Tue·Apr 28, 2015Tuesday·April 28, 2015

1. 01*

   Inclusive, prompt and non-prompt J/$\psi$ production at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV

   ALICE Collaboration

   The transverse momentum ($p_{\mathrm{T}}$) dependence of the nuclear modification factor $R_{\mathrm{AA}}$ and the centrality dependence of the average transverse momentum $⟨p_{\mathrm{T}}⟩$ for inclusive J/$\psi$ have been measured with ALICE for Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV in the e${}^{+}$e${}^{-}$ decay channel at mid-rapidity ($|y|<0.8$). The $⟨p_{\mathrm{T}}⟩$ is significantly smaller than the one observed for pp collisions at the same centre-of-mass energy. Consistently, an increase of $R_{\mathrm{AA}}$ is observed towards low $p_{\mathrm{T}}$. These observations might be indicative of a sizable contribution of charm quark coalescence to the J/$\psi$ production. Additionally, the fraction of non-prompt J/$\psi$ from beauty hadron decays, $f_{\mathrm{B}}$, has been determined in the region $1.5<p_{\mathrm{T}}<10$ GeV/c in three centrality intervals. No significant centrality dependence of $f_{\mathrm{B}}$ is observed. Finally, the $R_{\mathrm{AA}}$ of non-prompt J/$\psi$ is discussed and compared with model predictions. The nuclear modification in the region $4.5<p_{\mathrm{T}}<10$ GeV/c is found to be stronger than predicted by most models.

   nucl-exhep-exJHEP(2015)·134 citations
2. 02*

   Hydrodynamics with chiral anomaly and charge separation in relativistic heavy ion collisions

   Yi Yin🇺🇸 · Jinfeng Liao🇺🇸

   Matter with chiral fermions is microscopically described by theory with quantum anomaly and macroscopically described (at low energy) by anomalous hydrodynamics. For such systems in the presence of external magnetic field and chirality imbalance, a charge current is generated along the magnetic field direction --- a phenomenon known as the Chiral Magnetic Effect (CME). The quark-gluon plasma created in relativistic heavy ion collisions provides an (approximate) example, for which the CME predicts a charge separation perpendicular to the collisional reaction plane. Charge correlation measurements designed for the search of such signal have been done at RHIC and the LHC for which the interpretations, however, remain unclear due to contamination by background effects that are collective flow driven, theoretically poorly constrained, and experimentally hard to separate. Using anomalous (and viscous) hydrodynamic simulations, we make a first attempt at quantifying contributions to observed charge correlations from both CME and background effects in one and same framework. The implications for the search of CME are discussed.

   ↳ nucl-thhep-phhep-thnucl-exPLB(2016)·50 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.