Dilepton bounds on left-right symmetry at the LHC run II and neutrinoless double beta decay

Abstract

In the light of the new 13 TeV dilepton data set with $3.2\mathrm{f}{\mathrm{b}}^{-1}$ integrated luminosity from the ATLAS collaboration, we derive limits on the $Z^{\prime }$ mass in the context of left-right symmetric models and exploit the complementarity with dijet and $lljj$ data, as well as neutrinoless double beta decay. We keep the ratio of the left- and right-handed gauge coupling free in order to take into account different patterns of left-right symmetry breaking. By combining the dielectron and dimuon data we can exclude $Z^{\prime }$ masses below $3$ TeV for $g_R=g_L$, and for $g_R\sim 1$ we rule out masses up to $\sim 4$ TeV. Those comprise the strongest direct bounds on the $Z^{\prime }$ mass from left-right models up to date. We show that in the usual plane of right-handed neutrino and charged gauge boson mass, dilepton data can probe a region of parameter space inaccessible to neutrinoless double beta decay and $lljj$ studies. Lastly, through the mass relation between $W_R$ and $Z^{\prime }$ we present an indirect bound on the lifetime of neutrinoless double beta decay using dilepton data. Our results prove that the often ignored dilepton data in the context of left-right models actually provide important complementary limits.

Comments: 7 pages, 6 figures. Matches version published in Phys. Lett. B