Speaker
Prof.
Jouni Suhonen
(University of Jyväskylä)
Description
The value of the weak axial coupling, g$_A$, has pervasive impact on neutrino-nucleus interactions in many fields: Nuclear astrophysics, neutrino physics and particle physics. In particular, nuclear beta decays and double beta decays, as also astro-(anti)neutrino-nucleus scattering and nuclear muon capture imply effective quenched or enhanced values of g$_A$, sometimes deviating a lot from the default PCAC value g$_A$ = 1.27, valid for a free neutron. This quenching or enhancement of g$_A$ in finite nuclei stems from, e.g., deficiencies of the nuclear many-body approaches used to describe the involved nuclear structures (restrictions in single-particle model spaces and/or configuration spaces, neglect of three-body forces, etc.), interference of non-nucleonic degrees of freedom, nuclear medium effects, like meson-exchange (two-body) currents, and so on. In my talk I try to highlight these features by several different examples.
