TY  - JOUR
AU  - Abada, A.
AU  - De Romeri, V.
AU  - Lucente, M.
AU  - Teixeira, A. M.
AU  - Toma, T.
PY  - 2018
DA  - 2018//
TI  - Effective Majorana mass matrix from tau and pseudoscalar meson lepton number violating decays
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 169
EP  - 57pp
VL  - 02
IS  - 2
PB  - Springer
KW  - Beyond Standard Model
KW  - Neutrino Physics
AB  - An observation of any lepton number violating process will undoubtedly point towards the existence of new physics and indirectly to the clear Majorana nature of the exchanged fermion. In this work, we explore the potential of a minimal extension of the Standard Model via heavy sterile fermions with masses in the [0.1-10] GeV range concerning an extensive array of "neutrinoless" meson and tau decay processes. We assume that the Majorana neutrinos are produced on-shell, and focus on three-body decays. We conduct an update on the bounds on the active-sterile mixing elements, vertical bar U-l alpha 4,U-l beta 4 vertical bar, taking into account the most recent experimental bounds (and constraints) and new theoretical inputs, as well as the effects of a finite detector, imposing that the heavy neutrino decay within the detector. This allows to establish up-to-date comprehensive constraints on the sterile fermion parameter space. Our results suggest that the branching fractions of several decays are close to current sensitivities (likely within reach of future facilities), some being already in conflict with current data (as is the case of K-broken vertical bar -> l(alpha)(broken vertical bar)+l(beta)(+)pi(-), and tau(-)->mu(broken vertical bar)pi(-)pi(-)). We use these processes to extract constraints on all entries of an enlarged definition of a 3 x 3 "effective" Majorana neutrino mass matrix m(v)(alpha beta).
SN  - 1029-8479
UR  - http://arxiv.org/abs/1712.03984
UR  - https://doi.org/10.1007/JHEP02(2018)169
DO  - 10.1007/JHEP02(2018)169
LA  - English
N1  - WOS:000426478100001
ID  - Abada_etal2018
ER  -