An estimate for the thermal photon rate from lattice QCD
Institute for Theoretical Physics, Goethe University, 60438 Frankfurt am Main, Germany
2 Dept. of Physics and Astronomy, York University, Toronto, Ontario, M3J 1P3, Canada
3 Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz, Germany
4 PRISMA Cluster of Excellence and Institute of Nuclear Physics, Johannes Gutenberg-Universität, 55128 Mainz, Germany
Published online: 26 March 2018
We estimate the production rate of photons by the quark-gluon plasma in lattice QCD. We propose a new correlation function which provides better control over the systematic uncertainty in estimating the photon production rate at photon momenta in the range πT/2 to 2πT. The relevant Euclidean vector current correlation functions are computed with Nf = 2 Wilson clover fermions in the chirally-symmetric phase. In order to estimate the photon rate, an ill-posed problem for the vector-channel spectral function must be regularized. We use both a direct model for the spectral function and a modelindependent estimate from the Backus-Gilbert method to give an estimate for the photon rate.
© The Authors, published by EDP Sciences, 2018
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