On the correlation coefficient T(Ee) of the neutron beta decay, caused by the correlation structure invariant under discrete P, C and T symmetries
We analyze the correlation coefficient T(Ee), which was introduced by Ebel and Feldman (1957) [64]. The correlation coefficient T(Ee) is induced by the correlation structure (ξ→n⋅k→ν¯)(k→e⋅ξ→e)/EeEν¯, where ξ→n,e are unit spin-polarization vectors of the neutron and electron, and (Ee,ν¯,k→e,ν¯) are...
Gespeichert in:
Veröffentlicht in: | Physics letters. B 2021-05, Vol.816, p.136263, Article 136263 |
---|---|
Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | We analyze the correlation coefficient T(Ee), which was introduced by Ebel and Feldman (1957) [64]. The correlation coefficient T(Ee) is induced by the correlation structure (ξ→n⋅k→ν¯)(k→e⋅ξ→e)/EeEν¯, where ξ→n,e are unit spin-polarization vectors of the neutron and electron, and (Ee,ν¯,k→e,ν¯) are energies and 3–momenta of the electron and antineutrino. Such a correlation structure is invariant under discrete P, C and T symmetries. The correlation coefficient T(Ee), calculated to leading order in the large nucleon mass mN expansion, is equal to T(Ee)=−2gA(1+gA)/(1+3gA2)=−B0, i.e. of order |T(Ee)|∼1, where gA is the axial coupling constant. Within the Standard Model (SM) we describe the correlation coefficient T(Ee) at the level of 10−3 by taking into the radiative corrections of order O(α/π) or the outer model-independent radiative corrections, where α is the fine-structure constant, and the corrections of order O(Ee/mN), caused by weak magnetism and proton recoil. We calculate also the contributions of interactions beyond the SM, including the contributions of the second class currents. |
---|---|
ISSN: | 0370-2693 1873-2445 |
DOI: | 10.1016/j.physletb.2021.136263 |