Neutrinolessββdecays to excited0+states and the Majorana-neutrino mass

2016

Nuclear matrix elements for0νββdecays with light or heavy Majorana-neutrino exchange

2015

We compute the nuclear matrix elements (NMEs) corresponding to the neutrinoless double beta ($0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$) decays of nuclei which attract current experimental interest. We concentrate on ground-state-to-ground-state decay transitions mediated by light (l-NMEs) or heavy (h-NMEs) Majorana neutrinos. The computations are done in realistic single-particle model spaces using the proton-neutron quasiparticle random-phase approximation (pnQRPA) with two-nucleon interactions based on the Bonn one-boson-exchange $G$ matrix. Both the l-NMEs and the h-NMEs include the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak …

Analysis of the Intermediate-State Contributions to Neutrinoless Double β− Decays

2016

A comprehensive analysis of the structure of the nuclear matrix elements (NMEs) of neutrinoless double beta-minus (0νβ-β-) decays to the0+ground and first excited states is performed in terms of the contributing multipole states in the intermediate nuclei of0νβ-β-transitions. We concentrate on the transitions mediated by the light (l-NMEs) Majorana neutrinos. As nuclear model we use the proton-neutron quasiparticle random-phase approximation (pnQRPA) with a realistic two-nucleon interaction based on the Bonn one-boson-exchangeGmatrix. In the computations we include the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak currents and restore the isospi…

Recursive method for computing matrix elements for two-body interactions

2015

A recursive method for the efficient computation of two-body matrix elements is presented. The method consists of a set of recursion relations for the computationally demanding radial integral and adds one more tool to the set of computational methods introduced by Horie and Sasaki [H. Horie and K. Sasaki, Prog. Theor. Phys. 25, 475 (1961)]. The neutrinoless double-$\ensuremath{\beta}$ decay will serve as the primary application and example, but the method is general and can be applied equally well to other kinds of nuclear structure calculations involving matrix elements of two-body interactions.

Neutrinoless ββ decays to excited 0+ states and the Majorana-neutrino mass

2016

The nuclear matrix elements (NMEs) corresponding to the neutrinoless double-β (0νββ) decays to excited 0+ states of major experimental interest are calculated. All these decay transitions are electron emitting (0νβ−β− decays) and take place in the mass A = 76,82,96,100,110,116,124,130,136 nuclei. This work is an extension of our previous work [Phys. Rev. C 91, 024613 (2015)], where 0νββ decays to the ground states of the same nuclei were treated. We calculate the NMEs for transitions mediated by both the light (l-NMEs) and the heavy (h-NMEs) Majorana neutrinos. A higher-QRPA (quasiparticle random-phase approximation) framework, the multiple-commutator model, is adopted for the calculations,…

Nuclear matrix elements for 0νββ decays with light or heavy Majorana-neutrino exchange

2015

We compute the nuclear matrix elements (NMEs) corresponding to the neutrinoless double beta (0νββ) decays of nuclei which attract current experimental interest. We concentrate on ground-state-to-ground-state decay transitions mediated by light (l-NMEs) or heavy (h-NMEs) Majorana neutrinos. The computations are done in realistic single-particle model spaces using the proton-neutron quasiparticle random-phase approximation (pnQRPA) with two-nucleon interactions based on the Bonn one-boson-exchange G matrix. Both the l-NMEs and the h-NMEs include the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak currents. In addition, both types of NMEs are correct…