Chiral corrections to the vector and axial couplings of quarks and baryons

TL;DR

This paper computes chiral corrections to quark and baryon couplings relevant for semileptonic transitions using a covariant approach, linking quark model parameters to baryon chiral perturbation theory predictions.

Contribution

It introduces a covariant chiral quark model calculation of semileptonic couplings up to order O(p4), connecting quark-level and baryon-level descriptions.

Findings

Chiral corrections to quark couplings are quantified.

A link between quark model parameters and baryon ChPT is established.

Results agree with model-independent ChPT predictions.

Abstract

We calculate chiral corrections to the semileptonic vector and axial quark coupling constants using a manifestly Lorentz covariant chiral quark approach up to order O(p4) in the two- and tree-flavor picture. These couplings are then used in the evaluation of the corresponding couplings which govern the semileptonic transitions between octet baryon states. In the calculation of baryon matrix elements we use a general ansatz for the spatial form of the quark wave function, without referring to a specific realization of hadronization and confinement of quarks in baryons. Matching the physical amplitudes calculated within our approach to the model-independent predictions of baryon chiral perturbation theory (ChPT) allows one to deduce the connection between our parameters and those of baryon ChPT.