1992/10/27 by Elizabeth Jenkins, Michael Luke, Aneesh V. Manohar +1 · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1016/0550-3213(93)90336-n
published as Nucl.Phys.B397:84-104,1993 · 24 Pages, 7 Figures, uses harvmac
arxiv created 1992/10/27 · arxiv updated 2009/11/30
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 Σ+ → p γ decay.