M. Barth

InclusiveK*+(892) andK*0(892) production inK+p interactions at 32 GeV/c

Total and semi-inclusive cross sections, longitudinal and transverse momentum distributions and spin density matrix elements of theK*+(892) andK*0(892) produced in the inclusive reactionsK+p→K*+(892)+X andK+p→K*0(892)+X at 32 GeV/c are studied in detail. The inclusive spectra of theK*(892) and their decay products are compared with pion and neutral kaon production. TheK*+(892) andK*+(892) are dominantly produced by kaon fragmentation processes. The dependence of average transverse momentum vs.x for resonances has been investigated for the first time.

Inclusive neutral kaon production in 70 GeV/c K+p interactions

Abstract The inclusive production of neutral kaons in 70 GeV/ c K + p interactions is studied with the CERN BEBC bubble chamber. The (semi-)inclusive cross sections are interpreted in terms of the various strangeness channels leading to neutral kaon production. The invariant inclusive cross section for kaon production is studied as a function of p t 2 and the Feynman variable x . The latter distributions are considered both “raw” and corrected for the presence of K 0 s resulting from K ∗ decay. They are compared with the predictions expected from the Regge-Mueller formalism, the recombination model and fragmentation models.

Charged pion production in 70 GeV/cK+p interactions

Inclusive charged pion production is studied in an exposure of BEBC, filled with hydrogen, to an incidentK+ beam of 70 GeV/c. Total cross sections for pion production and inclusive longitudinal and transverse momentum distributions of π−s and of positive particles are presented and compared with data at lower energies. Earlier evidence for scaling in the fragmentation regions is confirmed. The central region π− cross section increases proportionally topLAB−1/4; positive particles show almost no energy dependence atx=0. Particle ratios π+/π− are studied as a function ofx andy* and a comparison with 70 GeV/cK−p data is made. Analysis of structure functions for (ππ) pairs and of particle production associated with π± triggers at large |x| in the context of quark/parton models, provides qualitative evidence for the diquark-quark structure of the proton.

Inclusive hadronic fragmentation in K±p interactions at 32 GeV/c and counting rules

Abstract Longitudinal invariant structure functions E d σ d x for a number oflow p t hadronic fragments produced in K +- interactions at 32 GeV/ c are presented. Data were obtained in the Mirabelle bubble chamber. The fragmentation modes investigated are K ± → K 0 , K 0 , K ∗0,+ (890), K ∗0,− (890), ϕ, ϱ 0 , π +- , Λ, ḡL, and p → p inel , Δ ++ (1236), Λ, ḡL, π ± , K 0 , ϱ 0 . These various fragmentation spectra clearly fall into a definite hierarchy, the invariant cross sections being more suppressed at large | x | the bigger the difference between initial and final state hadron quantum numbers. Invariant cross sections in the fragmentation regions are adequately fitted by a power law Edσ / dx ∝ (1 − | x |) n as suggested by dimensional or Regge counting The values of n are in general consistent with values obtained at FNAL and ISR energies for comparable data. They are in good overall agreement with the quark counting rules as recently reformulated, and the deviations observed suggest corrections due to strange (s) and light (u, d) quark mass differences. The power laws governing the kaon valence quark structure functions behave at large x as s K V ( x ) x →+1 ∼ (1 − x ) 0.5 and ū K V (x) x→+1 ∼ (1 − x) 1.5 .

Inclusive single and double diffractive dissociations inK+p interactions at 32 GeV/c

AbstractWe study single and double inclusive diffractive production in a 32 GeV/c K+p experiment in MIRABELLE at the Serpukhov accelerator. From reactionsK+p→K++X+ andK+p→X++p we determine the total proton and kaon single diffractive dissociation cross sectionsn

Neutral strange particle production inK+p interactions at 32 GeV/c

sigma (pxrightarrow{{K^ + }}p_D ) = 0.90 pm 0.12 mb

Study of the inclusive reactions K+p → pX and K+p → pK0X at 32 GeV/c

n andn