Arbitrary mass Majorana neutrinos in neutrinoless double beta decay

AbstraktAbstract

We revisit the mechanism of neutrinoless double beta (0νββ) decay mediated by the exchange with the heavy Majorana neutrino N of arbitrary mass mN, slightly mixed ~UeN with the electron neutrino νe. By assuming the dominance of this mechanism, we update the well-known 0νββ-decay exclusion plot in the mN−UeN plane taking into account recent progress in the calculation of nuclear matrix elements within quasiparticle random phase approximation and improved experimental bounds on the 0νββ-decay half-life of 76Ge and 136Xe. We also consider the known formula approximating the mN dependence of the 0νββ-decay nuclear matrix element in a simple explicit form. We analyze its accuracy and specify the corresponding parameters, allowing one to easily calculate the 0νββ-decay half-life for arbitrary mN for all the experimentally interesting isotopes without resorting to real nuclear structure calculations.

We revisit the mechanism of neutrinoless double beta (0νββ) decay mediated by the exchange with the heavy Majorana neutrino N of arbitrary mass mN, slightly mixed ~UeN with the electron neutrino νe. By assuming the dominance of this mechanism, we update the well-known 0νββ-decay exclusion plot in the mN−UeN plane taking into account recent progress in the calculation of nuclear matrix elements within quasiparticle random phase approximation and improved experimental bounds on the 0νββ-decay half-life of 76Ge and 136Xe. We also consider the known formula approximating the mN dependence of the 0νββ-decay nuclear matrix element in a simple explicit form. We analyze its accuracy and specify the corresponding parameters, allowing one to easily calculate the 0νββ-decay half-life for arbitrary mN for all the experimentally interesting isotopes without resorting to real nuclear structure calculations.