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Register a new userDuality in Left-Right Symmetric Seesaw Mechanism
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E. Kh. Akhmedov
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We consider type I+II seesaw mechanism, where the exchanges of both right-handed neutrinos and isotriplet Higgs bosons contribute to the neutrino mass. Working in the left-right symmetric framework and assuming the mass matrix of light neutrinos $m_ u$ and the Dirac-type Yukawa couplings to be known, we find the triplet Yukawa coupling matrix $f$, which carries the information about the masses and mixing of the right-handed neutrinos. We show that in this case there exists a duality: for any solution $f$, there is a dual solution $hat{f}=m_ u/v_L-f$, where $v_L$ is the VEV of the triplet Higgs. Thus, unlike in pure type I (II) seesaw, there is no unique allowed structure for the matrix $f$. For $n$ lepton generations the number of solutions is $2^n$. We develop an exact analytic method of solving the seesaw non-linear matrix equation for $f$.
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We propose a low scale renormalizable left-right symmetric theory that successfully explains the observed SM fermion mass hierarchy, the tiny values for the light active neutrino masses, the lepton and baryon asymmetries of the Universe, as well as the muon and electron anomalous magnetic moments. In the proposed model the top and exotic quarks obtain masses at tree level, whereas the masses of the bottom, charm and strange quarks, tau and muon leptons are generated from a tree level Universal Seesaw mechanism, thanks to their mixings with the charged exotic vector like fermions. The masses for the first generation SM charged fermions arise from a radiative seesaw mechanism at one loop level, mediated by charged vector like fermions and electrically neutral scalars. The light active neutrino masses are produced from a one-loop level inverse seesaw mechanism. Our model is also consistent with the experimental constraints arising from the Higgs diphoton decay rate. We also discuss the $Z^prime$ and heavy scalar production at a proton-proton collider.
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