Neutrino masses, dominant neutrinoless double beta decay, and observable lepton flavor violation in left-right models and SO(10) grand unification with low mass WR, ZR bosons

While the detection of W-R-boson at the Large Hadron Collider is likely to resolve the mystery of parity violation in weak interaction, observation of neutrinoless double beta decay (0 nu beta beta) is expected to determine whether neutrinos are Majorana fermions. In this work we consider a class of LR models with TeV scale W-R, Z(R), bosons but having parity restoration at high scales where they originate from well known Pati-Salam symmetry or SO(10) grand unified theory minimally extended to accommodate inverse seesaw frame work for neutrino masses. Most dominant new contribution to neutrinoless double beta decay is noted to occur via WL-WL- mediation involving lighter sterile neutrino exchanges. The next dominant contribution is found to be through WL-WR- mediation involving both light and heavy right-handed neutrino or sterile neutrino exchanges. The quark-lepton symmetric origin of the computed value of the Dirac neutrino mass matrix is also found to play a crucial role in determining these and other results on lepton flavor violating branching ratios for tau -> e + gamma, tau -> mu + gamma, and mu -> e + gamma accessible to ongoing search experiments. The underlying non-unitarity matrix is found to manifest in substantial CP-violating effects even when the leptonic Dirac phase delta(CP) similar or equal to 0, pi, 2 pi. Finally we explore a possible origin of the model in non-supersymmetric SO(10) grand unified theory where, in addition to low mass W-R(+/-) and Z(R) bosons accessible to Large Hadron Collider, the model is found to predict observable neutron-antineutron oscillation and lepto-quark gauge boson mediated rare kaon decay with Br (K-L -> mu(e) over bar) approximate to (10(-9) - 10(-11)).