Eur. Phys. J. A (2018) 54: 61
https://doi.org/10.1140/epja/i2018-12503-9

Regular Article - Theoretical Physics

decay in the extended Nambu-Jona-Lasinio model

Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980, Dubna, Russia

^* e-mail: osipov@nu.jinr.ru

Received: 30 January 2018
Accepted: 27 March 2018
Published online: 24 April 2018

Abstract

Within the framework of the extended Nambu-Jona-Lasinio model, we calculate the matrix element of the decay, obtain the invariant mass distribution of the -system and estimate the branching ratio . The two types of contributions are considered: the contact interaction, and the axial-vector resonance exchange. The latter includes the ground state, and its first radially excited state, . The corrections caused by the - transitions are taken into account. Our estimate is in a good agreement with the latest empirical result . The distribution function obtained for the decay shows a clear signal of resonance which should be compared with future experimental data including our estimate of the decay width MeV.