Structure of the correlation coefficients S (E_{e}) and U (E_{e}) of the neutron β decay
Abstract
In the standard effective V −A theory of lowenergy 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 electronenergy and angular distribution of the neutron beta decay by Ebel and Feldman [Nucl. Phys. 4, 213 (1957), 10.1016/00295582(87)900204] in addition to the set of correlation coefficients proposed by Jackson et al. [Phys. Rev. 106, 517 (1957), 10.1103/PhysRev.106.517]. The correlation coefficients S (E_{e}) and U (E_{e}) are induced by simultaneous correlations of the neutron and electron spins and electron and antineutrino threemomenta. These correlation structures do no violate discrete P, C, and T symmetries. We analyze the contributions of the radiative corrections of order O (α /π ) , 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 radiative O (α /π ) and O (E_{e}/m_{N}) corrections we take into account the contributions of the second class currents by Weinberg [Phys. Rev. 112, 1375 (1958), 10.1103/PhysRev.112.1375]. The contributions of interactions beyond the SM (BSM) are calculated in terms of the phenomenological coupling constants of BSM interactions by Lee and Yang [Phys. Rev. 104, 254 (1956), 10.1103/PhysRev.104.254].
 Publication:

Physical Review C
 Pub Date:
 August 2021
 DOI:
 10.1103/PhysRevC.104.025503
 arXiv:
 arXiv:2102.02021
 Bibcode:
 2021PhRvC.104b5503I
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment;
 Nuclear Experiment;
 Nuclear Theory
 EPrint:
 13 pages, the manuscript is revised. arXiv admin note: text overlap with arXiv:2101.01014