S. Bhatnagar(Professor)Gucho, Abebe2018-06-122023-11-092018-06-122023-11-092009-06http://10.90.10.223:4000/handle/123456789/422In this work our purpose is to calculate the pion radiative decay constant using the formulation of Bethe-Salpeter equation under covariant Instantaneous Ansatz(CIA) after inclusion of both leading(LO) as well as next-to-leading(NLO) terms in the BS wave function of the pion. In this process we also calculate the pion Bethe-Salpeter Normalizer which is an extremely lengthy calculationenRADIATIVE DECAYThesis