TY  - JOUR
AU  - Bonnet, F.
AU  - Hirsch, M.
AU  - Ota, T.
AU  - Winter, W.
PY  - 2012
DA  - 2012//
TI  - Systematic study of the d=5 Weinberg operator at one-loop order
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 153
EP  - 23pp
VL  - 07
IS  - 7
PB  - Springer
KW  - Beyond Standard Model
KW  - Neutrino Physics
AB  - We perform a systematic study of the d = 5 Weinberg operator at the one-loop level. We identify three different categories of neutrino mass generation: (1) finite irreducible diagrams; (2) finite extensions of the usual seesaw mechanisms at one-loop and (3) divergent loop realizations of the seesaws. All radiative one-loop neutrino mass models must fall in to one of these classes. Case (1) gives the leading contribution to neutrino mass naturally and a classic example of this class is the Zee model. We demonstrate that in order to prevent that a tree level contribution dominates in case (2), Majorana fermions running in the loop and an additional Z(2) symmetry are needed for a genuinely leading one-loop contribution. In the type-II loop extensions, the Yukawa coupling will be generated at one loop, whereas the type-I/III extensions can be interpreted as loop-induced inverse or linear seesaw mechanisms. For the divergent diagrams in category (3), the tree level contribution cannot be avoided and is in fact needed as counter term to absorb the divergence.
SN  - 1126-6708
UR  - http://arxiv.org/abs/1204.5862
UR  - https://doi.org/10.1007/JHEP07(2012)153
DO  - 10.1007/JHEP07(2012)153
LA  - English
N1  - WOS:000307299800031
ID  - Bonnet_etal2012
ER  -