[Submitted on 23 Oct 2015]
Testing the importance of collective correlations in neutrinoless decay
J. Menéndez🇩🇪 · N. Hinohara🇺🇸 · J. Engel🇺🇸 · G. Martínez-Pinedo🇩🇪 · T. R. Rodríguez🇪🇸
We investigate the extent to which theories of collective motion can capture the physics that determines the nuclear matrix elements governing neutrinoless double-beta decay. To that end we calculate the matrix elements for a series of isotopes in the full shell, omitting no spin-orbit partners. With the inclusion of isoscalar pairing, a separable collective Hamiltonian that is derived from the shell model effective interaction reproduces the full shell-model matrix elements with good accuracy. A version of the generator coordinate method that includes the isoscalar pairing amplitude as a coordinate also reproduces the shell model results well, an encouraging result for theories of collective motion, which can include more single-particle orbitals than the shell model. We briefly examine heavier nuclei relevant for experimental double-beta decay searches, in which shell-model calculations with all spin-orbit partners are not feasible; our estimates suggest that isoscalar pairing also plays a significant role in these nuclei, though one we are less able to quantify precisely.
- Comments:
- 9 pages, 7 figures, published version
- Subjects:
- Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
- arXiv:
- 1510.06824 [pdf]