Baryon-antibaryon dynamics in relativistic heavy-ion collisions

Abstract

The dynamics of baryon-antibaryon annihilation and reproduction ($B\bar{B}\leftrightarrow 3M$) is studied within the Parton-Hadron-String Dynamics (PHSD) transport approach for Pb+Pb and Au+Au collisions as a function of centrality from lower Super Proton Synchrotron (SPS) up to Large Hadron Collider (LHC) energies on the basis of the quark rearrangement model (QRM). At Relativistic Heavy-Ion Collider (RHIC) energies we find a small net reduction of baryon-antibaryon ($B\bar{B}$) pairs while for the LHC energy of $\sqrt{s_{NN}}$ = 2.76 GeV a small net enhancement is found relative to calculations without annihilation (and reproduction) channels. Accordingly, the sizeable difference between data and statistical calculations in Pb+Pb collisions at $\sqrt{s_{NN}}$= 2.76 TeV for proton and antiproton yields \cite{53}, where a deviation of 2.7 $\sigma$ was claimed by the ALICE Collaboration, should not be attributed to a net antiproton annihilation. This is in line with the observation that no substantial deviation between the data and statistical hadronization model (SHM) calculations is seen for antihyperons, since according to the PHSD analysis the antihyperons should be modified by the same amount as antiprotons. As the PHSD results for particle ratios are in line with the ALICE data (within error bars) this might point towards a deviation from statistical equilibrium in the hadronization (at least for protons/antiprotons). Furthermore, we find that the $B\bar{B}\leftrightarrow 3M$ reactions are more effective at lower SPS energies where a net suppression for antiprotons and antihyperons up to a factor of 2 -- 2.5 can be extracted from the PHSD calculations for central Au+Au collisions.

12 pages, 12 figures; Subsection III B added; Phys. Rev. C, in print

References in corpus (10)

• The equation of state in (2+1)-flavor QCD
• The QCD equation of state with dynamical quarks
• The QCD transition temperature: results with physical masses in the continuum limit
• The QCD Equation of State to $\mathcal{O}({\mu }_B^6)$ from Lattice QCD
• Parton transport and hadronization from the dynamical quasiparticle point of view
• Centrality dependence of proton and antiproton spectra in Pb+Pb collisions at 40A GeV and 158A GeV measured at the CERN SPS
• Chiral symmetry restoration in heavy-ion collisions at intermediate energies
• Strangeness production at SPS energies
• Impact of the initial size of spatial fluctuations on the collective flow in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV
• Baryon-antibaryon annihilation and reproduction in relativistic heavy-ion collisions

Cited by in corpus (7)

• Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) -- A Novel Microscopic N-Body Transport Approach for Heavy-Ion Collisions, Dynamical Cluster Formation and Hypernuclei Production
• "Smashing more than two": Deuteron production in relativistic heavy ion collisions via stochastic multi-particle reactions
• Open charm and dileptons from relativistic heavy-ion collisions
• The role of proton-antiproton regeneration in the late stages of heavy-ion collisions
• Constraining baryon annihilation in the hadronic phase of heavy-ion collisions via event-by-event fluctuations
• Discrepancy in low transverse momentum dileptons from relativistic heavy-ion collisions
• Impact of Baryon anti-Baryon annihilation on hyperon ($\Lambda$, $\bar{\Lambda }$) production and apparent strangeness enhancement in $\bar{\Lambda }/\bar{p}$ in heavy ion collisions at SPS energy