Nuclear Physics & RIKEN Theory Seminar

In this talk, I will present our study on the azimuthal anisotropy of high p_t particles (from jets) in the relativistic heavy ion collisions, which encode the information about jet energy loss in the medium as well as the medium itself. We focus on three different models with distinctive path-length and matter-density dependence of the energy loss: L^{2}, L^{3}, and near-Tc-enhancement (NTcE). We will first show our simple estimate of jet response to the shape fluctuation of the medium (initial state fluctuation) in the central 200 AGeV Au-Au collision. Second, the MC Glauber model is applied to study different Fourier-harmonics (V_{1,2,3,,,6}) of the final high P_t hadron spectrum in the non-central collisions at both RHIC and LHC (Pb-Pb collision). We find both L^{3} and NTcE can explain V_2 at RHIC (L^{2} underestimates it by roughly 20%), while L^{2} and NTcE are successful at LHC@2.76 TeV (L^{3} overestimates it by roughly 20%). In addition, we see the consistency between our NTcE calculations for other higher harmonics and the LHC@2.76 TeV data. The predictions of these harmonics for LHC@5.5 TeV will also be presented.