Implications of Lorentz violation on Higgs-mediated lepton flavor violation

Abstract

The lepton flavor violating decay of the Higgs boson is studied within two qualitatively different extensions of the Yukawa sector: one renormalizable and the other nonrenormalizable; both incorporating Lorentz violation in a model-independent fashion. These extensions are characterized by Yukawa-like matrices, the former by the constant Lorentz 2-tensor whereas the latter by the constant Lorentz vector It is found that the experimental constraints on the decays severely restrict lepton flavor violating Higgs signals in the renormalizable scenario, as the electromagnetic transitions arise at tree level. In this context, it is found that the branching ratios of the decays and cannot be larger than 10−19 and 10−11, respectively. In the nonrenormalizable scenario, the electromagnetic transitions arise at one-loop level and transitions mediated by the Higgs or the Z gauge boson are induced at tree level, hence we find mild restrictions on lepton flavor violation. Using the experimental limits on the three-body decays to constraint the vector it is found that the branching ratio for the decays is of about 4 × 10−9, more important, a branching ratio of 7 × 10−4 is found for the mode. Accordingly, the decay could be at the reach of future measurements. The lepton flavor violating decays of the Z gauge boson were also studied. In the renormalizable scenario, it was found the undetectable branching ratios and As far as the nonrenormalizable scenario is concerned, it was found that and Although the latter branching ratio is relatively large, it still could not be within the range of future measurements.