Probing neutrino Dirac mass in left-right symmetric models at the LHC and next generation colliders
We assess the sensitivity of the LHC, its high energy upgrade, and a prospective 100 TeV hadronic collider to the Dirac Yukawa coupling of the heavy neutrinos in left-right symmetric models (LRSMs). We focus specifically on the trilepton final state in regions of parameter space yielding prompt decays of the right-handed gauge bosons (W_R) and neutrinos (N_R). In the minimal LRSM, the Dirac Yukawa couplings are completely fixed in terms of the mass matrices for the heavy and light neutrinos. In this case, the trilepton signal provides a direct probe of the Dirac mass term for a fixed W_R and N_R mass. We find that while it is possible to discover the W_R at the LHC, probing the Dirac Yukawa couplings will require a 100 TeV pp collider. We also show that the observation of the trilepton signal at the LHC would indicate the presence of a nonminimal LRSM scenario.
Additional Information© 2019 Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3. Received 14 December 2018; published 27 March 2019. J. V. thanks Goran Senjanović for illuminating discussions and useful suggestions during all the stages of this work. J. C. H. thanks Martin Hirsch for useful discussions. J. V., J. C. H. and N. N. are grateful to the UMass Amherst Center for Fundamental Interactions for the hospitality, where they were visitors during the initial stages of this work. J. V. was funded by FONDECYT Grant No. 3170154 and by Conicyt PIA/Basal FB0821. J. C. H. is supported by Chile grants Fondecyt No. 1161463 and Conicyt PIA/ACT 1406. MJRM and H-L.L was supported in part under U.S. Department of Energy Contract No DESC0011095. N. N. was supported by FONDECYT (Chile) Grant No. 3170906. H.-L. L is also supported by the National Science Foundation of China under Grant No. 11875003.
Published - PhysRevD.99.055042.pdf
Submitted - 1812.01630.pdf