Speaker
Lusaka Bhattacharya
(Saha Institute of Nuclear Physics)
Description
We calculate the nuclear modification factor ($R_{AA}$) of light
hadrons by taking into account the initial state momentum
anisotropy of the quark gluon plasma (QGP) expected to be formed in
relativistic heavy ion collisions.
Such an anisotropy can result from the
initial rapid longitudinal expansion of the matter.
A phenomenological model for the space time evolution of the
anisotropic QGP is used to obtain the time dependence of the
anisotropy parameter $\xi$ and the hard momentum scale, $p_{\rm hard}$.
The result is then compared with the PHENIX experimental data to
constrain the isotropization time scale, $\tau_{\rm iso}$.
It is shown that the extracted value of $\tau_{\rm iso}$ lies in the
range $0.5 \leq \tau_{\rm iso} \leq 1.5$.
The present calculation is also extended to contrast with
the recent measurement of nuclear modification factor by ALICE
collaboration at $\sqrt{s}=2.76$ TeV. It is argued that similar
values of $\tau_{\rm iso}$ are closer to the data. The sensitivity of
the results on the initial conditions has been discussed. We also present
the nuclear modification factor at LHC energies with $\sqrt{s} = 5.5$ TeV.
Primary author
Lusaka Bhattacharya
(Saha Institute of Nuclear Physics)
