Mon·Jul 27, 2015Monday·July 27, 2015

1. 01*

   Centrality dependence of pion freeze-out radii in Pb-Pb collisions at $\sqrt{{\mathbf{s}}_{\mathbf{NN}}}$=2.76 TeV

   ALICE Collaboration

   We report on the measurement of freeze-out radii for pairs of identical-charge pions measured in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV as a function of collision centrality and the average transverse momentum of the pair $k_{\mathrm{T}}$. Three-dimensional sizes of the system (femtoscopic radii), as well as direction-averaged one-dimensional radii are extracted. The radii decrease with $k_{\mathrm{T}}$, following a power-law behavior. This is qualitatively consistent with expectations from a collectively expanding system, produced in hydrodynamic calculations. The radii also scale linearly with ${⟨\mathrm{d}{N}_{\mathrm{ch}}/\mathrm{d}\eta ⟩}^{1/3}$. This behaviour is compared to world data on femtoscopic radii in heavy-ion collisions. While the dependence is qualitatively similar to results at smaller $\sqrt{s_{\mathrm{NN}}}$, a decrease in the $R_{\mathrm{out}}/R_{\mathrm{side}}$ ratio is seen, which is in qualitative agreement with specific predictions from hydrodynamic models. The results provide further evidence for the production of a collective, strongly coupled system in heavy-ion collisions at the LHC.

   nucl-exPRC(2016)·104 citations
2. 02*

   Novel technique to extract experimental symmetry free energy information of nuclear matter

   J. Mabiala🇺🇸 · H. Zheng🇮🇹 · A. Bonasera🇺🇸 · P. Cammarata🇺🇸 · K. Hagel · L. Heilborn · Z. Kohley · L. W. May · A. B. McIntosh🇺🇸 · M. D. Youngs · A. Zarrella · S. J. Yennello🇺🇸

   A new method of accessing information on the symmetry free energy from yields of fragments produced in Fermi-energy heavy-ion collisions is proposed. Furthermore, by means of quantum fluctuation analysis techniques, correlations between extracted symmetry free-energy coefficients with temperature and density were studied. The obtained results are consistent with those of commonly used isoscaling techniques.

   nucl-exnucl-thPRC(2015)·4 citations
3. 03*

   Constraining heavy quark energy loss using $B$ and $D$ meson measurements in heavy ion collision at RHIC and LHC energies

   Kapil Saraswat🇮🇳 · Prashant Shukla🇮🇳 · Venktesh Singh🇮🇳

   In this work, we calculate energy loss of heavy quark (charm and bottom) due to elastic collisions and gluon radiation in hot/dense medium. The collisional energy loss has been obtained using QCD calculations. The radiative energy loss is calculated using reaction operator formalism and generalized dead cone approach. We rederive the energy loss expression using same assumptions as generalized dead cone approach but obtain slightly different results. We also improve the model employed to calculate path length and the system evolution. The nuclear modification factors $R_{AA}$ including shadowing and energy loss are evaluated for $B$ and $D$ mesons and are compared with the measurements in PbPb collision at $\sqrt{s_{NN}}$ = 2.76 TeV and with the D meson and Heavy flavour (HF) electrons measurements in AuAu collision at $\sqrt{s_{NN}}$ = 200 GeV. The radiative energy loss calculated by reaction operator formalism added with collisional energy loss describes the RHIC HF electron suppression in high $p_T$ range. It also describes the LHC measurement of $B$ meson suppression but overestimates the suppression of $D$ meson. The radiative energy loss from generalized dead cone approach describes the charm suppression at both RHIC as well as LHC energies and requires energy loss due to collisions to be added in order to describe the bottom suppression at LHC.

   ↳ nucl-thhep-phnucl-exNPA(2015)·23 citations
4. 04*

   Production of Charged Hadrons in Muon Deep Inelastic Scattering

   Mohammed Sultan Al-Buriahi🇪🇬 · Mohammed Tarek Hussein🇪🇬 · Mohammed Tawfik Ghoneim🇪🇬

   The production of charged hadrons, in muon Deep inelastic scattering (DIS), at light and heavy target is presented. The particles produced by the interaction with Xenon (Xe) is compared with that produced by the interaction with Deuteron (D), to obtain information on cascading process, forward-backward productions, and the rapidity distribution in different bins of the invariant mass of the interacting system W.

   ↳ hep-phnucl-exJ.Appl.Math.Phys.(2015)·1 citation

* 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.