C. Bromberg

Production of γ, Λ°, Ks° and Λ° in pp collisions at 102 GeV/c☆

Abstract We have measured cross section for γ , K S °, Λ and Λ production at 102 GeV/ c and find: σ ( γ ) = 170 ± 16 mb ., σ ( K S °) = 4.6 ± 0.5 mb ., σ ( Λ ) = 3.2 ± 0.4 mb ., and σ( Λ ) = 0.23 ± 0.10 mb. Both 〈 n π °〉 and 〈 n Ks °〉 appear to rise linearly with n - while the ratio 〈 n Ks °〉/〈 n π °〉 is approximately independent of n - . The integrated invariant cross section as a function of x as well as d σ /d y and d σ /d p T 2 are presented and compared with other data.

Inclusive and semi-inclusive pion production in pp collisions at 102 and 400 GeV/c

In this paper we present a comparative study of inclusive and semi-inclusive pion production in proton-proton collisions at 102 and 400 GeV/c, and specifically investigate the validity of various scaling hypotheses which have been proposed for particle production in high-energy collisions t. The data are from an analysis of inelastic events (~3000 events at 102 GeV/c and 42200 events at 400 GeV/c) obtained in exposures of the FNAL 30-inch bubble chamber to proton beams at the highest available accelerator momenta ~. A difficulty in the analysis of bubble chamber data at high energies is the lack of particle identification for tracks of momenta in excess od 1.2 GeV/c; below this momentum ionization estimates in the bubble chamber can be used to separate protons from pions. To correct for proton contalnination of the n + data above 1.2 GeV/c lab momentum, we have assumed that the observed cross sections for inclusive and semi-inclusive proton production, at momenta below 1.2 GeV/c, extra polate smoothly to higher momenta. The inclusive proton spectrum has been shown previously [3] to be almost independent of the scaling variable x = 2p~/x/rs for x

Inclusive and Semiinclusive Pion Production in p p Collisions at 102-GeV/c and 400-GeV/c

In this paper we present a comparative study of inclusive and semi-inclusive pion production in proton-proton collisions at 102 and 400 GeV/c, and specifically investigate the validity of various scaling hypotheses which have been proposed for particle production in high-energy collisions t. The data are from an analysis of inelastic events (~3000 events at 102 GeV/c and 42200 events at 400 GeV/c) obtained in exposures of the FNAL 30-inch bubble chamber to proton beams at the highest available accelerator momenta ~. A difficulty in the analysis of bubble chamber data at high energies is the lack of particle identification for tracks of momenta in excess od 1.2 GeV/c; below this momentum ionization estimates in the bubble chamber can be used to separate protons from pions. To correct for proton contalnination of the n + data above 1.2 GeV/c lab momentum, we have assumed that the observed cross sections for inclusive and semi-inclusive proton production, at momenta below 1.2 GeV/c, extra polate smoothly to higher momenta. The inclusive proton spectrum has been shown previously [3] to be almost independent of the scaling variable x = 2p~/x/rs for x

Production of Ξ− and Ξ+ particles in K+p collisions at 12.7 GeV/c☆

Abstract The cross section for the production of Ξ + particles in K+p interactions at 12.7 GeV/c is 10 ± 3μb; the Ξ− production cross section is 2.5 ± 1.0 μb; the upper limit on Ω− or Ω + production is 0.4 μb. The Ξ− are produced preferentially in the backward direction in the CM system while the Ξ + are produced mainly forward. The mass and lifetime of the Ξ + agree with the accepted values for the Ξ− hyperon.

PRODUCTION PROPERTIES OF LOW-MASS SYSTEMS IN pp COLLISIONS AT 102 GeV/c*

We examine in detail the properties of low-mass systems produced in the inclusive reaction p + p ~ p + anything at 102 GeV/c. We find that the internal characteristics of these low-mass nucleon-multipion systems (the anything), at fixed values of mass (M), are similar to those found for produced hadrons in high-energy collisions at fixed incident hadron energies (x/~). The resemblance between the properties of the M 2 system and the characteristics of rP collisions at s =,M 2 is particularly striking.

Inclusive π− production in π+d interactions at 24 GeV/c☆

Abstract We have studied inclusive π − production from π + d interactions at 24 GeV/ c using data obtained from the Brookhaven National Laboratory 80” bubble chamber. Distributions of longitudinal momenta in the laboratory frame and the projectile frame, of x (Feynmans scaling variable), and of rapidity in the center of mass frame are presented and compared with the corresponding distributions from the reaction π + p→ π − + anything. The effect of Fermi momentum of the nucleons has been investigated and is found to be small. We conclude that single particle inclusive π − spectra from proton and from neutron targets are very different in this energy range. The two particle correlations among negative pions in the deuteron experiment have been investigated and the results are presented.

Energy dependence of the inclusive cross section for the reaction π+ d→ π- + anything at large transverse momenta

Abstract Data are presented concerning the energy dependence of the inclusive π - production cross section in π + d interactions. A growth of the cross section at large momentum transfers is parametrized and compared to observations at the ISR.

Direct photon production at high pT in -Be and pBe collisions at 500 GeV/c

We report new measurements of inclusive direct photon production at high transverse momenta (pT) for π - and p interactions on Be at 500 Gev/r. The yields as a function of pT and rapidity (y) are in good agreement with expectations from next-to-leading-log QCD calculations employing recently extracted quark and gluon structure functions

Laboratory angular distributions for the production of charged secondaries in inelastic proton-proton collisions at 102 GeV/c☆

Lab angular distributions for the production of charged secondary particles in inelas- tic proton-proton collisions are presented. Data are separately displayed for protons and for positive and negative mesons (pions and kaons combined).