To explain the small neutrino masses, heavy Majorana neutrinos are introduced in the left-right twin Higgs model. The heavy neutrinos—together with the charged scalars and the heavy gauge bosons—may contribute large mixings between the neutrinos and the charged leptons, which may induce some distinct lepton-flavor-violating processes. We check ${\overline{\ell }}_i{\ell }_j$ ($i,j=e,\mu ,\tau ,i\ne j$) production in $\gamma \gamma$ collisions in the left-right twin Higgs model, and find that the production rates may be large in some specific parameter space. In optimal cases, it is even possible to detect them with reasonable kinematical cuts. We also show that these collisions can effectively constrain the model parameters—such as the Higgs vacuum expectation value, the right-handed neutrino mass, etc.—and may serve as a sensitive probe of this new physics model.

• Received 4 January 2017

DOI:https://doi.org/10.1103/PhysRevD.96.035005