scholarly journals Probing top changing neutral Higgs couplings at colliders

2021 ◽  
Vol 36 (07) ◽  
pp. 2130006 ◽  
Author(s):  
Wei-Shu Hou ◽  
Tanmoy Modak

The [Formula: see text] boson, discovered only in 2012, is lower than the top quark in mass, hence [Formula: see text] search commenced immediately thereafter, with current limits at the per mille level and improving. As the [Formula: see text] rate vanishes with the [Formula: see text]-[Formula: see text] mixing angle [Formula: see text], we briefly review the collider probes of the top changing [Formula: see text] coupling [Formula: see text] of the exotic [Formula: see text]-even/odd Higgs bosons [Formula: see text]. Together with an extra top conserving [Formula: see text] coupling [Formula: see text], one has an enhanced [Formula: see text] coupling alongside the familiar [Formula: see text] coupling, where [Formula: see text] is the charged Higgs boson. The main processes we advocate are [Formula: see text], [Formula: see text] (same-sign top and triple-top), and [Formula: see text]. We also discuss some related processes such as [Formula: see text], [Formula: see text] that depend on [Formula: see text] being nonzero, comment briefly on [Formula: see text] resonant production and touch upon the [Formula: see text] coupling.

2020 ◽  
Vol 35 (15n16) ◽  
pp. 2041011 ◽  
Author(s):  
Abdesslam Arhrib ◽  
Adil Jueid ◽  
Stefano Moretti

We study the production of a heavy charged Higgs boson at the Large Hadron Collider (LHC) in [Formula: see text] within a 2-Higgs Doublet Model (2HDM). The chiral structure of the [Formula: see text] 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.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
◽  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  

Abstract A search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb−1 of proton-proton collisions at $$ \sqrt{s} $$ s = 13 TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, pp → tbH+ → tbtb, is explored in the H+ mass range from 200 to 2000 GeV using final states with jets and one electron or muon. Events are categorised according to the multiplicity of jets and b-tagged jets, and multivariate analysis techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching ratio of a charged Higgs boson as a function of its mass; they range from 3.6 pb at 200 GeV to 0.036 pb at 2000 GeV at 95% confidence level. The results are interpreted in the hMSSM and $$ {M}_h^{125} $$ M h 125 scenarios.


2017 ◽  
Vol 32 (23n24) ◽  
pp. 1750145 ◽  
Author(s):  
A. G. Akeroyd ◽  
Stefano Moretti ◽  
Kei Yagyu ◽  
Emine Yildirim

The constraints from the measurements of the [Formula: see text] decay rate on the parameter space of 3-Higgs Doublet Models (3HDMs), where all the doublets have nonzero vacuum expectation values, are studied at the next-to-leading order in QCD. In order to naturally avoid the presence of flavour changing neutral currents at the tree level, we impose two softly-broken discrete [Formula: see text] symmetries. This gives rise to five independent types of 3HDMs that differ in their Yukawa couplings. We show that in all these 3HDMs (including the case of type-II-like Yukawa interactions) both masses of the two charged Higgs bosons [Formula: see text] and [Formula: see text] can be smaller than the top mass [Formula: see text] while complying with the constraints from [Formula: see text]. As an interesting phenomenological consequence, the branching ratios of the charged Higgs bosons decay into the [Formula: see text] final states can be as large as [Formula: see text] when their masses are taken to be below [Formula: see text] in two of the five 3HDMs (named as Type-Y and Type-Z). This light charged Higgs boson scenario provides a hallmark 3HDM signature that cannot be realised in [Formula: see text] symmetric 2-Higgs doublet models. We find that in the Type-Y and Type-Z 3HDMs the scenario with [Formula: see text], [Formula: see text] is ruled out by the direct searches at the LHC, but in the Type-Y 3HDM [Formula: see text] and [Formula: see text] is allowed by [Formula: see text] and direct searches at LEP2, Tevatron and LHC due to the reduced sensitivity of these searches to the degenerate case [Formula: see text]. The cases where only one or both charged Higgs bosons are above the top quark mass are also naturally allowed in the both Type-Y and Type-Z 3HDMs.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Henning Bahl ◽  
Tim Stefaniak ◽  
Jonas Wittbrodt

Abstract The presence of charged Higgs bosons is a generic prediction of multiplet extensions of the Standard Model (SM) Higgs sector. Focusing on the Two-Higgs-Doublet-Model (2HDM) with type I and lepton-specific Yukawa sectors, we discuss the charged Higgs boson collider phenomenology in the theoretically and experimentally viable parameter space. While almost all existing experimental searches at the LHC target the fermionic decays of charged Higgs bosons, we point out that the bosonic decay channels — especially the decay into a non-SM-like Higgs boson and a W boson — often dominate over the fermionic channels. Moreover, we revisit two genuine BSM effects on the properties of the discovered Higgs boson — the charged Higgs contribution to the diphoton rate and the Higgs decay to two light Higgs bosons — and their implication for the charged Higgs boson phenomenology. As main result of the present paper, we propose five two-dimensional benchmark scenarios with distinct phenomenological features in order to facilitate the design of dedicated LHC searches for charged Higgs bosons decaying into a W boson and a light, non-SM-like Higgs boson.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Junxing Pan ◽  
Jung-Hsin Chen ◽  
Xiao-Gang He ◽  
Gang Li ◽  
Jhih-Ying Su

AbstractIn this work, we study the potential of searching for triply charged Higgs boson originating from a complex Higgs quadruplet in the final state with at least three same-sign leptons. A detailed collider analysis of the SM backgrounds and signals is performed at a 100 TeV pp collider for the triply charged Higgs boson mass below 1 TeV and the Higgs quadruplet vacuum expectation value $$v_\Delta $$ v Δ ranging from $$1.5\times 10^{-9}~\text {GeV}$$ 1.5 × 10 - 9 GeV to $$1.3~\text {GeV}$$ 1.3 GeV and the mass splitting $$\Delta m$$ Δ m between the nearby states of the Higgs quadruplet satisfying $$|\Delta m|\lesssim 30~\text {GeV}$$ | Δ m | ≲ 30 GeV . About $$100~\text {fb}^{-1}$$ 100 fb - 1 of data are required at most for $$5\sigma $$ 5 σ discovery. We also revisit the sensitivity at the Large Hadron Collider (LHC) and find that $$5\sigma $$ 5 σ discovery of the triply charged Higgs boson below 1 TeV can be reached for a relatively small $$v_\Delta $$ v Δ . For example, if $$v_\Delta =10^{-6}~\text {GeV}$$ v Δ = 10 - 6 GeV and $$\Delta m=0$$ Δ m = 0 , the integrated luminosity of $$330~\text {fb}^{-1}$$ 330 fb - 1 is needed. But for a relatively large $$v_\Delta $$ v Δ , i.e., $$v_\Delta \gtrsim 10^{-3}~\text {GeV}$$ v Δ ≳ 10 - 3 GeV , the triply charged Higgs boson above about 800 GeV cannot be discovered even in the high-luminosity LHC era. For $$\Delta m>0$$ Δ m > 0 , the cascade decays are open and the sensitivity can be improved depending on the value of $$v_\Delta $$ v Δ .


1992 ◽  
Vol 285 (1-2) ◽  
pp. 137-140 ◽  
Author(s):  
Chong Sheng Li ◽  
Yan Sheng Wei ◽  
Jin Min Yang

2019 ◽  
Vol 34 (28) ◽  
pp. 1950230
Author(s):  
Zhaoxia Heng ◽  
Lin Guo ◽  
Pengqiang Sun ◽  
Wei Wei

Charged Higgs boson is a crucial prediction of new physics beyond the SM. In this work, we perform a comprehensive scan over the parameter space of NMSSM considering various experimental constraints including the direct search limits from the 13 TeV LHC, and consider the scenario that the next-to-lightest CP-even Higgs boson is SM-like. We find that the masses of charged Higgs bosons can be as light as 350 GeV, the lightest CP-even Higgs boson [Formula: see text] is predominantly singlet and can be as light as 48 GeV, and the lightest CP-odd Higgs boson [Formula: see text] is also singlet-dominated and can be as light as 82 GeV. The charged Higgs bosons mainly decay to [Formula: see text] or [Formula: see text], but the branching ratio of the exotic decays [Formula: see text] and [Formula: see text] can maximally reach 20% and 11%, respectively, which can be used to distinguish the NMSSM from MSSM. Such a heavy charged Higgs boson is inaccessible at the 13 TeV LHC with a luminosity of 36.1 fb[Formula: see text] and its detection needs higher energy and/or higher luminosity.


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