Double fermiophobic Higgs boson production at the CERN LHC and a linear collider

Abstract

We consider the phenomenology of a fermiophobic Higgs boson (h f ) at the Large Hadron Collider (LHC) and a e + e − Linear Collider (LC). At both machines the standard production mechanisms which rely on the coupling h f V V (V = W ± , Z) can be very suppressed at large tan β. In such cases the complementary channels pp → H ± h f , A 0 h f and e + e − → A 0 h f offer promising cross-sections. Together with the potentially large branching ratios for H ± → h f W * and A 0 → h f Z * , these mechanisms would give rise to double h f production, leading to signatures of γγγγ, γγV V and V V V V .

Multi-photon signatures at the Fermilab Tevatron

“…Consequently, this scenario would give rise to double h f production, with subsequent decay of h f h f → γγγγ, V V γγ and V V V V . For light h f (m h f < ∼ 90 GeV), the signal γγγγ would dominate, as discussed in [24] at LEP, in [22] for the Tevatron Run II and [23] at the LHC and a Linear Collider. More specifically, the multi-photon signature arises in the portion of the parameters space where m h f < ∼ 90 GeV, m H ± < ∼ 200 GeV, and tan β > 1 in the 2HDM Model I framework.…”

“…The larger coefficient for the V H To date complementary mechanisms have not been considered in the direct fermiophobic Higgs searches at the Tevatron. As emphasized in [22], [23] a more complete search strategy for h f at hadron colliders must include such production processes in order to probe the scenario of fermiophobic Higgs bosons with a suppressed coupling h f V V . In the HTM one expects H 0 ′ 1 to be the lightest Higgs boson for small sin θ H , which further motivates a search in the complementary channel qq…”

“…An alternative production mechanism which also depends on the complementary h f V H coupling is the process qq ′ → H ± h f [22], [23]. Such a mechanism is exclusive to a hadron collider, and can offer promising rates at the Tevatron Run II provided that H ± is not too far above its present mass bound m H ± > 90 GeV.…”

Light signals from a lighter Higgs

“…Other interesting channels are HH + production through an off-shell W boson [17][18][19][20][21] and ZH production through an off-shell A 0 [22]. The couplings of the 125 GeV Higgs boson are constrained to lie close to SM values [23] which means that |s δ | 0.4.…”

Flavor physics of leptons and dipole moments

“…A very well known fermiophobic Higgs boson may arise in such model [579][580][581] . Another example is the Inert Doublet Model, with an unbroken discrete Z 2 symmetry which forbids one Higgs doublet to couple to fermions and to get a non-zero VEV [582,583].…”