Form factors of heavy-light systems in point-form relativistic quantum mechanics: the Isgur-Wise function

TL;DR

This paper studies the electromagnetic and weak form factors of heavy-light mesons using point-form relativistic quantum mechanics, deriving an analytical Isgur-Wise function and analyzing heavy-quark symmetry breaking effects.

Contribution

It introduces a coupled channel approach within point-form relativistic quantum mechanics that respects heavy-quark symmetry and provides a simple analytical expression for the Isgur-Wise function.

Findings

Heavy-quark symmetry is preserved in this formulation.

An analytical expression for the Isgur-Wise function is derived.

Heavy-quark symmetry breaking effects are numerically analyzed.

Abstract

We investigate electromagnetic and weak form factors of heavy-light mesons in the context of point-form relativistic quantum mechanics. To this aim we treat the physical processes from which such electroweak form factors are extracted by means of a coupled channel approach which accounts for the dynamics of the intermediate gauge bosons. It is shown that heavy-quark symmetry is respected by this formulation. A simple analytical expression is obtained for the Isgur-Wise function in the heavy-quark limit. Breaking of heavy-quark symmetry due to realistic values of the heavy-quark mass are studied numerically.