On mass corrections to the decay P→l+l-

The Mellin-Barnes representation is used to improve the theoretical estimate of mass corrections to the width of a light pseudoscalar meson decay into a lepton pair, P -> l(+)l(-). The full resummation of the terms ln(m(l)(2)/Lambda(2))(m(l)(2)/Lambda(2))(n) and (m(l)(2)/Lambda(2))(n) to the decay amplitude is performed, where m(l) is the lepton mass and Lambda approximate to m(rho) is the characteristic scale of the P -> gamma*gamma* form factor. The total effect of the mass corrections for the e(+)e(-) channel is negligible and, for the mu(+)mu(-) channel, its order is of a few percent.