HARD PHOTON BREMSSTRAHLUNG EFFECTS IN HYPERON SEMILEPTONIC DECAYS

An efficient Monte Carlo method for photon bremsstrahlung calculations in semileptonic decays is described. This method is useful for order- alpha radiative correction calculations, and for event generations in off-line Monte Carlo simulation programs. The order-alpha bremsstrahlu ng amplitude in hyperon semileptonic decays is given by using the Low- theorem, and the bremsstrahlung amplitude squared is calculated for un polarized decays. Numerical calculation results are presented for n -- > <pe(nu)over bar>, mu --> <e(nu)over bar(e) nu(mu)>, Sigma(-) --> <ne (nu)over bar> and Lambda --> <pe(nu)over bar> decays. The general feat ures of the Monte Carlo method might be useful for photon bremsstrahlu ng calculations in other decay and collision processes. (C) 1997 Publi shed by Elsevier Science B.V.