Speaker
Description
Summary
Charm quarks/antiquarks are expected to be produced at the initial fusion of the ultrarelativistic heavy-ion collisions. Just after the production, they will propagate through the quark gluon plasma and will loose energy by colliding with quarks and gluons and radiating gluons.
We have considered DGLV [1], ASW [2] and XDZR [3] formalisms for the calculation of medium-induced radiative energy loss and BT [4], PP [5] and Bjorken [6] formalisms for the calculation of collisional
energy loss. The shadowing effect is introduced by using EKS 98 parameterization for structure functions [7].
For charm quark energy loss at Pb+Pb collision @ 5.5A TeV, we see that once $p_T$ is of the order of
10 GeV or more the radiative energy loss dominates over the collisional energy loss. But
at Au+Au collision @ 200A GeV, radiative energy loss predicted by ASW formalism dominates over collisional energy loss after $p_T$=5 GeV or more. $R_{AA}$ is calculated considering PP formalism for collisional energy loss and DGLV and ASW formalisms for radiative energy loss. At forward rapidites $R_{AA}$ of
charm quarks/antiquarks shows more suppression at Pb+Pb collision @ 5.5A TeV but less suppression at Au+Au collision @ 200A GeV.
More suppression is observed when going from RHIC energy to LHC energy.
References:
[1] M. Djordjevic and M. Gyulassy, \npa {\bf 733} 265 (2004).
[2] N.Armesto, C. A. Salgado, and U. A. Wiedemann, \prd {\bf 69}, 114003 (2004).
[3] W.C.Xiang, H. T. Ding, D. C. Zhou, and D. Rohrich, \epja {\bf 25}, 75 (2005).
[4] E.Braaten and M.H.Thoma, \prd {\bf 44}, 2625 (1991).
[5] S.Peigne and A.Peshier, \prd {\bf 77}, 114017 (2008).
[6] J.D.Bjorken,FERMILAB-PUB-82/059-THY(1982).
[7] K. J. Eskola, V.J. Kolhinen, and C.A. Salgado, \epjc {\bf 9} 61 (1999).
