Sulphur dissociation in nuclear emulsion at 3.7 and 200A GeV

Abstract

In this work, the electromagnetic dissociation (EMD) of sulphur projectile induced by two widely differing energies in nuclear emulsions is investigated. Although the percentages of EMD events of the total numbers of studied interactions are relatively small, i.e. 5.7 and 14.4% for 3.7 and 200A GeV interactions respectively, one could extract some results out of them. The emission of a proton through the 32S(γ, p)31P channel is found to be a dominant process (43.8%) at 200A GeV whereas the single alpha emission through the 32S(γ, α)28Si channel is the dominant one (34.0%) at 3.7A GeV. Multiplicity distributions of hydrogen and helium isotopes as well as the measured probabilities for the different modes of fragmentation are studied. The comparison of the present results, from electromagnetic and peripheral nuclear interactions, indicates the effective role of the different reaction mechanisms at ultra-relativistic energy (200A GeV). The experimental inclusive cross sections of different fragmentation modes produced in the EMD of 32S ions at 200A GeV were found to be in satisfactory agreement with the predictions of the combined approach of Pshenichnov et al.

Projectile fragmentation of relativistic nuclei in peripheral collisions

“…Moreover it is evident from the table that the probability of emitting more than one fragment with charge Z>2 is significantly smaller than that of emitting one projectile fragment with charge Z>2. This interpretation has also been supported in [40].…”

Yields of projectile fragments in sulphur-emulsion interactions at 3.7 A GeV

“…They indicate no change in their ionization up to a distance of at least 1cm from the interaction vertex. Their charge can be determined by the δ-ray counting method [16].…”

“…1(a, b and c). The corresponding data for different projectiles [7] ( 4 He, 12 C, 16 O, 22 Ne and 28 Si) at ∼ 3.7 A GeV are illustrated in the same figure. From this figure, the width of the MD of Z = 1 (Fig.…”

Correlations of Singly and Doubly Charged Projectile Fragments with Secondary Charged Particles Produced in 32S-Emulsion Interactions at 3.7A and 200A GeV

“…To obtain a high scanning efficiency, the pellicles were scanned under 100X magnification by doubly scanning along the beam tracks, fast in the forward direction and slow in the backward one. The details about the irradiation and scanning are reported in earlier studies [15,16]. Once an interaction is observed, the incoming track is carefully examined to ensure that it is indeed a beam track.…”