masses and lifetimes

TRANSVERSE-MOMENTUM DISTRIBUTIONS FOR MESON RESONANCES AT CENTRAL RAPIDITY AND PT-GREATER-THAN-OR-EQUAL-TO-2 GEV/C

The transverse momentum distributions for rho0(770),f2(1270), K*0(892),K*0BAR(892)and phi (1020)have been studied in the p(t) region between 2 and 4 GeV/c and central rapidity. The data analysed come from the WA77 experiment at CERN with a 300 GeV/c pi- beam incident on a Be target. These distributions are well described by the function p(t)-n with n approximately 8. A sample of simulated events from the Lund Monte Carlo in the same experimental conditions reproduces well the data

SHORT-RANGE CORRELATIONS IN HADRON PAIR PRODUCTION AT PT-GREATER-THAN-OR-EQUAL-TO-2 GEV/C

Production of oppositely charged particle pairs at large p(T) is studied, where both particles are in the central rapidity region within one unit of rapidity and nearby in azimuth. The data sample, which comes from pi- Be interactions obtained using the CERN OMEGA spectrometer, contains events with a pair of oppositely charged particles having p(T) greater-than-or-equal-to 2 GeV/c recoiling against a third one with p(T) greater-than-or-equal-to 1 GeV/c. Our data provide new information on short range correlations involving the production of the nine possible pairs made from (pi+, K+, p) and (pi-, K-, pBAR). Comparison with Lund Monte Carlo predictions is made. Apart from proton yields, the model reproduces correctly our data. The main discrepancies observed with protons can be attributed to hard scattering of diquarks from the target nucleons