Lepton Flavor Violating $h\to\tau\mu$ decay induced by leptoquarks

Abstract

The flavor changing neutral current decay $h\to\tau\mu$ is studied in a renormalizable scalar leptoquark model with no proton decay. Analytical expressions for the one-loop level contributions of a scalar leptoquark to the decay width of the process $h\to\tau\mu$ are presented. We find a viable model parameter space via the current constraints on the muon ($g-2$), the decay $\tau\to\mu\gamma$, the LHC Higgs boson data and the direct leptoquark searches at the LHC. Then, we evaluate branching ratio of the decay $h\to\tau\mu$induced by leptoquarks; we find that it is of the order of $10^{-8}-10^{-7}$ ($10^{-8}$; $10^{-9}-10^{-8}$)for a scalar leptoquark mass equal to $m_{\Omega_{5/3}}=1$ TeV ($m_{\Omega_{5/3}}=2$; $m_{\Omega_{5/3}}=10$ TeV). Finally, we evaluate the number of events produced at future hadron colliders from both the $h\to\tau\mu$ decay and the potential Standard Model background finding a potentialevidence for the $h\to\tau\mu$ decay.

Flavor changing flavon decay ɸ→tc (ɸ = HF, AF ) at the high luminosity large hadron collider

“…In the framework of the SM there are no tree-level flavor changing neutral currents (FCNC), which are, however, predicted by several SM extensions, being mediated by the Higgs boson or other new scalar or vector boson particles. In the context of these models, it is worth studying any signal that could give clues for new physics (NP), such as the widely studied process φ → τ µ, with φ a CP -even or CP -odd scalar boson [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. FCNC signals can also arise from the top quark decays t → cX (X = φ, γ, g, Z, H) [18][19][20][21][22][23][24][25][26], and from the less studied decay of a new heavy scalar boson into a top-charm quark pair [27], which could be searched at the LHC and the future high luminosity LHC (HL-LHC).…”