The quark-lepton unification : LHC data and neutrino masses

Abhijit Samanta

Published 2011-12-06, updated 2013-11-14Version 4

The recent discovery of nonzero $\theta_{13}$ (equal to Cabbibo angle $\theta_C$ up to a factor of $\sqrt{2}$), the masses of supersymmetric particles $\gapp$ TeV from LHC data, and the sum of three active neutrino masses $\sum_i m_{\nu_i}\lapp 1$ eV from the study of large scale structure of the universe motivate to study whether quark and lepton mixing have the same origin at the grand unification scale. We find that both results from neutrino experiments and LHC are complementary in quark-lepton unified model. A new constraint on SUSY parameters appears from electroweak symmetry breaking with a new correlation between the lower bounds on sparticle masses and the upper bound on $\sum_i m_{\nu_i}$. In addition, we find that only $\mu>0$ (which is favored by $(g-2)$ of muon) is allowed and $m_{\tilde q, \tilde \l} \gapp$ TeV if $\sum_i m_{\nu_i} \lapp 1$ eV. On the other hand, a small change in lower limit on $\theta_{13}$ from zero leads to a large increase in lower limits on sparticles masses ($\gapp 2$ TeV), which are also the bounds if recently discovered boson at LHC with mass around 125 GeV is the Higgs boson.