Effect of gluon condensate on jet quenching parameter and drag force

Abstract

Using the AdS/CFT duality, we study the jet quenching parameter and drag force in a deformed AdS background with backreaction due to the gluon condensate. It is shown that the two quantities both decrease as the value of the gluon condensate decreases in the deconfined phase. In addition, near the critical temperature T c of the QCD deconfinement transition, the gluon condensate has a stronger effect on the drag force than the jet quenching parameter. referee for his/her valuable comments and helpful advice.

Effect of gluon condensate on light quark energy loss

“…For both cases, it is shown that increasing the gluon condensate leads to increasing the energy loss. Also, this effect is more pronounced at low temperature, in accord with the findings of the drag force and jet quenching parameter [27].…”

“…From these figures, one sees that at fixed T , the ratio increases as c increases, indicating that the inclusion of the gluon condensate increases the energy loss. Moreover, one finds that, as T increases, the slope of the curve decreases, implying that c has a stronger effect on the energy loss at low temperature, in agreement with the analysis of the stopping distance, and consistent with the findings of the drag force and jet quenching parameter [27].…”

“…1, we plot x/x 0 as a function of c with fixed T , where x 0 = x| c=0 . From these figures, one sees that, at fixed T , x/x 0 decreases as c increases, which means that the inclusion of the gluon condensate decreases the stopping distance, thus enhancing the energy loss, in agreement with the findings of the jet quenching parameter and drag force [27]. Moreover, by comparing the three curves, one finds that the higher the temperature, the smaller the slope, indicating that the gluon condensate has a stronger effect on the stopping distance (or energy loss) at low temperature, in accord with [27].…”

“…First, to compare with the implications of the experimental data, we choose T to be not far above the QCD phase transition (here we set T c = 170MeV [33]). Also, we take 0 ≤ c ≤ 0.9GeV 4 and φ 0 = 0, as follows from [26,27].…”

“…For instance, the effect of the gluon condensate on the heavy quark potential was discussed in [26] and it was shown that the potential becomes deeper as the value of the gluon condensate decreases in the deconfined phase, implying that the heavy quarkonium mass drops above the deconfinement transition. Also, the gluon condensate dependence of the jet quenching parameter and drag force was analyzed in [27] and it was found that the two quantities both decrease as the gluon condensate decreases in the deconfined phase, indicating that the energy loss decreases near T c . In the present work, we want to see whether the gluon condensate has the same effect on the energy loss of light quarks as with heavy quarks, and our conclusion is affirmative.…”