B --> pi and B --> K transitions in partially quenched chiral perturbation theory

TL;DR

This paper investigates B to pi and B to K transition form factors in partially quenched QCD using chiral perturbation theory and the static heavy quark limit, providing insights for lattice QCD extrapolations.

Contribution

It introduces a method for chiral extrapolation of B transition form factors in partially quenched QCD, accounting for sea and valence quark mass dependencies.

Findings

Form factors vary linearly with sea quark mass.

Dependence on valence quark mass includes standard and quenched logarithms.

Estimated uncertainty in extrapolations is within 5%.

Abstract

We study the properties of the B-->pi and B-->K transition form factors in partially quenched QCD by using the approach of partially quenched chiral perturbation theory combined with the static heavy quark limit. We show that the form factors change almost linearly when varying the value of the sea quark mass, whereas the dependence on the valence quark mass contains both the standard and chirally divergent (quenched) logarithms. A simple strategy for the chiral extrapolations in the lattice studies with Nsea=2 is suggested. It consists of the linear extrapolations from the realistically accessible quark masses, first in the sea and then in the valence quark mass. From the present approach, we estimate the uncertainty induced by such extrapolations to be within 5%.