A. Valkárová

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

Factorisation breaking in diffractive dijet photoproduction at HERA

\bar p

Multiplicities and Forward-Backward Correlations in bar pp 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.

Manufacture of readout boards for a liquid argon calorimeter

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.

Neutral strange particle production in high transverse momentum π− nucleus interactions at ∼40 GeV/c

Recent experimental data on dijet cross sections in diffractive photoproduction at HERA collider are analysed with an emphasis on QCD factorisation breaking effects. The possible sources of the different conclusions of H1 and ZEUS collaborations are studied.

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

AbstractInclusiveKs0, Λ and