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This study investigates the suppression of heavy flavors (charm and beauty) in a dynamical quantum chromodynamics (QCD) medium with a finite magnetic mass. It explores the contribution of longitudinal and transverse polarized gluons to the energy loss and addresses the heavy flavor puzzle at RHIC. The predictions for heavy flavor suppression at the LHC are also discussed.
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Heavy flavor suppression in a dynamical medium with finite magnetic mass Magdalena Djordjevic Institute of Physics Belgrade, University of Belgrade
Overview • Brief review of the dynamical energy loss • Contribution to the energy loss due to longitudinally (electric) and transversely (magnetic) polarized gluons • Introduction of finite magnetic mass • Addressing heavy hlavor puzzle at RHIC • Suppression predictions at the LHC
Heavy flavour suppression Heavy (charm and beauty, M>1 GeV) flavour suppression is considered an excellent tool to study the properties of QGP. High pt suppression is a consequence of the energy loss. Reliable computations of energy loss mechanisms are needed.
Dynamical energy loss We developed the radiative jet energy loss formalism in a finite size dynamical QCD medium. Abolishes approximation of static scatterers. We computed the jet radiative energy loss in dynamical medium of thermally distributed massless quarks and gluons. • M. D., Phys.Rev.C80:064909,2009. • M. D. and U. Heinz, Phys.Rev.Lett.101:022302,2008.
Dynamical v.s. static radiative energy loss 60% The energy loss in dynamical QCD medium is significantly larger than in static QCD medium. What is the origin of this increase?
Dynamical medium Static medium electric contribution In static medium only electric contribution from the exchanged gluon contribute to the energy loss. magnetic contribution electric contribution In dynamical medium both electric and magnetic contributions from the exchanged gluons contribute to the energy loss. M.D.,J.Phys.G39:045007,2012
Magnetic v.s. electric contribution? M.D.,J.Phys.G39:045007,2012 Electric and magnetic contributions to the energy loss are comparable in dynamical QCD medium Additional magnetic contibution is the reason for a significant increase ofthe radiative energy loss in dynamical medium.
Finite magnetic mass? The dynamical energy loss formalism is based on HTL perturbative QCD, which requires zero magnetic mass. However, different non-perturbative approaches suggest a non-zero magnetic mass at RHIC and LHC. Can magnetic mass be consistently included in the dynamical energy loss calculations? Magnetic contribution to the energy loss depends on magnetic mass. How this inclusion would modify the energy loss results?
Generalization of radiative jet energy loss to finite magnetic mass zero magnetic mass From our analysis, only this part gets modified. Finite magnetic mass: M.D. and M. Djordjevic, Phys.Lett.B709:229,2012
A simple constraint on the magnetic mass If magnetic mass is larger than electric mass, the quark jet would, overall, start to gain (instead of lose) energy in this type of plasma. An apparent violation of the second law of thermodynamics. It is impossible to observe a plasma with magnetic mass larger than electric M.D. and M. Djordjevic, Phys.Lett.B709:229,2012 Various non-perturbative approaches suggest that, at RHIC and LHC, 0.4 < μM/μE < 0.6.
Finite magnetic mass effect CHARM CHARM Finite magnetic mass reduces the energy loss in dynamical QCD medium for 25% to 50%.
Suppression at RHIC and LHC • The numerical procedure includes: • Both collisional and radiative energy loss from the newly developed (dynamical QCD medium) formalism • Magnetic mass effects • Multi-gluon fluctuations, i.e. the fact that energy loss is a distribution • Path length fluctuations, i.e. the fact that particles travel different paths in the medium. M.D.,Phys.Rev.C85:034904,2012
D and B meson suppression at 200GeV Au+Au collisions at RHIC M.D.,Phys.Rev.C85:034904,2012 FONLL initial c and b pt disctributions Momentum discributions: W – S. Wicks, W. Horowitz,M.D.,M.Gyulassy,Nucl.Phys.A784:426,2007. D – A. Dainese,Eur.Phys.J.C33:495,2004.
Pion and single electron suppressions at 200GeV Au+Au collisions at RHIC M.D.,Phys.Rev.C85:034904,2012
D and B suppression at 2.76TeV Pb+Pb collisions at LHC FONLL initial c and b pt discributions
Summary Dynamical energy loss formalism abolishes the approximation of static QCD medium. We extended the dynamical energy loss formalism to the finite magnetic mass. The extension suggests a limit on the magnetic to electric mass ratio. Dynamical QCD medium together with the finite magnetic mass was incorporated in the numerical procedure for suppression predictions. The predictions for RHIC and LHC indicate a reasonable agreement of the dynamical energy loss formalism with the available data.
Support FP7 Marie Curie International Reintegration grant L’Oreal UNESCO For Women in Science Serbia Ministry of Science and Education in Serbia