  We present here a possible resolution of the jet quenching parameter
$\hat{q}$ puzzle by exploring the momentum fraction $x$ and scale $Q^2$
dependence of $\hat{q}$, in addition to temperature dependence. We explore the
momentum broadening of the jet due to Glauber gluon exchange with the
quark-gluon plasma (QGP). This has led us to define the momentum fraction $x$
for the partons in the QGP. We also show here, for the first time, possible
forms of the parton distribution function (PDF) of the QGP. The QGP-PDF as
input in $\hat{q}$ has been used to fit the PHENIX and CMS data simultaneously.
We observe that the scale evolution of the QGP-PDF and the energy of the jet
are the missing ingredients responsible for the enhancement of $\hat{q}$ at the
same temperature in RHIC collisions compared to LHC collisions.

Nuclear Theory;High Energy Physics - Phenomenology