A left-right symmetric model with SU(2)-triplet fermions

Abstract

We consider an $SU(3{)}_c\otimes SU(2{)}_L\otimes SU(2{)}_R\otimes U(1{)}_{B-L}$ left-right symmetric model with three Higgs scalars including an $SU(2{)}_L$ doublet, an $SU(2{)}_R$ doublet and an $SU(2{)}_L\otimes SU(2{)}_R$ bidoublet. In addition to usual SU(2)-doublet fermions, our model contains SU(2)-triplet fermions with Majorana masses. The neutral components of the left-handed triplets can contribute a canonical seesaw while the neutral components of the right-handed triplets associated with the right-handed neutrinos can contribute a double/inverse-type seesaw. Our model can be embedded into an SO(10) grand unification theory where the triplets belong to the $45=(1,3,1,0)\oplus (1,1,3,0)\oplus ...$ representations.

Comments: 4 pages. To appear in Phys. Rev. D