Implications of a purely right-handed b-decay coupling

Abstract

We examine the implications of the hypothesis that the decays of the bottom quark occur via pure right-handed couplings . We show that the existing lower limits on the lifetimes for neutrinoless double beta decay severely restrict the neutrino sector of the model and would be satisfied in a natural manner if there is either an L e − L µ or an L e − L τ symmetry in the model. We then show that the cosmological mass density constraints in combination with SN1987A observations imply lower bounds on the masses of the right-handed neutrinos of about 100 MeV ( about 65 MeV if there are Goldstone bosons coupling to ν R 's) and also imply that the case of L e − L µ symmetry is inconsistent with data unless there are flavor-changing neutral currents involving the right-handed neutrinos.

New fermions and a vectorlike third generation in SU(3)C⊗SU(3)L

“…In such a model the smallness of the b to c coupling is due not to the value of the corresponding mixing angle but to the small value of the right-handed Fermi constant GFR, and the right-handed Wn boson must be light since [45] ___ and T are heavy.…”

“…These ideas were worked out in the context of an SU(2) L ⊗ SU(2) R ⊗ U(1) model. In such a model the smallness of the b to c coupling is due not to the value of the corresponding mixing angle but to the small value of the right-handed Fermi constant G F R , and the right-handed W R boson must be light since [38] L . Hence, as we said before, in our models it would be necessary to make a global analysis involving Z-pole observables, CP violation, semileptonic B decays and other processes in order to fit the several parameters appearing in it.…”