Limiting fragmentation in oxygen-induced emulsion interactions at 14.6, 60, and 200 GeV/nucleon

Abstract

Pseudorapidity distributions of relativistic singly charged particles in oxygen-induced emulsion interactions at 14.6, 60, and 200 GeV/nucleon are studied. Limiting fragmentation behavior is observed in both the target and projectile fragmentation regions for a central as well as for a minimum-bias sample.Comparisons with the FRITIOF model reveal that the picture of fragmenting strings successfully describes the observed data. PACS numbers: 25.70.NpThe efforts at CERN (60 and 200 GeV/nucleon) and at BNL (14.6 GeV/nucleon) to accelerate heavy ions to ultrarelativistic energies in order to obtain the necessary requirements for the creation of a quark-gluon plasma state have resulted in a lot of experimental data on various projectile-target combinations. 1,2 The emulsion technique allows studies of produced charged particles and their distributions in space with higher accuracy and a larger acceptance than most of the current counter experiments, although with rather limited statistics. A great advantage with emulsions is that the same projectile-target system can be studied at the three available energies with identical detectors and with identical analysis criteria. In this Letter we will focus on pseudorapidity (77= -lntan0/2) distributions of charged particles emerging from interactions between oxygen and emulsion nuclei.In the EMU01 experiments two complementary exposure techniques were used, each having its own advantages. The technique utilizing vertically exposed emulsion chambers has been described elsewhere. 2 In this Letter we report on results obtained using conventional emulsion stacks exposed horizontally. These stacks consist of 30 BR-2-type pellicles, each of size 20x10x0.06

Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

“…In spite of this fact limiting fragmentation is found to remain valid over a wide range of energy. This asymptotic property has been observed experimentally in a variety of collision processes such as hadron-hadron, 29,196 hadron-nucleus, 29,197 and nucleus-nucleus 120,124,125,153,[198][199][200][201][202][203][204][205][206] for produced charged hadrons in fragmentation region at different energies. It can be clearly observed that this scaling fea-…”

Light Particle and Quark Chemical Potentials from Negatively to Positively Charged Particle Yield Ratios Corrected by Removing Strong and Weak Decays

“…At the stage of nuclear limiting fragmentation [45], nuclear fragments have similar multiplicity and charge distributions. At the stage of hadronic limiting fragmentation, the (pseudo)rapidity spectra of relativistic produced particles in forward (backward) rapidity region have the same or similar shape [46]. For heavy nucleus such as Au and Pb, the initial energy of hadronic limiting fragmentation is possibly about 4 GeV.…”

Characteristics of alpha projectile fragments emission in interaction of nuclei with emulsion

“…Error bar is 1 unit for all data points in case of maximum helium nucleus emission. Data points are from 4 He at 3.7 [11], 12 C at 3.7 [12], 16 O at 2.0 [13], 22 Ne at 3.5 [4], 24 Mg at 3.7 [14], 28 Si at 3.7 [4], 32 S at 2.0 [8], 40 Ar at 1.8 [15], 56 Fe at 1.8 [16], 84 Kr at 1.7 [17], 84 Kr at 0.95 [Present work], 139 La at 0.99 [18] and 197 Au at 0.99 [19].…”