# Energy Loss of a Heavy Quark Produced in a Finite Size Medium

Abstract : We study the medium-induced energy loss $-\Delta E_0(L_p)$ suffered by a heavy quark produced at initial time in a quark-gluon plasma, and escaping the plasma after travelling the distance $L_p$. The heavy quark is treated classically, and within the same framework $-\Delta E_0(L_p)$ consistently includes: the loss from standard collisional processes, initial bremsstrahlung due to the sudden acceleration of the quark, and transition radiation. The radiative loss induced by rescatterings $-\Delta E_{rad}(L_p)$ is not included in our study. For a ultrarelativistic heavy quark with momentum $p \gsim 10 \ {\rm GeV}$, and for a finite plasma with $L_p \lsim 10 \ {\rm fm}$, the loss $-\Delta E_0(L_p)$ is strongly suppressed compared to the standard stationary regime $-\Delta E_0(L_p) \simeq -\Delta E_{coll}(L_p) \propto L_p$ valid when $L_p$ becomes large. This suppression is a consequence of the retardation affecting collisional processes - the latter cannot start at initial time when the heavy quark has not built its asymptotic proper field yet. Our results indicate that $-\Delta E_{rad}$ should be the dominant contribution to the total heavy quark energy loss, $-\Delta E_{tot} = -\Delta E_0 -\Delta E_{rad} \simeq -\Delta E_{rad}$, as indeed assumed in most of jet-quenching analyses. However they might raise some question concerning the RHIC data on large $p_{\perp}$ electron spectra.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00106181
Contributor : Dominique Girod <>
Submitted on : Friday, October 13, 2006 - 1:32:00 PM
Last modification on : Thursday, January 30, 2020 - 3:30:33 PM

### Citation

Pol-Bernard Gossiaux, S. Peigne, C. Brandt, Jörg Aichelin. Energy Loss of a Heavy Quark Produced in a Finite Size Medium. Journal of High Energy Physics, Springer, 2007, 0704, pp.012. ⟨10.1088/1126-6708/2007/04/012⟩. ⟨in2p3-00106181⟩

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