Fri·Apr 10, 2020Friday·April 10, 2020

1. 01*

   Feeddown contributions from unstable nuclei in relativistic heavy-ion collisions

   Volodymyr Vovchenko🇩🇪 · Benjamin Dönigus🇩🇪 · Behruz Kardan🇩🇪 · Manuel Lorenz🇩🇪 · Horst Stoecker🇩🇪

   We estimate the feeddown contributions from decays of unstable $A=4$ and $A=5$ nuclei to the final yields of protons, deuterons, tritons, ${}^3$He, and ${}^4$He produced in relativistic heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}>2.4$ GeV, using the statistical model. The feeddown contribution effects do not exceed 5% at LHC and top RHIC energies due to the large penalty factors involved, but are substantial at intermediate collision energies. We observe large feeddown contributions for tritons, ${}^3$He, and ${}^4$He at $\sqrt{s_{\mathrm{NN}}}\lesssim 10$ GeV, where they may account for as much as 70% of the final yield at the lower end of the collision energies considered. Sizable ($>10$%) effects for deuteron yields are observed at $\sqrt{s_{\mathrm{NN}}}\lesssim 4$ GeV. The results suggest that the excited nuclei feeddown cannot be neglected in the ongoing and future analysis of light nuclei production at intermediate collision energies, including HADES and CBM experiments at FAIR, NICA at JINR, RHIC beam energy scan and fixed-target programmes, and NA61/SHINE at CERN. We further show that the freeze-out curve in the $T$-${\mu }_B$ plane itself is affected significantly by the light nuclei at high baryochemical potential.

   ↳ nucl-thhep-phnucl-exPLB(2020)·37 citations
2. 02*

   Chiral Magnetic Effect in Isobar Collisions from Stochastic Hydrodynamics

   Gui-Rong Liang🇨🇳 · Jinfeng Liao🇺🇸 · Shu Lin🇨🇳 · Li Yan🇨🇳 · Miao Li🇨🇳

   We study chiral magnetic effect in collisions of AuAu, RuRu and ZrZr at s = 200GeV. The axial charge evolution is modeled with stochastic hydrodynamics and geometrical quantities are calculated with Monte Carlo Glauber model. By adjusting the relaxation time of magnetic field, we find our results in good agreement with background subtracted data for AuAu collisions at the same energy. We also make prediction for RuRu and ZrZr collisions. We find a weak centrality dependence of initial chiral imbalance, which implies the centrality dependence of chiral magnetic effect signal comes mainly from those of magnetic field and volume factor. Our results also show an unexpected dependence on system size: while the system of AuAu has larger chiral imbalance and magnetic field, it turns out to have smaller signal for chiral magnetic effect due to the larger volume suppression factor.

   ↳ nucl-thnucl-exCPC(2020)·14 citations
3. 03*

   Freeze-out and thermalization in relativistic heavy ion collisions

   Sourendu Gupta🇮🇳 · Debasish Mallick🇮🇳 · Dipak Kumar Mishra🇮🇳 · Bedangadas Mohanty🇮🇳 · Nu Xu🇨🇳

   High energy heavy-ion collisions in laboratory produce a form of matter that can test Quantum Chromodynamics (QCD), the theory of strong interactions, at high temperatures. One of the exciting possibilities is the existence of thermodynamically distinct states of QCD, particularly a phase of de-confined quarks and gluons. An important step in establishing this new state of QCD is to demonstrate that the system has attained thermal equilibrium. We present a test of thermal equilibrium by checking that the mean hadron yields produced in the small impact parameter collisions as well as grand canonical fluctuations of conserved quantities give consistent temperature and baryon chemical potential for the last scattering surface. This consistency for moments up to third order of the net-baryon number, charge, and strangeness is a key step in the proof that the QCD matter produced in heavy-ion collision attains thermal equilibrium. It is a clear indication for the first time, using fluctuation observables, that a femto-scale system attains thermalization. The study also indicates that the relaxation time scales for the system are comparable to or smaller than the life time of the fireball.

   ↳ hep-phnucl-exnucl-th15 citations
4. 04*

   $Z$ plus jets production via double parton scattering in $pA$ collisions at the LHC

   B. Blok🇮🇱 · F. A. Ceccopieri (Technion)🇮🇱

   We present results on Zjj production via double parton scattering in pA collisions at the LHC. We perform the analysis at leading and next-leading order accuracy with different sets of cuts on jet transverse momenta and accounting for the single parton scattering background. By exploiting the experimental capability to measure the centrality dependence of the cross section, we discuss the feasibility of DPS observation in already collected data at the LHC and in future runs.

   ↳ hep-phhep-exnucl-exnucl-thEPJC(2020)·6 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.