Same-Sign Dilepton Production via Heavy Majorana Neutrinos in Proton-Proton Collisions

Abstract

We discuss same-sign dilepton production mediated by Majorana neutrinos in high-energy proton-proton collisions $pp\text{ra}{\ell }^{+}{\ell }^{\prime +}X$ for $\ell ,{\ell }^{\prime }=e,\mu ,\tau$ at the LHC energy $\sqrt{s}=14$ TeV. Assuming one heavy Majorana neutrino of mass $m_N$, we present discovery limits in the $(m_N,|U_{\ell N}{U}_{{\ell }^{\prime }N}|)$ plane where $U_{\ell N}$ are the mixing parameters. Taking into account the present limits from low energy experiments, we show that at LHC one has sensitivity to heavy Majorana neutrinos up to a mass $m_N\le 2$ -- 5 TeV in the dilepton channels $\mu \mu ,\tau \tau$, and $\mu \tau$, but the dilepton states $e\ell$ will not be detectable due to the already existing constraints from neutrinoless double beta decay.

Comments: 7 pages, 2 figures (requires 10lomcon.sty, cite.sty); added two references; to be published in the Proceedings of the 10th Lomonosow Conference on Elementary Particle Physics (Moscow State University, Moscow, 23 - 28 August 2001)