Hopping Parameter Analysis of Leptonic and Semi-Leptonic Heavy-Light Decays

TL;DR

This paper employs the Hopping Parameter Expansion to analyze leptonic and semi-leptonic decays of D and B mesons, enabling continuous variation of pseudoscalar masses and investigation of heavy-quark limit corrections.

Contribution

It introduces the use of Hopping Parameter Expansion for detailed study of heavy-light meson decays and their form factors across a range of pseudoscalar masses.

Findings

Consistent computation of decay constants f_D and f_B.

Extraction of the Isgur-Wise function xi(v.v').

Analysis of 1/m_Q corrections to the heavy-quark limit.

Abstract

We study leptonic and semi-leptonic decays of D and B mesons. Use of the Hopping Parameter Expansion (HPE) for two-point functions allows us continuously to vary the pseudoscalar mass from below m_D up towards m_B. We compute the pseudoscalar decay constants f_D and f_B, and observe consistency with the value calculated in the static limit. {}From the measurement of three-point functions we compute the matrix element relevant to the decay \bar B -> D l \bar nu_l and extract the Isgur-Wise function xi(v.v'). The HPE enables us freely to vary the initial state pseudoscalar mass at constant v.v', and we investigate the 1/m_Q corrections to the heavy-quark limit.