Energy and centrality dependence of deuteron and proton production inPb+Pbcollisions at relativistic energies

Abstract

The transverse mass m t distributions for deuterons and protons are measured in Pb+ Pb reactions near midrapidity and in the range 0 Ͻ m t − m Ͻ 1.0 ͑1.5͒ GeV/ c 2 for minimum bias collisions at 158A GeV and for central collisions at 40 and 80 A GeV beam energies. The rapidity density dn / dy, inverse slope parameter T and mean transverse mass ͗m t ͘ derived from m t distributions as well as the coalescence parameter B 2 are studied as a function of the incident energy and the collision centrality. The deuteron m t spectra are significantly harder than those of protons, especially in central collisions. The coalescence factor B 2 shows three systematic trends. First, it decreases strongly with increasing centrality reflecting an enlargement of the deuteron coalescence volume in central Pb+ Pb collisions. Second, it increases with m t . Finally, B 2 shows an increase with decreasing incident beam energy even within the SPS energy range. The results are discussed and compared to the predictions of models that include the collective expansion of the source created in Pb+ Pb collisions.

Particle decay from statistical thermal model in high-energy nucleus-nucleus collisions

“…Experimental results from AGS [22][23][24][25][26][27][28], SPS [29][30][31][32], and RHIC [33][34][35][36] of the most central collision are also shown in figure 2, and are found to be consistent with the results after strong decay in the thermal model within uncertainties. could be negligible due to the low multiplicity of Ω.…”

“…Energy dependence of particle ratiosp/p from the stage at primary production, after strong decay from high-mass resonance. Experimental results from SPS [29][30][31][32] and RHIC [33][34][35][36] of the most central collision are shown for comparison.…”

Production of antinuclei and hypernuclei in a relativistic Hagedorn resonance gas model

“…4 we show the energy dependence of various cluster yield ratios in the HRG model. The lightest cluster d/p ratio is found to be in remarkable agreement with the data [33,36,41]; its steep decrease with energy reflects enhanced nucleon produced from the decay of abundant light baryon resonances. At the RHIC energy, though the HRG prediction for 3 H/ 3 H ratio is consistent with the STAR data [2] (see Table I), the 3 H/ 3 He and 3 H/ 3 He are, however, underpredicted by about a factor of 2.…”

Production of light nuclei and anti-nuclei inppand Pb-Pb collisions at energies available at the CERN Large Hadron Collider

“…parameter B A and has been applied to many collision systems at various energies [6][7][8][9][10][11][12][13]. The binding energy of light nuclei is very small (around few MeV), so they can hardly remain intact during hadronic interactions, even if only quasielastic scattering during the hadronic phase with temperatures between 100 MeV and 170 MeV is considered.…”