Non Minimal Higgs

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Signal to background interference in pp -> tH( -)-> tW( - )b(b)over-bar at the LHC Run II

Publication . Arhrib, Abdesslam; Benbrik, Rachid; Moretti, Stefano; Santos, Rui; Sharma, Pankaj

We investigate in the Large Hadron Collider (LHC) environment the possibility that sizeable interference effects between a heavy charged Higgs boson signal produced via bg -> tH(-) (+c.c.) scattering and decaying via H--> W(-)A -> W- b(b)over-bar (+c.c.) and the irreducible background given by bg -> tW(-) b(b)over-bar topologies could spoil current search approaches where the former and latter channels are treated separately. The rationale for this comes from the fact that a heavy charged Higgs state can have a large width, which can also happen for the CP-odd neutral Higgs state emerging in the ensuing decays, which in turn enables such interferences. We conclude that effects are very significant, both at the inclusive and exclusive level (i.e., both before and after H-+/- selection cuts arc enforced, respectively) and typically of a destructive nature. This, therefore, implies that currently established LHC reaches for heavy charged Higgs bosons require some level of resealing. However, this is possible a posteriori, as the aforementioned H-+/- selection cuts shape the interference contributions at the differential level in a way similar to that of the isolated H-+/- signal, so there is no need to reassess the efficiency of the individual cuts. We show such effects quantitatively by borrowing benchmark points from different Yukawa types of a 2-Higgs doublet model parameter space for H-+/- values starting from around 200 GeV.

2018-04-27Journal article

Open access

Signal versus background interference in H+ → t¯b signals for MSSM benchmark scenarios

Publication . Arhrib, Abdesslam; Azevedo, Duarte; Benbrik, Rachid; Harouiz, Hicham; Moretti, Stefano; Patrick, Riley; Santos, Rui

In this paper, we investigate sizeable interference effects between a heavy charged Higgs boson signal produced dominantly via gg -> tbH- (+ c.c.) followed by the decay H--> bt (+ c.c.) and the irreducible background given by pp -> ttbb topologies at the Large Hadron Collider (LHC). We show that it may be possible that such effects could spoil current H-+/- searches where signal and background are normally treated separately. The reason for this is that a heavy charged Higgs boson can have a large total width, in turn enabling such interferences, altogether leading to potentially very significant alterations, both at the inclusive and exclusive level, of the yield induced by the signal alone. This therefore implies that currently established LHC searches for such wide charged Higgs bosons might require modifications. We show such effects quantitatively using two different benchmark configurations of the minimal realisation of Supersymmetry, wherein such H-+/- states naturally exist. However, on the basis of the limited computing resources available, we are unable to always bring the statistical error down to a level where all such interference effects are unequivocal, so that we advocate dedicated experimental analyses to confirm this with higher statistics data samples.

2020-10-30Journal article

Open access

P -even, C P-violating signals in scalar-mediated processes

Publication . Haber, Howard E.; Keus, Venus; Santos, Rui

Most studies of Higgs sector CP violation focus on the detection of CP-violating neutral Higgs-fermion Yukawa couplings, which yield P-odd, CP-violating phenomena. There is some literature on purely bosonic signatures of Higgs sector CP violation, where the simultaneous observation of three processes (suitably chosen) constitutes a signal of P-even CP violation. However, in the examples previously analyzed, some of the processes are strongly suppressed in the approximate Higgs alignment limit (corresponding to the existence of a Standard Model-like Higgs boson as suggested by LHC data), in which case the proposed CP-violating signals are difficult to observe in practice. In this paper, we extend the existing literature by examining processes that do not vanish in the Higgs alignment limit and whose simultaneous observation would provide unambiguous evidence for scalar-mediated P-even CP violation. We assess the discovery potential of such signals at various future multi-TeV lepton (and γγ) colliders. The potential for detecting loop-induced P-even, CP-violating phenomena is also considered.

2022-11Journal article

Open access