Non-perturbative chiral approach to Kp --gamma Y reactions(5)

A recently developed nonperturbative chiral approach to describe the S=-1 meson-baryon reactions has been extended to investigate the near threshold $K^- p \to \gamma \Lambda, \gamma \Sigma^0$ reactions. With the parameters governed by chiral SU(3) symmetr

ij=T1√MiMj√

(2π)4Iil(ki,k;P)1

k2 µ2l+i tlj(k,kj;P).(4)

wherek’sarethemesonmomenta,Pisthetotalmomentumofthesystem,Mlandµlarerespectivelythemassesofthebaryonandmesonintheintermediatechannell.Intherest

√ofthepaper,wepresentformulaeinthecenterofmasssystemwithP=(

4f2(ki+kj),(5)

whereCijareSU(3)couplingconstantswhichcanbefoundinRef.[19],andfisthepiondecayconstant.

Thescatteringequationemployedin[19]cannowbeobtainedfromEq.(4)byusingasimpli cation:onlythepositiveenergycomponentoftheFermionpropagatoriskept.Explicitly,theruleistousethefollowingsubstitutioninevaluatinganyloop-integration:

1

E(p)up¯p u