75 research outputs found
Top quark polarization as a probe of charged Higgs bosons
No full textWe study the production and decay of a heavy charged Higgs boson in the bg→tH- and H-→bt processes at the Large Hadron Collider (LHC). We show that the chiral structure of the H-tb vertex entering both stages is sensitive to the underlying Higgs mechanism of electroweak symmetry breaking (EWSB) and we specifically demonstrate that one could distinguish between two popular realizations of a 2-Higgs doublet model (2HDM) embedding a new H± state, i.e., those with Type-I and -Y Yukawa couplings. The chiral structure of such a vertex, which is different in the two cases, in turn triggers a particular spin state of the top quark which is then transmitted to its decay products. Hence, both inclusive rates and exclusive observables can be used to extract the presence of such a charged Higgs boson state in LHC data.</p
Searching for heavy charged Higgs bosons through top quark polarization
No full textWe study the production of a heavy charged Higgs boson at the Large Hadron Collider (LHC) in gb→H−t within a 2-Higgs Doublet Model (2HDM). The chiral structure of the H+t̄ b coupling can trigger a particular spin state of the top quark produced in the decay of a charged Higgs boson and, therefore, is sensitive to the underlying mechanism of the Electroweak Symmetry Breaking (EWSB). Taking two benchmark models (2HDM type-I and 2HDM type-Y) as an example, we show that inclusive rates, differential distributions and forward–backward asymmetries of the top quark’s decay products can be used to search for heavy charged Higgs bosons and also as model discriminators
Large Hadron Collider signatures of exotic Vector-Like quarks within the 2-Higgs Doublet Model Type-II
No full textWe study the decay of the exotic Vector-Like Quarks (VLQs) X and Y, with 5/3 and −4/3 units of electric charge, respectively, within the 2-Higgs Doublet Model (2HDM). Building on our previous studies of Vector-Like Top and Bottom (VLT and VLB) quarks, we now investigate the characteristics of X and Y in the alignment limit of a Type-II Yukawa structure and show that, in the framework of such a 2HDM, one can have large non-Standard Model (SM) decay rates of the X andY states. Our analysis focuses on their potential detection at the Large Hadron Collider (LHC), based on their pair production followed by a variety of both SM and non-SM decay patterns. In order to distinguish between doublet and triplet representations of the VLQs X and Y, we uncover specific signatures that can provide insights into this particular architecture of Beyond the SM (BSM) physics
Anatomy of Vector-Like Bottom-Quark Models in the alignment limit of the 2-Higgs Doublet Model Type-II
No full textExpanding upon our ongoing investigation of Vector-Like Quark (VLQ) phenomenology within a 2-Higgs Doublet Model (2HDM) framework, in this paper, we complement a previous one dedicated to Vector-Like Top-quarks (VLTs) by studying Vector-Like Bottom-quarks (VLBs), specifically focusing on their behavior in the alignment limit of a Type-II Yukawa structure. We examine the potential for detecting VLBs at the Large Hadron Collider (LHC) and analyze their decay signatures, encompassing both Standard Model (SM) processes and exotic decays. The objective is to differentiate among singlet, doublet, and triplet configurations of VLBs by identifying distinct decay patterns, thereby providing insights into the structure of Beyond the SM (BSM) physics
Signal to background interference in pp →tH- →tW-b b at the LHC Run II
No full textWe 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-bb (+c.c.) and the irreducible background given by bg→tW-bb 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 are 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 rescaling. 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.</p
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