2015/12/22 by Bastian B. Brandt, Anthony Francis, Benjamin Jaeger +1 · 1 citation
Physics and Astronomy · #hep-lat #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.93.054510
published as Phys. Rev. D 93, 054510 (2016) · 28 pages, 6 figures
arxiv created 2015/12/22 · arxiv updated 2016/04/06
We compute and analyze correlation functions in the isovector vector channel at vanishing spatial momentum across the deconfinement phase transition in lattice QCD. The simulations are carried out at temperatures T/Tc=0.156, 0.8, 1.0, 1.25 and 1.67 with Tc≃203MeV for two flavors of Wilson-Clover fermions with a zero-temperature pion mass of ≃270MeV. Exploiting exact sum rules and applying a phenomenologically motivated ansatz allows us to determine the spectral function ρ(ω,T) via a fit to the lattice correlation function data. From these results we estimate the electrical conductivity across the deconfinement phase transition via a Kubo formula and find evidence for the dissociation of the ρ meson by resolving its spectral weight at the available temperatures. We also apply the Backus-Gilbert method as a model-independent approach to this problem. At any given frequency, it yields a local weighted average of the true spectral function. We use this method to compare kinetic theory predictions and previously published phenomenological spectral functions to our lattice study.