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

Abstract

We present a likelihood analysis of the general two Higgs doublet model, using the most important currently measured flavour observables, in view of the anomalies in charged current tree-level and neutral current one-loop rare decays of B mesons in b → clν and b → sµ + µ − transitions, respectively. We corroborate that the model explains the latter and it is able to simultaneously fit the experimental values of the R(D) charged current ratio at 1σ, but it can not accommodate the D * charmed meson observables R(D * ) and F L (D * ). We find that the fitted values for the angular observables in b → sµ + µ − transitions exhibit better agreement with the general two Higgs double model in comparison to the SM. We also make predictions for future collider observables BR(t → ch), BR(h → bs), BR(h → τ µ), BR(B s → τ + τ − ), BR(B + → K + τ + τ − ) and the flavour violating decays of the τ lepton, BR(τ → 3µ) and BR(τ → µγ). The model predicts values of BR(t → ch), BR(B s → τ + τ − ) and BR(B + → K + τ + τ − ) that are out of reach of future experiments, but its predictions for BR(h → bs) and BR(h → τ µ) are within the future sensitivity of the HL-LHC or the ILC. We also find that the predictions for the τ → 3µ and τ → µγ decays are well within the projected limits of the Belle II experiment. Finally, using the latest measurement of the Fermilab Muon g − 2 Collaboration, we performed a simultaneous fit to ∆a µ constrained by the charged anomalies, finding solutions at the 1σ level. Once the neutral anomalies are included, however, a simultaneous explanation is unfeasible.

Revival of $H^-$ interpretation of $R_{D^{(*)}}$ anomaly and closing low mass window

“…In the G2HDM there are 4 additional degrees of freedom, a CP even scalar (H), a CP odd scalar (A) and charged scalars (H ± ). Such an extension, however, can be dangerous since the additional scalars have flavor violating interactions even at tree level in general, the model had been attracting attentions in light of the discrepancy [13][14][15][16][17][18][19][20][21][22][23][24] since H − can contribute to B → D ( * ) τν process. The charged Higgs effect can be generally encoded in the low-energy effective Hamiltonian,…”

Searching for extra Higgs bosons via $pp\to H,A\to τμ, ττ$ at the Large Hadron Collider

“…The muon g − 2 anomaly can be explained in g2HDM by flavor violating ρ τ µ couplings, as discussed in Refs. [9][10][11]. The lepton flavor violating (LFV) ρ τ µ and ρ µτ couplings can drive h → τ µ, which can be of concern as the limit [12] B(h → τ µ) < 0.15 %,…”

Towards ruling out the charged Higgs interpretation of the $R_{D^{(*)}}$ anomaly

“…In this paper we investigate the LHC sensitivity to the low-mass charged Higgs H − interpretation of the anomaly focusing on a specific channel: final states with an energetic τ lepton that decays hadronically, large missing transverse momentum from an energetic neutrino, and an additional b-jet (pp → b + τ h + E miss T ). The model has widely been discussed in the literature [25][26][27][28][29][30][31][32][33][34][35], and recently been revisited in Ref. [36] since the constraint from B c → τν is significantly relaxed [23,24,37].…”