2015/04/30 by Yu. B. Ivanov, D. Blaschke
Physics and Astronomy · #Baryon #Collision #Deconfinement #Excitation #Excitation function #Hadron #High-Energy Particle Collisions Research #Nuclear physics #Nuclear reaction #Particle physics theoretical and experimental studies #Physics #Proton #Quantum Chromodynamics and Particle Interactions #Quark #Rapidity #hep-ex #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevc.92.024916
published as Phys. Rev. C 92, 024916 (2015) · 7 pages, 4 figures, references and acknowledgement added, this paper is essentially based on arXiv:1211.2579, arXiv:1302.5766
arxiv created 2015/05/28 · openalex publication_date 2015/08/24 · arxiv updated 2015/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The impact of the experimental acceptance, i.e. transverse-momentum (pT) cutoff and limited rapidity region, on the earlier predicted irregularity in the excitation function of the baryon stopping is studied. This irregularity is a consequence of the onset of deconfinement occurring in the compression stage of a nuclear collision and manifests itself as a wiggle in the excitation function of the reduced curvature (Cy) of the net-proton rapidity distribution at midrapidity. It is demonstrated that the wiggle is a very robust signal of a first-order phase transition that survives even under conditions of a very limited acceptance. At the same time the Cy for pure hadronic and crossover transition scenarios become hardly distinguishable, if the acceptance cuts off too much of the low-pT proton spectrum and/or puts a rapidity window that is too narrow around midrapidity. It is found that the shape of the net-proton rapidity distribution near midrapidity depends on the pT cutoff. This implies that the measurements should be taken at the same acceptance for all collision energies in order to reliably conclude the presence or absence of the irregularity.