Search for right-handed Majorana neutrinos at LHC in the ATLAS detector

In this paper, we briefly recall the main characteristics of the minimal Left-Right Symmetric Model, a gauge theory which suggests that parity gets restored at high energy and which may also allow neutrinos to be massive. If neutrinos turn out to be Majorana particles, the See-Saw mechanism implies that the light left-handed neutrinos should have heavy right-handed partners. In this theoret ical framework, one may expect the discovery of three new gauge bosons ($W_{R}^{+}$, $W_{R}^{-}$ and $Z'$) as well as heavy right-handed Majorana neutrinos ($N_{l}$) at the future LHC. Two possibl e signals have been simulated in the ATLAS detector~: $pp \rightarrow W_{R} \rightarrow eN_{e} \rightarrow eejj$ and $pp \rightarrow Z' \rightarrow N_{e}N_{e} \rightarrow eejjjj$. After three ye ars of data-taking at nominal luminosity and an appropriate reduction of the background, the first channel may allow us to discover $W_{R}$ and $N_{e}$ up to masses of 6.4 and 3.3 TeV respective ly, while the second process may lead to the observation of the $Z'$ boson up to a mass of 4.5 TeV, provided that $m_{N_{e}}$ is smaller than 1.7 TeV.