Electromagnetic polarizabilities of the spin-$\frac{3}{2}$ baryons in heavy baryon chiral perturbation theory

TL;DR

This paper uses Heavy Baryon Chiral Perturbation Theory to calculate electromagnetic polarizabilities of spin-3/2 baryons, revealing significant chiral corrections and the impact of magnetic transitions, with results exceeding nucleon polarizabilities.

Contribution

It provides analytical expressions for baryon polarizabilities up to order p^3, including effects of magnetic dipole transitions, for the first time in this context.

Findings

Long-range chiral corrections are substantial.

Magnetic dipole transitions can reverse polarizability signs.

Decuplet baryons have larger electric polarizabilities than nucleons.

Abstract

We employ Heavy Baryon Chiral Perturbation Theory (HB$\chi$PT), a non-relativistic effective field theory that treats baryons as heavy static sources, to calculate the electromagnetic polarizabilities of spin-3/2 baryons in two sectors: the light-flavor decuplet baryons and singly heavy sextet baryons. We derive the analytical expressions up to $\mathcal{O}\left(p^3\right)$. Our results indicate that the long-range chiral corrections provide substantial contributions to the polarizabilities. In addition, magnetic dipole (M1) transitions of the baryons can significantly affect the magnetic polarizabilities and may even reverse their signs. For the decuplet baryons, the $\Delta^+$ and $\Delta^0$ exhibit the largest electric polarizabilities. Their values, $\alpha_E(\Delta^+) = (17.5 \pm 9.5)\times 10^{-4} \, \mathrm{fm}^3$ and $\alpha_E(\Delta^0) = (17.0 \pm 9.3)\times 10^{-4} \, \mathrm{fm}^3$, significantly exceed those typically observed for nucleons. Meanwhile, the electric polarizabilities of spin-3/2 singly heavy baryons are comparable to those of their spin-1/2 partners.