L. Gatignon

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.

A study ofK+p elastic scattering and reactionK+p→K+pπ+π− at 70 GeV/c

AbstractResults are presented onK+p elastic scattering and on the reactionK+p→K+pπ+π− at 70 GeV/c. For the elastic channel, we measured the total ((2.29±0.04)mb) and differentialdσ/dt cross sections. The reactionK+p→K+pπ+π− has a total cross section of (470±23) μb and is shown to be dominated by diffractive dissociation processes. The contributions of the quasi-two-body channels

Inclusive photon and π0 production inK+p interactions at 70 GeV/c

K^ + p \to K*^0 (890)\Delta ^{ + + } (1,236)

Inclusive φ production in K+p interactions at 70 GeV/c

and

Slow proton andΔ++ production inK+p interactions at 70 GeV/c

K^ + p \to K*^0 (1,430)\Delta ^{ + + } (1,236)