Flavor changing heavy Higgs interactions with leptons at hadron colliders

Abstract

In a general two Higgs doublet model, we study flavor changing neutral Higgs (FCNH) decays into leptons at hadron colliders, pp → φ 0 → τ ∓ µ ± +X, where φ 0 could be a CP-even scalar (h 0 , H 0 ) or a CP-odd pseudoscalar (A 0 ). The light Higgs boson h 0 is found to resemble closely the Standard Model Higgs boson at the Large Hadron Collider. In the alignment limit of cos(β − α) ∼ = 0 for h 0 -H 0 mixing, FCNH couplings of h 0 are naturally suppressed, but such couplings of the heavier H 0 , A 0 are sustained by sin(β − α) ≃ 1. We evaluate physics backgrounds from dominant processes with realistic acceptance cuts and tagging efficiencies. We find promising results for √ s = 14 TeV, which we extend further to √ s = 27 TeV and 100 TeV future pp colliders.

Decadal Mission for the New Physics Higgs/Flavor Era

“…( 23). This motivates the check with gg → H, A → τ µ search [80]. We find [120] that a recent result from CMS [121], using 36 fb −1 data at 13 TeV, already puts more stringent bound on the extra top Weinberg coupling ρ tt than from τ → µγ through the two-loop mechanism, which is quite interesting.…”

“…We have worked out e.g. gg → A, H → tc [60], τ µ [80]; cg → tA → tZH [54], where A → ZH is a weak decay; cg → tH → thh [81] and cg → bH + → bhW + [82], which depend on h-H mixing; or cg → bH + → bAW + [83]. For these and other works, we refer to our brief review [84] for discussion.…”

Enhanced B→μν¯ decay at tree level as probe of extra Yukawa couplings

“…We treat ρ τ µ more liberally, as argued above for |ρ τ µ | ∼ λ τ ∼ 0.01, since much larger ρ τ µ values have been considered only recently. The most relevant constraint comes from τ → µγ, where the two-loop mechanism constrains |ρ τ µ | 0.01 [32] for ρ tt ∼ 1, but weakens for weaker ρ tt . Finally, having |ρ τ µ | |ρ τ τ | ∼ λ τ is not unreasonable, just as |ρ tc | could be up to |ρ tt | ∼ λ t [33], where ρ tt and ρ tc provide two possible CP violating sources for electroweak baryogenesis, which strongly motivates g2HDM.…”

Charming Top Decays with a Flavor Changing Neutral Higgs Boson at Hadron Colliders

“…This could engender the rare decay t → ch 0 . The flavor changing heavy Higgs decays (H 0 → tc+tc [22] as well as H 0 → τμ +τ µ [32]) and FCNH top decay (t → ch 0 ) are complementary to search for new physics at the LHC. The coupling g tch is proportional to cos(β − α) while g Hτ µ and g Htc ∝ sin(β − α).…”