Probing Majorana neutrinos and the Weinberg operator in the same-charge dimuon channel through vector boson fusion processes in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$

A first search probing Majorana neutrinos and the Weinberg operator in vector boson fusion processes at the LHC is presented. The search is performed in the same-charge dimuon final state using a proton-proton collision data set, recorded by the CMS detector, at a center-of-mass energy of $13~\mathrm{TeV}$ and corresponding to a total integrated luminosity of $138~\mathrm{fb}^{-1}$. The final state consists of two well-identified isolated muons with the same charge, and two jets with a large rapidity separation as well as a large dijet mass. The results are found to agree with the predictions of the standard model. Constraints are derived on model parameters accordingly. These limits significantly extend the mass range probed for heavy Majorana neutrinos compared with previous searches at the LHC. They also serve as a first test of the Weinberg operator at colliders.