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Istituto Nazionale di Fisica Nucleare – LNF, FrascatiMay , 2018. Physics at forward-rapidity in heavy-ion collisions. Xin-Nian Wang CCNU/LBNL. Three properties of sQGP. T he most perfect fluid ( h /s ~ (1 - 2)/4 p ) T he most opaque fluid to jets ( qhat /T 3 =4 - 8)
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IstitutoNazionale di FisicaNucleare–LNF, FrascatiMay , 2018 Physics at forward-rapidity in heavy-ion collisions Xin-Nian Wang CCNU/LBNL
Three properties of sQGP The most perfect fluid ( h/s ~ (1 - 2)/4p ) The most opaque fluid to jets ( qhat/T3 =4 - 8) The most vortical fluid (w/T ~ 0.001)
Relativistic hydrodynamics • a low-momentum effective theory • Inputs from first principle QCD (e.g. lattice QCD)EoSp=p(e), transport coefficients h(T), z(T) • Initial condition: parton prod. & thermalization time
CLVisc Hydrodynamic model Pang, Petersen, XNW, arXiv:1802.04449 • 3+1D viscous hydrodynamic model • Fully parallelized on GPU with OpenCL • 100x faster than comparable than on CPU • Fluctuating initial conditions from AMPT
Sounds of QGP Propagation of primordial sound waves in a rapidly expanding fireball sensitivity to viscosity and initial conditions L Pang(2016) These collective effects will be mirrored in the final hadron spectra
Transverse anisotropic flows hv/s=0.15 Pang, Petersen & XNW, arXiv:1802.04449
3+1D Hydrodynamics with 3D fluctuating initial conditions y h x x Longitudinal structure of fluctuation and anisotropic flows
Rapidity dependence of vn Consistent with the longitudinal dependence of the initial energy density and pressure Pang, Petersen & XNW, arXiv:1802.04449
Longitudinal decorrelationof vn Fluctuation and twist of the event plane Pang, Qin, Roy, XNW, Ma, Phys.Rev. C91 (2015) 044904 Pang, Petersen, Qin, Roy & XNW EPJA 52(2006) 97
Fluctuation versus rotation Wu, Pang, Qin & XNW arXiv:1805.03762v1 Decorrelation due to amplitude fluctuation is smaller versus event-plane rotation
Global Orbital Angular Momentum y z x Heavy ioncollisions: Local vorticity
Global spin polarization in A+A spin-vorticity coupling Liang & XNW, PRL 94 (2005) 102301 Bjorken scaling violation
Spin polarization in equilibrium Dirac Eq. Spin: vorticity coupling Magnetic coupling + gradient expansion Becattini & Ferroni, EJPC 52 (2007) 597, Betz, Gyulassy & Torrieri, PRC 76 (2007) 044901, Becattini, Piccinini & Rizzo, PRC 77 (2008) 024906, Beccatini, Csernai & Wang, PRC 87 (2013) 034905, Xie, Glastad & Csernai, PRC 92 (2015) 064901, Deng & Huang, arXiv 1603.06117
Consequences in A+A collisions Globally Polarized thermal dilepton, J/Y, Hyperons and vector mesons Constituent quark model Liang & XNW, PRL 94 (05) 102301 Liang & XNW, PLB 629(05)20 Gao et al, PRC 77 (08) 044902 Yang,Fang,Wang & XNW arXiv:1711.06008
Features of Global Hyperon Polarization • Hyperons & anti-hyperons are similarly polarized • PH=0 in central and increases with b • Increases with y at fixed collision energy • Increase at lower energy at fixed y y
Transverse vorticity: Toroidal structure x Toroidal structure of transverse fluid vorticity, in addition to the global net vorticity Pang, Petersen, Wang & XNW,PRL 117(2016) 192301
Transverse spin correlation Pb + Pb @ 2.76 TeV (20-30%) Pang, Petersen, Wang & XNW, PRL 117(2016) 192301
Summary: I QGP in heavy-ion collisions has interesting longitudinal structure at large rapidity Fluctuations in longitudinal direction leads to decorrelation of anisotropic flow and rotation event planes BJ scaling violation leads to larger local vorticity large lambda polarization
Jet quenching in heavy-ion collisions Parton energy loss leads to jet suppression Jet 1 q q Jet 2 Energy deposition leads to medium excitation A-A collision
Jet Quenching phenomena at RHIC STAR Preliminary Pedestal&flow subtracted
Jet Quenching phenomena at LHC Pedestal&flow subtracted
Jet transport coefficient JET Collaboration: Phys.Rev. C90 (2014) 1, 014909
Tomography with full jets Jet profile and jet yield sensitive to jet-medium interaction Less sensitive to non-perturbativehadronization Jet-induced medium excitation becomes relevant
LBT: Linear Boltzmann Transport Induced radiation jet parton Li, Liu, Ma, XNW and Zhu, PRL 106 (2010) 012301 XNW and Zhu, PRL 111 (2013) 062301 He, Luo, XNW & Zhu, PRC91 (2015) 054908; medium parton pQCD elastic and radiative processes (high-twist) Transport of medium recoil partons 3+1D hydro bulk evolution
Beyond LBT: CoLBT-hydro(Coupled Linear Boltzmann Transport hydro) • LBT for energetic partons (jet shower and recoil) • Hydrodynamic model for bulk and soft partons: CLVisc CLVisc: (3+1)D viscous hydrodynamics parallelized on GPU using OpenCL Hadronization in LBT: TAMU parton recombination model
Light and heavy quark hadron suppression PbPb@2760 GeV PbPb@5020 GeV AuAu@200 GeV Cao, Luo, Qin & XNW, PRC94 (2016) 014909
Medium response & jet energy loss Recoil partons within the jet cone reduce the net jet energy loss Diffusion wake (backreaction) reduces deplete the thermal background, if taken into account, increase the net jet Energy loss with given cone-size 0-10% 2.76 TeV R=0.4 Depend on jet cone-size R Sensitive to radial flow preliminary
Single jet suppression at LHC LBT: preliminary preliminary preliminary Weak pT dependence: initial jet spectra and pT dependence of energy loss DE Week energy dependence: increase of jet energy loss and the slope of initial spectra
Jet energy loss and g-jet asymmetry Poster: JET 18 T Luo Luo, Cao, He & XNW, arXiv:1803.06785
Z-jet quenching in Pb+Pb collisions arXiv:1804.11041
Gamma-jet profile p+p @ 2.76 TeV Pb+Pb @ 2.76 TeV preliminary
gamma-jet fragmentation function Preliminary CoLBT-hydro CMS R=0.3
Enhancement of soft hadrons PLB777(2018)86 Onset of soft hadron enhancement is at fixed pt~ 1.6 GeV
Azimuthal distribution of soft hadrons from jet-induced medium excitation PLB777(2018)86
Nuclear Modification of PDF Large uncertainty in gluon distribution in large nuclear
Flavor dependence of nuclear PDF Kulagin & Petti (KP) parameterization
W charge asymmetry h of decay lepton
Summary: II QGP in heavy-ion collisions has interesting longitudinal structure Fluctuations in longitudinal direction leads to decorrelation of anisotropic flow and rotation event planes BJ scaling violation leads to larger local vorticity large lambda polarization Jet quenching at large rapidity probes QGP in the forward direction A lot of physics opportunities in the forward direction for experiments such as LHCb