We present a novel strategy to renormalize lattice operators in QCD+QED, including first order QED corrections to the non-perturbative evaluation of QCD renormalization constants. Our procedure takes systematically into account the mixed non-factorizable QCD+QED effects which were neglected in previous calculations, thus significantly reducing the systematic uncertainty on renormalization corrections. The procedure is presented here in the RI'-MOM scheme, but it can be applied to other schemes (e.g. RI-SMOM) with appropriate changes. We discuss the application of this strategy to the calculation of the leading isospin breaking corrections to the leptonic decay rates Γ(πµ2) and Γ(Kµ2), evaluated for the first time on the lattice. The precision in the matching to the W-regularization scheme is improved to O(αemαs(MW )) with respect to previous calculations. Finally, we show the updated precise result obtained for the Cabibbo-KobayashiMaskawa matrix element |Vus|.
Di Carlo, M., Martinelli, G., Giusti, D., Lubicz, V., Sachrajda, C.t., Sanfilippo, F., et al. (2020). Non-perturbative renormalization in QCD+QED and its application to weak decays. POS PROCEEDINGS OF SCIENCE, 363 [10.22323/1.363.0196].
Non-perturbative renormalization in QCD+QED and its application to weak decays
N. Tantalo
2020-11-03
Abstract
We present a novel strategy to renormalize lattice operators in QCD+QED, including first order QED corrections to the non-perturbative evaluation of QCD renormalization constants. Our procedure takes systematically into account the mixed non-factorizable QCD+QED effects which were neglected in previous calculations, thus significantly reducing the systematic uncertainty on renormalization corrections. The procedure is presented here in the RI'-MOM scheme, but it can be applied to other schemes (e.g. RI-SMOM) with appropriate changes. We discuss the application of this strategy to the calculation of the leading isospin breaking corrections to the leptonic decay rates Γ(πµ2) and Γ(Kµ2), evaluated for the first time on the lattice. The precision in the matching to the W-regularization scheme is improved to O(αemαs(MW )) with respect to previous calculations. Finally, we show the updated precise result obtained for the Cabibbo-KobayashiMaskawa matrix element |Vus|.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
