A. Burns

Spin-parity analysis of the E meson centrally produced in the reactions π+ p → π+ (K01K±K±) p and pp → p(K01K±π ±)p at 85 GeV/c

Results are presented of a spin-parity analysis on a sample of ∼ 1000 E mesons centrally produced in the reactions (π+/p) p → (π+/p) (K01K±π∓) p at 85 GeV/c. The E quantum numbers are determined to be JPC = 1++. Its decay in this channel is consistent with being 100% into K∗K + c.c. and no evidenceis seen for a δ π decay mode where δ → KK. The mass and width were determined to be M = (1425 ± 2) MeV and Γ = (62 ± 5) MeV.

A fast on-line trigger for events with multiple high transverse momentum tracks

Abstract We present a fast (30 μs) on-line trigger that selects, from 300 GeV/ c π − interactions, events with three tracks of transverse momentum larger than 0.9 GeV/ c . The essential features of this trigger are a fast read-out (300 ns per cluster) of wire chambers, situated on the chamber frame, and a digital computation of transverse momenta that can cope with multiple hits in the detectors of the trigger tracks. The digital computation is done with standard MBNIM modules.

Evidence for higher twist mechanisms in prompt ϱ0-meson production at PT > 2 GeV/c in 300 GeV/c Π−N interactions

Abstract The production of ϱ 0 mesons in hadronic interactions is investigated at high transverse momentum ( p T > 2 GeV/ c ). The data come from a sample of Π − N interactions at 300 GeV/ c obtained at the CERN OMEGA spectrometer, requiring a ϱ 0 →Π + Π − with p T (pair) > 2 GeV/ c to recoil against an opposite particle with p T (opposite) > 1 GeV/ c . The signal/(signal + background) ratio of ϱ 0 production shows an increase of 38% as x E = p T (opposite)/ p T (pair) decreases from 0.5 x E x E ⩽ 0.5. This increase is not compatible with a QCD model of parton scattering and subsequent fragmentation. It is interpreted as evidence for direct ϱ 0 production via QCD higher twist processes, in terms of which a quantitative agreement with the data is found.

A partial-wave analysis of the K−Φ system produced in the reaction K−p → K+K−K−p at 18.5 GeV/c

About 15 000 K−Φp events have been collected in the CERN Ω′ spectrometer. A partial-wave decomposition of the K−Φ system is performed. The 1+SO+ wave is dominant. The 0−P0+ and 2−P0+ waves are important and show resonant behaviour at ∼ 1.83 GeV (Γ ∼ 0.25 GeV) and ∼ 1.73 GeV (Γ ∼ 0.22 GeV) respectively. The first one can be interpreted as the second radial excitation of the kaon while the second one can be identified as one of the two L mesons.

A study of inclusive Λ, > Σ0 and Σ(1385) production in K−p interactions at 8.25 GeV/c

Abstract Inclusive Λ production has been studied in K−p interactions at 8.25 GeV/c using about 69 000 events; the total cross section is found to be 3.35 ± 0.20 mb. A comparison has been made with Σ0 and Σ(1385) inclusive production. Their influence on the inclusive Λ production is discussed. The inclusive Λ cross section and polarization is interpreted in terms of the triple-Regge model. In the target fragmentation region an effective Regge trajectory is determined which lies closer to the K than to the K∗. In the beam fragmentation region the cross-section data indicate an effective Regge trajectory which corresponds to the nucleon, while the polarization data require additional Regge exchanges to be present.

Study of theA-dependence of inclusivep,\(\bar p\),Λ and\(\bar \Lambda \) production in π±-Nucleus interactions at 30 GeV/c

AbstractWe present the first results on the production of fast (p>10 GeV/c)p,

Study of the reaction K−p→φφΛ at 8.25 GeV/c

\bar p

A partial wave analysis of thef′ region in the reaction\(K^ - p \to K\bar K\Lambda ^0 \) at 8.25 GeV/c

, Λ and