V. Šimák

Single-particle inclusive spectra of charged particles in pp interactions at 22.4 GeV/c

The inclusive spectra for pp collisions at 22.4 GeV/c are investigated. We show that the transverse momentum distributions resemble those in high-energy pp interactions and discuss the influence of annihilation processes on the pT2 distributions. The invariant inclusive cross section for pions in the central region is found to be 28 ± 1 mb. A charge asymmetry is indicated by the y∗ spectrum in the central region, the asymmetry parameter having the value 0.15 ± 0.01. Finally, we estimate the upper limit of the diffraction dissociation of the beam particle to be 3.68−0.15+0.45 mb.

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.

Study of ϱ0 meson spin alignment in pp and pp interactions

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.

Charge asymmetry at large pT in inelastic pp reactions at 22.4 GeV/c

Charge asymmetry in pp reactions at 22.4 GeV/c is investigated as a function of transverse momentum in the c.m. rapidity interval |y∗| < 1. The charge asymmetries in the forward and backward directions are increasing with increasing transverse momentum. The increase seems to be present both in annihilation and non-annihilation processes.

InclusiveK s 0 , Λ and\(\bar \Lambda\)-production in\(\bar p\)p-interactions at 22.4 GeV/c

AbstractInclusiveKs0, Λ andn

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

bar Lambda

Observation of the spin alignment of the ϱ0-meson produced in ¯pp interactions at 22.4 and 5.7 GeV/c

n-production has been investigated inn