Higgs-$\mu$-$\tau$ Coupling at High and Low Energy Colliders

Abstract

There is no tree-level flavor changing neutral current (FCNC) in the standard model (SM) which contains only one Higgs doublet. If more Higgs doublets are introduced for various reasons, the tree level FCNC would be inevitable except extra symmetry was imposed. Therefore FCNC processes are the excellent probes for the physics beyond the SM (BSM). In this paper, we studied the lepton flavor violated (LFV) decay processes $h\to \mu \tau$ and $\tau \to \mu \gamma$ induced by Higgs-$\mu$-$\tau$ vertex. For $\tau \to \mu \gamma$, its branching ratio is also related to the $ht\bar{t}$, $h{\tau }^{+}{\tau }^{-}$ and $h{W}^{+}{W}^{-}$ vertices. We categorized the BSM into two scenarios for the Higgs coupling strengths near or away from SM. For the latter scenario, we took the spontaneously broken two Higgs doublet model (Lee model) as an example. We considered the constraints by recent data from LHC and B factories, and found that the measurements gave weak constraints. At LHC Run II, $h\to \mu \tau$ will be confirmed or set stricter limit on its branching ratio. Accordingly, $\text{Br}(\tau \to \mu \gamma )\lesssim \mathcal{O}(10^{-10}-10^{-8})$ for general chosen parameters. For the positive case, $\tau \to \mu \gamma$ can be discovered with $\mathcal{O}(10^{10})$ $\tau$ pair samples at SuperB factory, Super $\tau$-charm factory and new Z-factory. The future measurements for $\text{Br}(h\to \mu \tau )$ and $\text{Br}(\tau \to \mu \gamma )$ will be used to distinguish these two scenarios or set strict constraints on the correlations among different Higgs couplings, please see Table II in the text for details.

18 pages, 10 figures, 2 table; more references added; more discussions about cancellation in the amplitude added accoeding to the referee's suggestions

References in corpus (15)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Explaining $h\to {\mu }^{\pm }{\tau }^{\mp }$, $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B\to K{\mu }^{+}{\mu }^{-}/B\to K{e}^{+}{e}^{-}$ in a two-Higgs-doublet model with gauged $L_{\mu }-L_{\tau }$
• Addressing the LHC flavour anomalies with horizontal gauge symmetries
• Search for lepton-flavour-violating decays of the Higgs boson
• Higgs $\to \mu \tau$ in Abelian and Non-Abelian Flavor Symmetry Models
• Explaining the CMS Higgs flavor violating decay excess
• Lepton-flavor-violating Higgs decay $h\to \mu \tau$ and muon anomalous magnetic moment in a general two Higgs doublet model
• New Physics Models Facing Lepton Flavor Violating Higgs Decays at the Percent Level
• Search for lepton-flavour-violating $H\to \mu \tau$ decays of the Higgs boson with the ATLAS detector
• Higgs Flavor Violation as a Signal to Discriminate Models
• Leptoquark induced rare decay amplitudes $h\to {\tau }^{\mp }{\mu }^{\pm }$ and $\tau \to \mu \gamma$
• Lepton-Flavored Scalar Dark Matter with Minimal Flavor Violation
• Flavor and CP violation in Higgs decays
• Higgs physics: Review of recent results and prospects from ATLAS and CMS

Cited by in corpus (13)

• Flavour Changing Higgs Couplings in a Class of Two Higgs Doublet Models
• $\tau$- and $\mu$-physics in a general two Higgs doublet model with $\mu -\tau$ flavor violation
• The Lepton Flavour Violating Higgs Decays at the HL-LHC and the ILC
• Higgs lepton flavor violating decays in Two Higgs Doublet Models
• Collider Constraints on Lepton Flavor Violation in the 2HDM
• Lepton Flavor Violating Decays of Neutral Higgses in Extended Mirror Fermion Model
• 125 GeV Higgs decay with lepton flavor violation in the $\mu \nu$SSM
• Invisible Higgs Decay at the LHeC
• Minimal Models of Loop-Induced Higgs Lepton Flavor Violation
• The ATLAS Diboson Resonance in Non-Supersymmetric SO(10)
• Higgs boson decays with lepton flavor violation in the $B-L$ symmetric SSM
• One loop contributions to neutral Higgs decay h-->mu tau
• Lightness of a Higgs Boson and Spontaneous CP-violation in the Lee Model: An Alternative Scenario