6533b828fe1ef96bd128794d
RESEARCH PRODUCT
Mesonic enhancement of the weak axial charge and its effect on the half-lives and spectral shapes of first-forbidden J+↔J− decays
Joel KostensaloJouni Suhonensubject
Coupling constantPhysicsNuclear and High Energy PhysicsSpectral shape analysista114010308 nuclear & particles physicsSpectrum (functional analysis)forbidden beta decaysNuclear shell modelCharge (physics)01 natural scienceslcsh:QC1-999nuclear medium effectsspectral shapemeson-exchange currents0103 physical sciencesweak interactionsMatrix elementAtomic physicsAnomaly (physics)ydinfysiikka010306 general physicslcsh:Physicsdescription
The effects of the enhancement of the axial-charge matrix element γ5 were studied in medium heavy and heavy nuclei for first-forbidden J+↔J− decay transitions using the nuclear shell model. Noticeable dependence on the enhancement ϵMEC of the axial-charge matrix element, as well as on the value of the axial-vector coupling constant gA was found in the spectral shapes of $^{93}$Y, $^{95}$Sr, and $^{97}$Y. The importance of the spectrum of $^{138}$Cs in the determination of gA is discussed. Half-life analyses in the A≈95 and A≈135 regions were done, and consistent results gA≈0.90, 0.75, and 0.65, corresponding to the three enhancement scenarios ϵMEC=1.4, 1.7, and 2.0, were obtained. Connection to the reactor-antineutrino anomaly is pointed out.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-06-01 | Physics Letters B |