A. Kernan

Experimental observation of a copious yield of electrons with small transverse momenta in pp collisions at high energies

Abstract Inclusive electron and positron emission have been observed for θcm = 30° and s = 2800 GeV2 at the CERN Intersecting Storage Rings (ISR). Over the transverse momentum interval 0.2 GeV/c

Production of nucleon resonances by single diffraction dissociation at the CERN ISR

The single diffraction dissociation process pp → (pπ+π−)p has been studied at the CERN ISR at √s = 45 GeV and 0.1 < −t < 0.6 GeV2. The reaction is dominated by nucleon resonance production: pp → pN (1520) and pp → pN(1688) with cross-sections (0.25 ± 0.08) mb and (0.56 ± 0.19) mb respectively.

Evidence for double Pomeron exchange at the CERN ISR

Abstract We have observed events at the CERN Intersecting Storage Rings (ISR) which are consistent with the double Pomeron exchange process p + p → p + X + p, where X represents a system of particles in the central region of the rapidity distribution separated by at least two units from the outgoing protons in the forward directions. The observed low charge multiplicity of the central cluster X indicates that this process is dominated by the formation of a low-mass system in the central region. In particular, we find that the differential cross-section for the process p + p → p + h + + h - + p, where h represents a charged particle, shows no correlation between t A and t B and has an exponential slope of 9.9 ± 1.8 GeV −2 independent of energy. The cross-section for this process is found to be approximately 20 μb over the ISR energy range.

Diffraction dissociation in the reaction p+p→Λ°+K++p at the CERN ISR

The exclusive reaction pp→Λ°K+p has been studied at 0.1<−tpp<0.6 GeV2 and energies √s=45 GeV and 53 GeV at the CERN ISR. Diffractive excitation p→Λ°K+ occurs predominantly in the mass range M(Λ°K+)≈2.1 GeV and peaks at 1.7 GeV. The cross section for pp→Λ°K+p is 10±3μb for M(Λ°K+)<2.5 GeV, and the tpp dependence is exp (bt) with b=7.0±0.5 GeV−2.

Double diffraction dissociation and test of pomeron factorization at the CERN ISR

Abstract We report the observation of double diffraction dissociation in the process p + p → (p π + π − ) + X at √ s of 45 GeV and momentum transfer in the − t range 0.15−0.53 GeV 2 at the CERN ISR. The relative rates for elastic, single and double dissociation reactions measured here are found to agree with the prediction of Pomeron factorization.