Nonleptonic charmed-baryon decays: Symmetry properties of parity-violating amplitudes

Abstract

We study the effects of pole-model-induced SU(4)-symmetry breaking in parity-violating amplitudes of Cabibbo-favored nonleptonic decays of charmed baryons. A simple technique generalizing the expressions of current algebra to the case of flavor symmetry breaking in the intermediate state is applied to sum the contributions from all intermediate excited 1/${2}^{\mathrm{\ensuremath{-}}}$ baryons of a given charm. The technique permits easy discussion of departures from current algebra for any values of \ensuremath{\Delta}c/\ensuremath{\Delta}\ensuremath{\omega} (\ensuremath{\Delta}c is the charm-noncharm mass difference, \ensuremath{\Delta}\ensuremath{\omega} the 1/${2}^{\mathrm{\ensuremath{-}}}$-1/${2}^{+}$ mass difference). We find that in the pole model the symmetry structure of parity-violating amplitudes of charmed-baryon decays into an octet baryon and an octet pseudoscalar meson consists of two pieces: (i) a term proportional to the standard current algebra expression but much smaller and of opposite sign and (ii) a term proportional to the factorization contribution, interfering with it destructively. The symmetry structure of parity-violating amplitudes for decays with vector meson production is also given. We apply the full pole model to the description of available data, compare it with the results of current algebra, and indicate places where a good discrimination between the pole model and current algebra should be possible.