M. Heiden

A measurement of p̄p and pp elastic scattering at ISR energies

We have measured the differential cross section for pp and pp elastic scattering at √s = 31, 53 and 62 GeV in the interval 0.05 < |t| < 0.85 GeV2 at the CERN ISR using the Split Field Magnet detector. At 53 and 62 GeV, for 0.17 < |t| < 0.85 GeV2 both pp and pp data show simple exponential behaviour in t; at √s = 31 GeV the data for 0.05 < |t| < 0.85 GeV2 are consistent with a change in slope near |t| = 0.15 GeV2.

A measurement of the inclusive cross section of charged pions at very high transverse momenta

Abstract The inclusive cross sections for the production of high transverse momentum π + and π − mesons in proton-proton interactions have been measured at the highest ISR energy √ s = 63 GeV and at a c.m. production angle of 50°. The cross sections for π + and π − mesons are compared as a function of transverse momentum. It is shown that the inclusive cross section of π − mesons decreases faster than the π + cross section. particle σ ( π ± )/ σ (charged particles) are presented as a function of transverse momentum.

High pT K±π± production in p-p collisions at the ISR; strangeness suppression and gluon effects

Abstract The ratios of high p T charged kaon to pion production cross sections at √ s = 45 and 62 GeV are presented. The values of the K ± π ± ratios are essentially independent of both √ s and x T = 2p T √s and are compatible with a strangeness suppression factor λ = 0.55. By contrast, the K − π − values fall with x T suggesting a gluonic origin of K − . QCD calculations agrees with the measurements.

A diquark scattering model for highp T proton production inpp collisions at the ISR

The relative yield of high transverse momentum protons measured inpp interctions at the CERN ISR is calculated in the framework of simple parton models. Whereas models based exclusively on quark and gluon scattering fail to describe the data, the hypothesis of diquark scattering provides a quantitative understanding of the measured dependences on transverse momentum, polar angle, and centre-of-mass energy. Different assumptions on diquark structure functions are tested.

Multiplicity dependence of transverse momentum spectra at ISR energies

Abstract We observe an increase of the average transverse momentum with the multiplicity of the charged particles produced in the central rapidity region of proton-proton collisions at ISR energies. The increase is smaller than that observed at the CERN proton-antiproton collider. The magnitude of the effect is the same for negative and positive particles.

Multiplicity dependence of the average transverse momentum and of the particle source size inp−p interactions at\(\sqrt s \)=62, 44 and 31 GeV

AbstractThe average transverse momentum and the size of the particle emitting source (measured via Bose-Einstein correlations) have been studied as functions of the charged particle density in the central region inp-p interactions at

The reaction Pomeron-Pomeron →π+π− and an unusual production mechanism for thef2 (1270)

\sqrt s

Charged multiplicity distributions in rapidity bins for pp collisions at\(\sqrt s = 31\), 44 and 62 GeV, 44 and 62 GeV

=62, 44 and 31 GeV. Both the average transverse momentum and the source size increase with increasing density at all three energies. This effect, very weak at