Speaker
Description
We estimate the photon emission rate of the quark-gluon plasma in lattice
QCD. At leading order in the electromagnetic coupling, the photon rate is
proportional to the vector-channel spectral function evaluated on the light
cone. The determination of the spectral function from lattice correlator
data represents an ill-posed problem, which we address by introducing a Padé
ansatz for the spectral function. We measure on the lattice a newly-proposed
correlation function, suggesting physics-motivated constraints on the
parameters of the Padé ansatz. A previous analysis conducted at fixed
spatial momentum provided preliminary constraints on the value of the
photon rate. We present new results obtained by a simultaneous analysis of
data at different spatial momenta.
