A new angle on an old problem: helicity approach to neutron beta decay in the Standard Model

Groote, Stefan; Körner, Jürgen G.; Melić, Blaženka (2019) A new angle on an old problem: helicity approach to neutron beta decay in the Standard Model. European Physical Journal C: Particles and Fields, 79 (11). ISSN 1434-6044

Preview	PDF - Published Version - article Available under License Creative Commons Attribution. Download (603kB) | Preview
Preview	PDF - Accepted Version - article Available under License Creative Commons Attribution. Download (385kB) | Preview

Abstract

We elaborate on the dichotomy between the description of the semileptonic decays of heavy hadrons on the one hand and the semileptonic decays of light hadrons such as neutron β decays on the other hand. For example, almost without exception the semileptonic decays of heavy baryons are described in cascade fashion as a sequence of two two-body decays B1 → B2 + Woff−shell and Woff−shell → l+νl whereas neutron β decays are analyzed as true three-body decays n → p+e− +ν ̄e. Within the cascade approach it is possible to define a set of seven angular observables for polarized neutron β decays as well as the longitudinal, transverse and normal polarization of the decay electron. We determine the dependence of the observables on the usual vector and axial vector form factors. In order to be able to assess the importance of recoil corrections we expand the rate and the q2 averages of the observables up to NLO and NNLO in the recoil parameter δ = (Mn − Mp)/(Mn + Mp) =−3 observables that we analyze are protected from NLO recoil corrections when the second class current 0.689 · 10 contributions are set to zero.

Item Type:	Article
Uncontrolled Keywords:	neutron beta decay
Subjects:	NATURAL SCIENCES > Physics
Divisions:	Theoretical Physics Division
Depositing User:	Blaženka Melić
Date Deposited:	07 May 2020 11:58
URI:	http://fulir.irb.hr/id/eprint/5748
DOI:	10.1140/epjc/s10052-019-7453-5

Actions (login required)

View Item