Non-perturbative calculation of Z_m using Asqtad fermions

Understand

We report progress on a non-perturbative calculation of the light quark mass renormalization factor Z_m, using dynamical Asqtad fermions.

• This quantity is used to determine the light quark masses in the conventional MS-bar scheme.
• Such a non-perturbative determination of Z_m removes uncertainties due to truncation of its perturbative expansion, currently known to two loops.
• These calculations have been carried out using publicly available MILC lattices with spacings of approximately 0.125 and 0.09 fm.