We study the possibility to test the type I seesaw mechanism for neutrino masses at the CERN Large Hadron Collider. The inclusion of three generations of right-handed neutrinos ($N_i$) provides an attractive option of gauging the $B-L$ accidental symmetry in the standard model (as well as an extended symmetry $X=Y-5(B-L)/4$). The production mechanisms for the right-handed neutrinos through the $Z^{\prime }$ gauge boson in the $U(1{)}_{B-L}$ and $U(1{)}_X$ extensions of the standard model are studied. We discuss the flavor combinations of the charged leptons from the decays of $N_i$ in the $\Delta L=2$ channels. We find that the clean channels with dilepton plus jets and possible secondary vertices of the $N$ decay could provide conclusive signals at the LHC in connection with the hierarchical pattern of the light neutrino masses and mixing properties within the type I seesaw mechanism.

• Received 1 August 2009

DOI:https://doi.org/10.1103/PhysRevD.80.073015