Speaker
Prof.
Jiunn-Wei Chen
(National Taiwan U.)
Description
We calculate the leading order bulk viscosity \zeta of a
gluon plasma in perturbative QCD with the finite angle non-collinear
inelastic scatterings neglected by the previous calculation of Arnold,
Dogan and Moore (ADM) included. We agree with the ADM's leading order
result within errors. In contrast, our previous result on shear
viscosity \eta is smaller than that of Arnold, Moore and Yaffe (AMY)
by 10-20% at intermediate couplings due to finite angle scatterings.
Our result shows that the gluon plasma in the perturbative region is
equally conformal (with almost the same \zeta) but more perfect (with
smaller \eta) than previously obtained. We also generalize our result
to a general SU(N_c) pure gauge theory and summarize the current
status of the viscosity computations in QCD.
