Abstract
A search for physics beyond the standard model in the final state with two same-flavour leptons (electrons or muons) and two quarks produced in proton–proton collisions at $\sqrt{s}$ = 13TeV is presented. The data were recorded by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 2.3 $fb^{−1}$. The observed data are in good agreement with the standard model background prediction. The results of the measurement are interpreted in the framework of a recently proposed model in which a heavy Majorana neutrino, $N_\ell$, stems from a composite-fermion scenario. Exclusion limits are set for the first time on the mass of the heavy composite Majorana neutrino, $m_{N_\ell}$, and the compositeness scale $\Lambda$. For the case $m_{N_\ell} = \Lambda$, the existence of $N_e (N_\mu)$ is excluded for masses up to 4.60 (4.70) TeV at 95% confidence level.
CMS Collaboration