Radiative corrections to the m(oving)NRQCD action and heavy-light operators

TL;DR

This paper develops radiative correction calculations for the moving NRQCD action and heavy-light operators, improving lattice QCD simulations of B meson decays with large recoil mesons.

Contribution

It introduces radiative corrections to the m(oving)NRQCD action and operators, utilizing automated lattice perturbation theory and high-beta simulations for efficient higher-order computations.

Findings

Radiative corrections to the m(oving)NRQCD action are computed.

Automated lattice perturbation theory enables efficient higher-order calculations.

The approach reduces discretization errors in heavy-light decay simulations.

Abstract

Rare decays of B mesons, such as B \to K^*\gamma and B\to K^{(*)}\ell^+\ell^- are loop suppressed in the Standard Model and sensitive to new physics. The final state meson in heavy-light decays at large recoil has sizeable momentum in the rest frame of the decaying meson. To reduce the resulting discretization errors we formulate the nonrelativistic heavy quark action in a moving frame. We discuss the perturbative renormalization of the leading order heavy-light operators in the resulting theory which is known as m(oving)NRQCD. We also present radiative corrections to the NRQCD action computed using automated lattice perturbation theory. By combining this technique with high-beta simulations in the weak coupling regime of the theory higher order loop corrections can be calculated very efficiently.