⁴He(γ,d)d and ³He(γ,p)d reactions in nonlocal covariant model

¹ Institute of Electrophysics and Radiation Technologies NAS of Ukraine, 61002, Kharkiv-2, str. Chernyshevsky 28, p/o box 8812, Ukraine
² V.N. Karazin Kharkiv National University, 61022, Svoboby sq.4, Kharkiv, Ukraine

^a e-mail: kuznietsov@ukr.net

Published online: 20 March 2014

Abstract

Photonuclear reaction research is of great interest to obtain information about the structure of nuclei. The investigation of structural effects requires certain insights into the reaction mechanisms, that have to be identified on the basis of the fundamental principles of covariance and gauge invariance. The major achievement of the chosen model is the ability to reproduce the cross-section dependence using the minimal necessary set of parameters. We analyze the two-particle disintegration of ³He nuclei by photons. Our interest was raised by the fact that ³He is the simplest many-particle system which admits an exact solutions. We also consider the process ⁴He(γ, d)d. This process comes at the expense of the quadrupole absorption of γ-rays, while the dipole transition is suppressed. This property is a consequence of the isospin selection as well as the identity of the particles in the final state. Obtained results describe the energy range from threshold (20 MeV) to 140 MeV. Therefore, the model mentioned in the paper has the peculiarity to be valid not only for the low-energy regime, but also for higher energies. Present paper is devoted to determine the roles of different reaction mechanisms and to solve problems above.