Weak Radiative Hyperon Decays in Chiral Perturbation Theory

Abstract

The parity-conserving $a$ and parity-violating $b$ amplitudes for weak radiative hyperon decay are studied using chiral perturbation theory. The imaginary parts of $a$ and $b$ are computed using unitarity. The real part of $b$ is dominated by a one-loop infrared divergent graph which is computed. The real part of $a$ has a large theoretical uncertainty and cannot be calculated reliably. Counterterms for the $a$ and $b$ amplitudes are classified using $CPS$ symmetry. The experimental values for decay widths and asymmetries are consistent with theory, with the exception of the asymmetry parameter for the ${\Sigma }^{+}\to p\gamma$ decay.

24 Pages, 7 Figures, uses harvmac

Cited by in corpus (15)

• Chiral perturbation theory
• Chiral Perturbation Theory
• Recent Developments in Chiral Perturbation Theory
• Hyperons in Two Flavor Chiral Perturbation Theory
• Resonances in radiative hyperon decays
• The Decay Sigma^+ -> p l^+ l^- within the Standard Model
• New physics in $s\to d$ semileptonic transitions: rare hyperon vs. kaon decays
• Constraints on $s\to d\gamma$ from Radiative Hyperon and Kaon Decays
• Hyperon Weak Radiative Decay
• Heavy-baryon chiral perturbation theory and reparametrization invariance
• Hyperon weak radiative decays in chiral perturbation theory
• Prospects for a lattice calculation of the rare decay ${\Sigma }^{+}\to p{\ell }^{+}{\ell }^{-}$
• Weak Radiative Decays of Hyperons and of Charm and Beauty Baryons
• Chiral extrapolation of lattice data for the hyperfine splittings of heavy mesons
• Weak radiative hyperon decays