G. Jarlskog

Production of high transverse momentum particles in p-p-collisions in the central region at the CERN ISR

Abstract The inclusive production al all charged particles of transverse momentum p T between 1.5 and 4.4 GeV/ c at centre of mass angles 90° and 59.4° from p-p-collisions with √ s = 44 and 53 GeV has been measured. No strong energy dependence is observed for these transverse momenta.

Evidence for dominant vector-meson production in inelastic proton-proton collisions at 53 GeV c.m. energy

Abstract The Split Field Magnet facility at the CERN ISR has been used to measure inclusive resonance production in inelastic p-p collisions at a c.m. energy of 53 GeV. The mass spectrum of pairs of oppositely charged hadrons shows a strong correlation, which can be explained as a consequence of dominant vector meson production, accounting for more than 60% of all pions and kaons produced.

Particle composition at high transverse momenta in p-p-collisions in the central region at the CERN ISR

Abstract Preliminary measurements have been made at centre of mass energies √ s = 31 and 44 GeV of the π , K and p production ratios at 90° for p T between 2.0 and 3.5 GeV/ c . The ( K + p )/ π ratio is given down to p T = 1.4 GeV/ c . No strong energy dependence is observed for these transverse momenta.

A study of the Landau hydrodynamical model predictions for high-energy inclusive charged particle production

The predictions of the Landau hydrodynamical model are compared with the experimental results on the one-particle distributions from proton-proton collisions at the CERN ISR. n nBoth one-dimensional and three-dimensional versions of the model are considered. The parameters of the model are the velocity of sound in nuclear matter, c0, which describes the expansion and cooling of the fluid, and the break-up temperature, Tc, at which the particles emerge. The best agreement between the theoretical and experimental distributions is obtained for values of these parameters well below those from earlier investigations. The values are, however, compatible to those found in proton-nucleus investigations. The values of best agreement do, however, for the one-dimensional model, depend upon the range of phase space where the comparison is made. For the three-dimensional model, the parameter values are less sensitive to the range considered.

Description of a pair spectrometer used to study the small-angle scattering of high energy photons

Abstract A pair spectrometer has been designed to detect and measure photons in the GeV region scattered into the angular range of 1–4 mrad with respect to a well-collimated, high intensity bremsstrahlung beam. Since it was essential to know the scattering angle, the design makes a reconstruction of the conversion point possible. The momentum resolution for the experiment was ±1% and the angular resolution was ±0.25 ad.

A study of bremsstrahlung spectra from the Lund 1 GeV electron synchrotron

Abstract The shape of the bremsstrahlung spectrum from the Lund 1 GeV electron synchrotron has been investigated using a conventional pair spectrometer. The aim has been to find a description of the spectrum, especially at the high energy end, under normal running conditions.

Measurements on the Differential Cross Section of the π° - Photoproduction on Hydrogen

The differential cross section for photoproduction of π° on hydrogen has been measured in a photon energy range of 560-690 MeV and for production angles in the interval 90°-105° in the centre of mass system. The experiment detects the recoil proton and a π°-decay photon in coincidence, using optical spark chambers and a lead glass Cerenkov counter. Presented cross sections, based on 35 000 events recorded on film, are in good agreement with recent phase shift analysis.

A vidicon system for the automatic recording of spark chamber events

Abstract A vidicon system adapted for magnetic tape recording or on-line data processing has been developed. It has an error in locating a spark position of less than 1% and a two-spark resolution that is better than 1%.