New Physics Models Facing Lepton Flavor Violating Higgs Decays at the Percent Level

Abstract

We speculate about the possible interpretations of the recently observed excess in the $h\to \tau \mu$ decay. We derive a robust lower bound on the Higgs boson coupling strength to a tau and a muon, even in presence of the most general new physics affecting other Higgs properties. Then we reevaluate complementary indirect constraints coming from low energy observables as well as from theoretical considerations. In particular, the tentative signal should lead to $\tau \to \mu \gamma$ at rates which could be observed at Belle II. In turn we show that, barring fine-tuned cancellations, the effect can only be accommodated within models with an extended scalar sector. These general conclusions are demonstrated using a number of explicit new physics models. Finally we show how, given the $h\to \tau \mu$ signal, the current and future searches for $\mu \to e\gamma$ and $\mu \to e$ nuclear conversions unambiguously constrain the allowed rates for $h\to \tau e$.

34 pages, 9 figures, expanded Section V.D with the fine-tuning solution; conclusions unchanged

References in corpus (7)

• 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 $L_{\mu }-L_{\tau }$
• Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes
• Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs
• Higgs $\to \mu \tau$ in Abelian and Non-Abelian Flavor Symmetry Models
• Lepton-Flavored Scalar Dark Matter with Minimal Flavor Violation

Cited by in corpus (68)

• Physics of leptoquarks in precision experiments and at particle colliders
• One Leptoquark to Rule Them All: A Minimal Explanation for $R_{D^{(\ast )}}$, $R_K$ and $(g-2{)}_{\mu }$
• From the trees to the forest: a review of radiative neutrino mass models
• A perturbed lepton-specific two-Higgs-doublet model facing experimental hints for physics beyond the Standard Model
• Towards a unified explanation of $R_{D^{(\ast )}}$, $R_K$ and $(g-2{)}_{\mu }$ anomalies in a left-right model with leptoquarks
• Lepton flavor (universality) violation in rare kaon decays
• A $L_{\mu }-L_{\tau }$ theory of Higgs flavor violation and $(g-2{)}_{\mu }$
• Accidental matter at the LHC
• Correlating $h\to {\mu }^{+}{\mu }^{-}$ to the Anomalous Magnetic Moment of the Muon via Leptoquarks
• Full parameter scan of the Zee model: exploring Higgs lepton flavor violation
• Uncovering Mass Generation Through Higgs Flavor Violation
• LHC constraints and prospects for $S_1$ scalar leptoquark explaining the $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ anomaly
• Scalar Leptoquarks in Leptonic Processes
• Higgs Physics: It ain't over till it's over
• $\tau$- and $\mu$-physics in a general two Higgs doublet model with $\mu -\tau$ flavor violation
• Two Higgs doublets to explain the excesses $pp\to \gamma \gamma (750\mathrm{GeV})$ and $h\to {\tau }^{\pm }{\mu }^{\mp }$
• Analysis of the $h,H,A\to \tau \mu$ decays induced from SUSY loops within the Mass Insertion Approximation
• Leptoquark explanation of $h\to \mu \tau$ and muon $(g-2)$
• Leptoquark induced rare decay amplitudes $h\to {\tau }^{\mp }{\mu }^{\pm }$ and $\tau \to \mu \gamma$
• Higgs lepton flavour violation: UV completions and connection to neutrino masses
• Large $h\to bs$ in generic two-Higgs-doublet models
• Naturally Large Radiative Lepton Flavor Violating Higgs Decay Mediated by Lepton-flavored Dark Matter
• The Lepton Flavour Violating Higgs Decays at the HL-LHC and the ILC
• Higgs Decay $h\to \mu \tau$ with Minimal Flavor Violation
• Decay of standard model-like Higgs boson $h\to \mu \tau$ in a 3-3-1 model with inverse seesaw neutrino masses
• $h,Z\to {\ell }_i{\bar{\ell }}_j$, $\Delta a_{\mu }$, $\tau \to (3\mu ,\mu \gamma )$ in generic two-Higgs-doublet models
• Rare semileptonic $B\to K(\pi )l_i^{-}{l}_j^{+}$ decay in vector leptoquark model
• Flavor Changing Leptonic Decays of Heavy Higgs Bosons
• Lepton flavor violating Higgs decay $h\to \mu \tau$ in the littlest Higgs Model with T-parity
• New Signatures of Flavor Violating Higgs Couplings
• Lepton Flavor Violation in the singlet-triplet scotogenic model
• Flavor violating signatures of lighter and heavier Higgs bosons within the Two Higgs Doublet Model Type-III at the LHeC
• Lepton flavor violating Higgs boson decays in seesaw models: new discussions
• $H\to \ell {\ell }^{\prime }$ in the Simplest Little Higgs Model
• Higgs lepton flavor violating decays in Two Higgs Doublet Models
• Bounds on LFV Higgs decays in a vector-like lepton model and searching for doubly charged leptons at the LHC
• Large BR(h->tau mu) in the MSSM?
• Collider Constraints on Lepton Flavor Violation in the 2HDM
• Flavor techniques for LFV processes: Higgs decays in a general seesaw model
• 125 GeV Higgs decay with lepton flavor violation in the $\mu \nu$SSM
• Lepton flavor violating decay of SM-like Higgs in a radiative neutrino mass model
• Flavor anomalies at the LHC and the R-parity violating supersymmetric model extended with vectorlike particles
• Minimal Models of Loop-Induced Higgs Lepton Flavor Violation
• The ATLAS Diboson Resonance in Non-Supersymmetric SO(10)
• Unified resolution of the $R(D)$ and $R(D^{\ast })$ anomalies and the lepton flavor violating decay $h\to \mu \tau$
• Lepton flavor violating Higgs boson decay $h\to \mu \tau$ at the ILC
• On the amplitudes for the CP-conserving $K^{\pm }(K_S)\to {\pi }^{\pm }({\pi }^0){\ell }^{+}{\ell }^{-}$ rare decay modes
• Lepton-flavour-violating gluonic operators: constraints from the LHC and low energy experiments
• CP violation in $h\to \tau \tau$ and LFV $h\to \mu \tau$
• Higgs-$\mu$-$\tau$ Coupling at High and Low Energy Colliders
• Constraining Lepton Flavor Violating Higgs Couplings at the HL-LHC in the Vector Boson Fusion Channel
• Higgs boson decays with lepton flavor violation in the $B-L$ symmetric SSM
• One loop contributions to neutral Higgs decay h-->mu tau
• Yukawa sector for LFV in $h\to \mu \tau$ and CP violation in $h\to \tau \tau$
• Phenomenology of SU(5) low-energy realizations: the diphoton excess and Higgs flavor violation
• On the exotic Higgs decays in effective field theory
• Lepton-flavour violating decays in theories with dimension 6 operators
• $K\to \pi {\ell }^{+}{\ell }^{-}$ form factor in the Large-N${}_c$ and cut-off regularization method
• Flavor-Changing Higgs Decays in Grand Unification with Minimal Flavor Violation
• Lepton flavor violating decays of the SM-like Higgs boson $h\to e_i{e}_j$, and $e_i\to e_j\gamma$ in a flipped 3-3-1 model
• Lepton flavor violating Higgs decay at $e^{+}{e}^{-}$ colliders
• Michel parameters for $\tau$ decays $\tau \to l\nu \bar{\nu }(l=e,\mu )$ in a general two Higgs doublet model with $\mu -\tau$ flavor violation
• Lepton flavor-violating decays of the Higgs boson from sgoldstino mixing
• Neutrino phenomenology and keV dark matter in 2HDM with $A_4$ symmetry
• Electric dipole moment of the neutron in Two Higgs Doublet Models with flavor changing
• $\mathbf{B}-\mathbf{L}$ model with ${\mathbf{D}}_4\times {\mathbf{Z}}_4\times {\mathbf{Z}}_2$ symmetry for fermion mass hierarchies and mixings
• New Physics in $B$ decays
• Vacuum stability in an extended standard model with a leptoquark