Regular Article –Theoretical Physics
A study of power suppressed contributions in decay
Petersburg Nuclear Physics Institute, 188300, Gatchina, Russia
* e-mail: email@example.com
Accepted: 21 December 2019
Published online: 19 February 2020
The power suppressed amplitude which describes the Pauli () coupling in the decay is calculated within the effective field theory framework. It is shown that at the leading-order approximation this contribution is factorisable and the overlap with the hadronic final state can be described by collinear matrix elements. The obtained contribution depends on the nucleon light-cone distribution amplitudes of twist-3 and twist-4. This result is used for a qualitative phenomenological analysis of existing data for decay: branching ratio and the angular distribution in the cross section . It is found that the power corrections provide a large numerical effect.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020