PT Journal
AU Cepedello, R
   Deppisch, FF
   Gonzalez, L
   Hati, C
   Hirsch, M
TI Neutrinoless Double-Beta Decay with Nonstandard Majoron Emission
SO Physical Review Letters
JI Phys. Rev. Lett.
PY 2019
BP 181801
EP 6pp
VL 122
IS 18
DI 10.1103/PhysRevLett.122.181801
LA English
AB We present a novel mode of neutrinoless double-beta decay with emission of a light Majoron-like scalar particle phi. We assume it couples via an effective seven-dimensional operator with a (V + A) lepton current and (V +/- A) quark currents leading to a long-range contribution that is unsuppressed by the light neutrino mass. We calculate the total double-beta decay rate and determine the fully differential shape for this mode. We find that future double-beta decay searches are sensitive to scales of the order Lambda(NP) approximate to 1 TeV for the effective operator and a light scalar m(phi) < 0.2 MeV, based on ordinary double-beta decay Majoron searches. The angular and energy distributions can deviate considerably from that of two-neutrino double-beta decay, which is the main background. We point out possible ultraviolet completions where such an effective operator can emerge.
ER