Probing new physics in the neutrinoless double beta decay using electron angular correlation
Year: 2007
Type: article
Abstract: The angular correlation of the electrons emitted in the neutrinoless double beta decay ($0\ensuremath{\nu}2\ensuremath{\beta}$) is presented using a general Lorentz invariant effective Lagrangian for the leptonic and hadronic charged weak currents. We show that the coefficient $K$ in the angular correlation $d\ensuremath{\Gamma}/d\mathrm{cos}\ensuremath{\theta}\ensuremath{\propto}(1\ensuremath{-}K\mathrm{cos}\ensuremath{\theta})$ is essentially independent of the nuclear matrix element models and present its numerical values for the five nuclei of interest ($^{76}\mathrm{Ge}$, $^{82}\mathrm{Se}$, $^{100}\mathrm{Mo}$, $^{130}\mathrm{Te}$, and $^{136}\mathrm{Xe}$), assuming that the $0\ensuremath{\nu}2\ensuremath{\beta}$ decays in these nuclei are induced solely by a light Majorana neutrino, ${\ensuremath{\nu}}_{M}$. This coefficient varies between $K=0.81$ (for the $^{76}\mathrm{Ge}$ nucleus) and $K=0.88$ (for the $^{82}\mathrm{Se}$ and $^{100}\mathrm{Mo}$ nuclei), calculated taking into account the effects from the nucleon recoil, the $S$ and $P$ waves for the outgoing electrons and the electron mass. Deviation of $K$ from its values derived here would indicate the presence of new physics (NP) in addition to a light Majorana neutrino, and we work out the angular coefficients in several ${\ensuremath{\nu}}_{M}+\mathrm{NP}$ scenarios for the $^{76}\mathrm{Ge}$ nucleus. As an illustration of the correlations among the $0\ensuremath{\nu}2\ensuremath{\beta}$ observables (half-life ${T}_{1/2}$, the coefficient $K$, and the effective Majorana neutrino mass $|⟨m⟩|$) and the parameters of the underlying NP model, we analyze the left-right symmetric models, taking into account current phenomenological bounds on the right-handed ${W}_{R}$-boson mass and the left-right mixing parameter $\ensuremath{\zeta}$.
Authors: A. Ali, A. V. Borisov, D. V. Zhuridov
Language: English
Topic: Neutrino Physics Research
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2144077066