Z. Zlatanov

Inclusive ϱ0 production in pp interactions at 22.4 GeV/c

Abstract Inclusive ϱ 0 production has been investigated in p p reactions at 22.4 GeV/ c . The total cross section for ϱ 0 production is 8.1 ± 2.0 mb. The average ϱ 0 s per event is 0.17 ± 0.03. The average transverse momentum, as obtained by extrapolation of a fitted simple exponential to the p T 2 distribution, is 0.52 ± 0.12 GeV/ c . The Feynman x and c.m. rapidity distributions show ϱ 0 to be “centrally” produced.

Experimental verification of the dual unitarization scheme

Abstract The connection between particle production in antiproton-proton annihilation and non-diffractive proton-proton processes is discussed in the framework of the dual unitarization scheme. We calculate relative multiplicity moments for antiproton-proton annihilation using the moments of non-diffractive proton-proton interactions and find good agreement with experimental annihilation data.

Observation of the dependence of the interference effect of identical pions on pion pair velocity in inclusive ¯pp-interactions at 22·4 GeV/c

The Bose-Einstein interference effect is studied using 7333 events of ¯pp-interactions withnch≧6 at 22·4 GeV/c. An essential dependence of the strength of this effect on the pion pair velocity is observed. An indication is obtained that processes with essentially different time characteristics (τ<1 fm and τ>2 fm) contribute to ¯pp-interactions at 22·4 GeV/c. The interpretation based on abundant resonance production in high energy collisions is discussed.

Inelastic\(\bar p\)p interactions at 22.4 GeV/c compared withe+e− annihilation into hadrons

AbstractThe 22.4 GeV/c

Study of ϱ0 meson spin alignment in pp and pp interactions

\bar p

Inclusive rho0 Production in anti-p p Interactions at 22.4-GeV/c

p interactions with the leading particle and the slow proton subtracted are used as data on soft processes. Considerable similarity between them and hard processes, such ase+e− annihilation into hadrons, is found by means of studying charged multiplicities, KNO scaling and longitudinal as well as transverse spectra.

Multiplicities and Forward-Backward Correlations in bar pp Interactions at 22.4 GeV/c

New results on the inclusive and semi-inclusive production of π+ mesons and protons in the whole phase space are given for about 2.2 · 104 inelastic pp interactions at 22.4 GeV/c. A method of statistical separation for spectra of particles of the same charge which are produced in CP-symmetrical reactions is discussed in detail. Experimental data are compared with quark-parton model predictions.

Differences between Annihilation and Nonannihilation Characteristics of p̄-p-Interactions at 22.4 GeV/c

The ϱ0 meson spin alignment is studied inclusively in all inelastic and in some nonannihilation channels of pp interactions at 22.4 and 12 GeV/c, in the reaction pp → 2π+ 2π− + neutrals at 5.7 GeV/c and in pp interactions at 24 GeV/c. Its dependence on multiplicity, the ϱ0 meson transverse momentum p⊥ and the Feynman variable x is investigated. The method of the inclusive analysis is checked with the help of Monte Carlo events. An essential ϱ0 meson spin alignment, manifesting itself most clearly in the transversity frame, is observed in pp interactions; the values of the probability ϱ00T of the zero ϱ0 spin projection on the normal to the production plane are 0.51 ± 0.06, 0.53 ± 0.04 and 0.55 ± 0.04 for the above pp reactions, respectively. A significant increase of ϱ00T with p⊥ and only a weak dependence of ϱ00T on x are obtained for pp data at 5.7 and 12 GeV/c. The ϱ meson spin alignment is also observed in pp nonannihilation channels at 12 GeV/c (ϱ00T = 0.65 ± 0.12) while no substantial effect is seen in pp interactions (ϱ00T ≈ 13 in any frame). The results are compared with other polarization data and discussed in terms of Regge phenomenology and a quark-parton model incorporating spin-orbit interaction with the confining field.