Fri·Apr 14, 2017Friday·April 14, 2017

1. 01*

   Heavy flavour production in proton-lead and lead-lead collisions with LHCb

   Michael Winn🇫🇷

   The LHCb experiment offers the unique opportunity to study heavy-ion interactions in the forward region (2 <eta< 5), in a kinematic domain complementary to the other 3 large experiments at the LHC. The detector has excellent capabilities for reconstructing quarkonia and open charm states, including baryons, down to zero $p_T$. It can separate the prompt and displaced charm components. In $p$Pb collisions, both forward and backward rapidities are covered thanks to the possibility of beam reversal. Results include measurements of the nuclear modification factor and forward-backward ratio for charmonium, open charm and bottomonium states. These quantities are sensitive probes for nuclear effects in heavy flavour production. Perspectives are given with the large accumulated luminosity during the 2016 $p$Pb run at the LHC. In 2015, LHCb participated successfully for the first time in the PbPb data-taking. The status of the forward prompt J/$\psi$ nuclear modification factor measurement in lead-lead collisions is discussed.

   nucl-exhep-exNPA(2017)·5 citations
2. 02*

   A hybrid approach to relativistic heavy-ion collisions at the RHIC BES energies

   Chun Shen🇺🇸 · Gabriel Denicol🇧🇷 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Akihiko Monnai🇫🇷 · Bjoern Schenke🇺🇸

   Using a hybrid (viscous hydrodynamics + hadronic cascade) framework, we model the bulk dynamical evolution of relativistic heavy-ion collisions at Relativistic Heavy Ion Collider (RHIC) Beam Energy Scan (BES) collision energies, including the effects from non-zero net baryon current and its dissipative diffusion. This framework is in full (3+1)D, which allows us to study the non-trivial longitudinal structure and dynamics of the collision systems, for example baryon stopping and transport, as well as longitudinal fluctuations. For the first time, the quantitative effect of net-baryon diffusion on hadronic observables is addressed. Finally, we propose a dynamical initialization scheme to study the importance of the pre-equilibrium stage at the RHIC BES energies.

   ↳ nucl-thhep-phnucl-exNPA(2017)·46 citations
3. 03*

   A Detailed Study and Synthesis of Flow Observables in the IP-Glasma+MUSIC+UrQMD Framework

   Scott McDonald🇨🇦 · Chun Shen🇺🇸 · Francois Fillion-Gourdeau🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

   In this work we use the IP-Glasma+MUSIC+UrQMD framework to systematically study a wide range of hadronic flow observables at 2.76 TeV. In addition to the single particle spectra and anisotropic flow coefficients $v_n$ previously studied in \cite{1609.02958}, we consider event-plane correlations, non-linear response coefficients ${\chi }_{npq}$, and event shape engineering. Taken together, these observables provide a wealth of insight into the collective behavior of the QGP and initial state fluctuations. They shed light on flow fluctuations, flow at fixed system size but different initial geometries, as well as the non-linear hydrodynamic response to the initial state spatial eccentricities. By synthesizing this information we can gain further insight into the transport properties of the QGP as well as the fluctuation spectrum of the initial state.

   ↳ nucl-thhep-phnucl-exNPA(2017)·8 citations
4. 04*

   Pre-equilibrium Longitudinal Flow in the IP-Glasma Framework for Pb+Pb Collisions at the LHC

   Scott McDonald🇨🇦 · Chun Shen🇺🇸 · Francois Fillion-Gourdeau🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

   In this work, we debut a new implementation of IP-Glasma and quantify the pre-equilibrium longitudinal flow in the IP-Glasma framework. The saturation physics based IP-Glasma model naturally provides a non-zero initial longitudinal flow through its pre-equilibrium Yang-Mills evolution. A hybrid IP-Glasma+MUSIC+UrQMD frame- work is employed to test this new implementation against experimental data and to make further predictions about hadronic flow observables in Pb+Pb collisions at 5.02 TeV. Finally, the non-zero pre-equilibrium longitudinal flow of the IP-Glasma model is quantified, and its origin is briefly discussed.

   ↳ nucl-thhep-phnucl-exNucl.Part.Phys.Proc.(2017)·3 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.