PT Journal
AU Helo, JC
   Hirsch, M
   Ota, T
TI Long-range contributions to double beta decay revisited
SO Journal of High Energy Physics
JI J. High Energy Phys.
PY 2016
BP 006
EP 32pp
VL 06
IS 6
DI 10.1007/JHEP06(2016)006
LA English
DE Beyond Standard Model; Neutrino Physics
AB We discuss the systematic decomposition of all dimension-7 (d = 7) lepton number violating operators. These d = 7 operators produce momentum enhanced contributions to the long-range part of the 0 nu beta beta decay amplitude and thus are severely constrained by existing half-live limits. In our list of possible models one can find contributions to the long-range amplitude discussed previously in the literature, such as the left-right symmetric model or scalar leptoquarks, as well as some new models not considered before. The d = 7 operators generate Majorana neutrino mass terms either at tree-level, 1-loop or 2-loop level. We systematically compare constraints derived from the mass mechanism to those derived from the long-range 0 nu beta beta decay amplitude and classify our list of models accordingly. We also study one particular example decomposition, which produces neutrino masses at 2-loop level, can fit oscillation data and yields a large contribution to the long-range 0 nu beta beta decay amplitude, in some detail.
ER