C. Cochet

Particle Multiplicities in K- p Interactions at 32-GeV/c

The inclusive cross section and the average multiplicity are evaluated for most of the charged (π±, p, K±) and neutral (γ, π0, K0, K0, Λ, Λ, n) particles produced in 32 GeV/c K−p interactions; corresponding results are obtained for each charged topology separately. New results are given for the total charged multiplicity cross sections. The average longitudinal momentum of neutrals is found to be roughly equal to that of charged particles. The π+ and π− multiplicity distributions are reconstructed and compared to the π0 and to the total charged multiplicity distributions.

Vector and tensor meson production in K−p interactions at 32 GeV/c

Inclusive production of vector and tensor mesons is studied in a K−p experiment at 32 GeV/c in the MIRABELLE bubble chamber. The K∗0(890), ϱ0 and ω cross sections are comparable, about 4 mb each. The K∗0(1420 and cross sections are also comparable, about 1 mb each. The K∗o+(890), Φ, K∗o−(1420) and f cross sections beam fragmentation; ϱ production is almost forward-backward symmetric in the c.m.s. The pT production slopes of K∗o−(890) and ϱ are similar, the Φ slope is shallower. Vector and tensor mesons alone are responsible for ≅50% (≅60%) of final-state pions

Charged pion production in 32GeV/c K+p interactions

Final data on topological cross sections are presented. Inclusive single particle distributions for the reactionsK+p→ π±X at 32 GeV/c are discussed and compared with data at lower energies. Early scaling in the fragmentation regions is confirmed, while cross sections in th central region continue to rise with energy even faster than inpp interactions. Thex-andpT-dependence of the π+/π− ratio inK+p interactions is discussed and a comparison of reactionsK+p→ π±X andK−p→ π±X at 32 GeV/c is made in the context of constituent models. We also present transverse momentum distributions, show prominent seagull effects and study how they are influenced by resonance production.

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 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 production of non-strange resonances inK− p interactions at 32 GeV/c

New data on the inclusive production of the non-strange resonances ϱ0(770), ω(783), ϕ(1020) andf(1270) inK− p interactions at 32 GeV/c are presented. The inclusive production cross sections are equal to (4.32±0.72) mb, (3.7±1.4) mb, (0.65±0.10) mb and (0.91±0.35) mb respectively. Estimates of the topological cross sections are also obtained. The invariant and non-invariantx-distributions for the vector mesons ϱ0 and ϕ indicate the prevalence of forward resonance production in the c.m. system. For the tensorf-meson the rapidity andx-distributions are presented. Thet′-distributions for ϱ0, ϕ, andf have exponential slopes of 0.6±0.1 GeV−2, 1.2±0.2 GeV−2, and 0.8±0.5 GeV−2 respectively. The exponential slope ofpT2-distribution of thef-meson is equal to (2.3±0.5) GeV−2.

Neutral pion production in K+p interactions at 32 GeV/c

Abstract Inclusive and semi-inclusive distributions of γs and π 0 s in the reactions K + p → γ + X and K + p → π 0 + X at 32 GeV/ c are presented and discussed. When compared to the inclusive π − production, the π 0 cross section is found to be significantly higher in low | x | and p T regions. The data are compared with other experiments and quark fusion model predictions.

Inclusive production of strangenessS=±1 vector and tensor resonances inK−p interactions at 32 GeV/c

AbstractWe present final results on the inclusive production of then

Single and double diffractive dissociation in K−p interactions at 32 GeV/c

bar K^{*0} (890)