On the structure of the correlation coefficients S(E_e) and U(E_e) of the neutron beta decay
Abstract
In the standard effective V - A theory of low-energy weak interactions (i.e. in the Standard Model (SM)) we analyze the structure of the correlation coefficients S(E_e) and U(E_e), where E_e is the electron energy. These correlation coefficients were introduced to the electron-energy and angular distribution of the neutron beta decay by Ebel and Feldman ( Nucl. Phys. 4, 213 (1957)) in addition to the set of correlation coefficients proposed by Jackson et al. (Phys. Rev. 106, 517 (1957)). The correlation coefficients and are induced by simultaneous correlations of the neutron and electron spins and electron and antineutrino 3-momenta. These correlation structures do no violate discrete P, C and T symmetries. We analyze the contributions of the radiative corrections of order O(alpha/pi), taken to leading order in the large nucleon mass m_N expansion, and corrections of order O(E_e/m_N), caused by weak magnetism and proton recoil. In addition to the obtained SM corrections we calculate the contributions of interactions beyond the SM (BSM contributions) in terms of the phenomenological coupling constants of BSM interactions by Jackson et al. (Phys. Rev. 106, 517 (1957)) and the second class currents by Weinberg (Phys. Rev. 112, 1375 (1958)).
Cite
@article{arxiv.2102.02021,
title = {On the structure of the correlation coefficients S(E_e) and U(E_e) of the neutron beta decay},
author = {A. N. Ivanov and R. Höllwieser and N. I. Troitskaya and M. Wellenzohn and Ya. A. Berdnikov},
journal= {arXiv preprint arXiv:2102.02021},
year = {2021}
}
Comments
13 pages, the manuscript is revised. arXiv admin note: text overlap with arXiv:2101.01014