Power-aligned 2HDM: a correlative perspective on (g − 2)e,μ

Abstract

With the hypothesis of minimal flavor violation, we find that there exists a power-aligned relation between the Yukawa couplings of the two scalar doublets in the two-Higgs-doublet model with Hermitian Yukawa matrices. Within such a power-aligned framework, it is found that a simultaneous explanation of the anomalies observed in the electron and muon anomalous magnetic moments can be reached with TeV-scale quasi-degenerate Higgs masses, and the resulting parameter space is also phenomenologically safer under the B-physics, Z and τ decay data, as well as the current LHC bounds. Furthermore, the flavor-universal power that enhances the charged-lepton Yukawa couplings prompts an interesting correlation between the two anomalies, which makes the model distinguishable from the (generalized) linearly aligned and the lepton-specific two-Higgs-doublet models that address the same anomalies but in a non-correlative manner, and hence testable by future precise measurements.

Linking the $R_{K^{(\ast)}}$ anomalies to the Hubble tension via a single right-handed neutrino

“…3. This is exactly what we expect, since the effects of the scalars H + , H 0 , A with nearly degenerate masses at the TeV scale induce already suppressed loop corrections to Z → µ + µ − and W → µν decays [50]. From Fig.…”

“…Such a setup is also adopted to allow significant Yukawa contributions while evading the severe constraints from electroweak precision observables, Z-boson and τ -lepton decays (see, e.g., Ref. [50] and references therein), because the NP contributions from scalars H + , H 0 , A can be significantly canceled out by their quasi-degenerate masses in the small λ 5 region.…”

“…It can be seen that the tightest constraint comes from the observable ∆M d due to the updated SM prediction [51][52][53][54]. As a consequence, an O(1) κ t is only allowed by pushing the charged-Higgs mass to TeV scales [50].…”

Likelihood analysis of the flavour anomalies and g – 2 in the general two Higgs doublet model

“…5 A second Higgs doublet has been examined as a way to explain the muon g − 2 anomaly. In the Type-X [18][19][20][21][22][23][24][25][26][27][28][29][30][31] and Flavour-Aligned [32][33][34][35][36][37] versions of the THDM the contributions from two-loop diagrams are dominant in most of the parameter space thanks to mechanisms also available in the GTHDM. Additionally, with LFV, the one-loop diagrams can receive a chirality flip enhancement from including the tau lepton in the diagram loop, as was investigated by [38][39][40][41][43][44][45][46], however they only examined muon g − 2 contributions at the one-loop level.…”

Electron and muon magnetic moments and implications for dark matter and model characterisation in non-universal U(1)′ supersymmetric models

“…Such a discrepancy does not lead to a numerical deviation only, but it also indicates that a mechanism must be implemented in BSM models which breaks lepton universality of the SM so that ∆a e /∆a µ = (−14)m 2 e /m 2 µ as experimentally established. Numerous studies resolving the muon g − 2 anomaly exist within a variety of BSM models , while there also are (fewer) studies which attempt to provide a consistent description of both deviations [61][62][63][64][65][66][67][68].…”