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Title: Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the RI/SMOM schemes

Journal Article · · Physical Review. D, Particles, Fields, Gravitation and Cosmology
OSTI ID:1001315

Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction (RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the {ovr MS} scheme. We calculate the two-loop corrections in QCD to these matching factors as well as the three-loop mass anomalous dimensions for the RI/SMOM and RI/SMOM{sub {gamma}{mu}} schemes. These two schemes are characterized by a symmetric subtraction point. Providing the conversion factors in the two different schemes allows for a better understanding of the systematic uncertainties. The two-loop expansion coefficients of the matching factors for both schemes turn out to be small compared to the traditional RI/MOM schemes. For n{sub f} = 3 quark flavors they are about 0.6%-0.7% and 2%, respectively, of the leading order result at scales of about 2 GeV. Therefore, they will allow for a significant reduction of the systematic uncertainty of light quark mass determinations obtained through this approach. The determination of these matching factors requires the computation of amputated Green's functions with the insertions of quark bilinear operators. As a by-product of our calculation we also provide the corresponding results for the tensor operator.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Organization:
DOE - Office Of Science
DOE Contract Number:
DE-AC02-98CH10886
OSTI ID:
1001315
Report Number(s):
BNL-94273-2010-JA; PRVDAQ; KA1401020; TRN: US1100327
Journal Information:
Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 82, Issue 5; ISSN 1550-7998
Country of Publication:
United States
Language:
English