Inclusive production of meson resonances inK − p interactions at 110GeV/c

Total and differential cross sections ofK ^*?(890),K ^*?(890), \(\bar K^{ * 0} \) (890),K ^*0(890), \(\bar K^{ * 0} \) (1430) and? ⁰(770) produced inK ^? p interactions at 110 GeV/c are presented. The cross sections of the neutral resonances show a smooth increase with energy from 10 to 110 GeV/c incident momentum. For theK ^*+(890) and theK ^*0(890), i.e. the resonances with strangenessS=+1, this rise is quite significant: their cross sections practically double between 32 GeV/c and 110 GeV/c incidentK ^? momentum. About 50% of the neutral kaons and 30% of charged pions produced inK ^? p interactions at our energy are found to be decay products of the resonances considered.     

Two-particle azimuthal and rapidity correlations in intervals of transverse momentum in π+ p-interactions at 250 GeV/c

A multi-dimensional analysis of two-particle correlations in π⁺ p-interactions at 250 GeV/c shows interesting structure. Particularly strong positive shortrange rapidity and azimuthal correlations are observed for low-p _T like sign pairs. This observation is not reproduced by models used for comparison (FRITIOF, DPM, quark gluon (multi)string model). A possible explanation is Bose-Einstein interference not included in these models.     

Proton fragmentation into pions and pion systems inK − p interactions at 110 GeV/c and comparison to model predictions

Thex dependence of single pion and multi pion production is studied in the proton fragmentation region ofK ^? p interactions at 110 GeV/c. A recombination and a string fragmentation model have been tuned to describe the single particle distributions well and are then used to describe two and three pion production when one particle or particle system is selected in a given interval of longitudinal momentum. The string fragmentation model reproduces most of the observed distributions correctly, but fails in the case of multi π⁺ production.     

Determination of the fire-ball dimensions from second-order interference between two pions

Positive correlations are observed for pion pairs of equal charge and similar momentum vectors, produced in the reactions πp→p+5π and πp→p + 7π at 4 to 25 GeV/c. The results are consistent with being due to the second-order interference effects expected for pairs of identical bosons and lead to the determination of the average dimension of the “fire-ball’ from which the pions are emitted (〈R〉 = 1.0 ± _?0.2^+0.4 fm). Attempts are made to study the fire-ball shape by selecting pions pair emitted in various polar and azimuthal directions.     

The A dependence of fast-particle spectra in π +, K +, and p interactions with Al and Au targets at 250 GeV/c

The A dependence of charged-particle spectra in π ⁺, K ⁺, and p interactions with Al and Au targets at 250 GeV/c are presented and compared to predictions of the Quark-Gluon String Model (QGSM). It is shown that the A dependence of invariant inclusive charged-particle spectra on the Feynman variable x is very weak between Al and Au targets. The QGSM shows a larger difference between fast-particle spectra for both Al and Au targets and different beam particles. The QGSM prediction for the leading-particle spectrum over an energy range from 250 GeV to 10 TeV in pAu(Pb) reactions is in a reasonable agreement with the results of NA22 data and a cosmic-ray experiment.