scholarly journals Exploration of Extended Higgs Sectors with Run-2 Proton–Proton Collision Data at the LHC

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2144
Author(s):  
Arnaud Ferrari ◽  
Nikolaos Rompotis
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Scalar Fields ◽  
Higgs Bosons ◽  
Proton Collision ◽  
Complex Scalar ◽  
Proton Proton ◽  
The Standard Model ◽  
Extended Higgs Sectors ◽  
Proton Proton Collision

One doublet of complex scalar fields is the minimal content of the Higgs sector in order to achieve spontaneous electroweak symmetry breaking and, in turn, to generate the masses of fundamental particles in the Standard Model. However, several theories beyond the Standard Model predict a nonminimal Higgs sector and introduce additional singlets, doublets or even higher-order weak isospin representations, thereby yielding additional Higgs bosons. With its high proton–proton collision energy (13 TeV during Run-2), the Large Hadron Collider opens a new window towards the exploration of extended Higgs sectors. This review article summarises the current state-of-the-art experimental results recently obtained in searches for new neutral and charged Higgs bosons with a partial or full Run-2 dataset.

scholarly journals Higgs searches beyond the Standard Model

2014 ◽  
Vol 31 ◽  
pp. 1460288 ◽  
Author(s):  
R. Mankel ◽  
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
Beyond The Standard Model ◽  
Model Interpretation ◽  
The Standard Model ◽  
Extended Higgs Sectors ◽  
Minimal Supersymmetric Model

While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Besides the Standard Model interpretation, various possibilities for extended Higgs sectors are being considered. The minimal supersymmetric extension (MSSM) features two Higgs doublets resulting in five physical Higgs bosons, which are subject to direct searches. Alternatively, more generic Two-Higgs Doublet models (2HDM) are used for the interpretation of results. The Next-to-Minimal Supersymmetric Model (NMSSM) has a more complex Higgs sector with seven physical states. Also exotic Higgs bosons decaying to invisible final states are considered. This article summarizes recent findings based on results from collider experiments.

scholarly journals Higgs searches beyond the Standard Model

2014 ◽  
Vol 29 (24) ◽  
pp. 1430057
Author(s):  
R. Mankel ◽  
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
Beyond The Standard Model ◽  
Model Interpretation ◽  
The Standard Model ◽  
Extended Higgs Sectors ◽  
Minimal Supersymmetric Model

While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Besides the Standard Model interpretation, various possibilities for extended Higgs sectors are being considered. The minimal supersymmetric extension (MSSM) features two Higgs doublets resulting in five physical Higgs bosons, which are subject to direct searches. Alternatively, more generic Two-Higgs Doublet models (2HDM) are used for the interpretation of results. The Next-to-Minimal Supersymmetric Model (NMSSM) has a more complex Higgs sector with seven physical states. Also exotic Higgs bosons decaying to invisible final states are considered. This article summarizes recent findings based on results from collider experiments.

scholarly journals Search for top squarks in events with a Higgs or Z boson using 139 fb$$^{-1}$$ of pp collision data at $$\sqrt{s}=13$$ TeV with the ATLAS detector

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Standard Model ◽  
Atlas Detector ◽  
Proton Collision ◽  
Top Squark ◽  
Proton Proton ◽  
Direct Production ◽  
Missing Transverse Momentum ◽  
The Standard Model ◽  
Model Predictions ◽  
Proton Proton Collision

AbstractThis paper presents a search for direct top squark pair production in events with missing transverse momentum plus either a pair of jets consistent with Standard Model Higgs boson decay into b-quarks or a same-flavour opposite-sign dilepton pair with an invariant mass consistent with a Z boson. The analysis is performed using the proton–proton collision data at $$\sqrt{s}=13$$ s = 13 TeV collected with the ATLAS detector during the LHC Run-2, corresponding to an integrated luminosity of 139 fb$$^{-1}$$ - 1 . No excess is observed in the data above the Standard Model predictions. The results are interpreted in simplified models featuring direct production of pairs of either the lighter top squark ($$\tilde{t}_1$$ t ~ 1 ) or the heavier top squark ($$\tilde{t}_2$$ t ~ 2 ), excluding at 95% confidence level $$\tilde{t}_1$$ t ~ 1 and $$\tilde{t}_2$$ t ~ 2 masses up to about 1220 and 875 GeV, respectively.

scholarly journals Measurements of the Higgs boson inclusive and differential fiducial cross sections in the 4$$\ell $$ decay channel at $$\sqrt{s}$$ = 13 TeV

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Sections ◽  
Decay Channel ◽  
Standard Model Prediction ◽  
Hadron Collider ◽  
Proton Collision ◽  
Proton Proton ◽  
The Standard Model ◽  
Proton Proton Collision

AbstractInclusive and differential fiducial cross sections of the Higgs boson are measured in the $$H \rightarrow ZZ^{*} \rightarrow 4\ell $$ H → Z Z ∗ → 4 ℓ ($$\ell = e,\mu $$ ℓ = e , μ ) decay channel. The results are based on proton−proton collision data produced at the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector from 2015 to 2018, equivalent to an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 . The inclusive fiducial cross section for the $$H \rightarrow ZZ^{*} \rightarrow 4\ell $$ H → Z Z ∗ → 4 ℓ process is measured to be $$\sigma _\mathrm {fid} = 3.28 \pm 0.32$$ σ fid = 3.28 ± 0.32  fb, in agreement with the Standard Model prediction of $$\sigma _\mathrm {fid, SM} = 3.41 \pm 0.18 $$ σ fid , SM = 3.41 ± 0.18  fb. Differential fiducial cross sections are measured for a variety of observables which are sensitive to the production and decay of the Higgs boson. All measurements are in agreement with the Standard Model predictions. The results are used to constrain anomalous Higgs boson interactions with Standard Model particles.

Review of combined measurements of Higgs boson production and decay using up to 80 fb−1 of proton–proton collision data at s = 13 TeV collected with the ATLAS experiment

2020 ◽  
pp. 2030023
Author(s):  
Hongtao Yang
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Vector Boson ◽  
Proton Collision ◽  
Boson Production ◽  
Proton Proton ◽  
Associated Production ◽  
The Standard Model ◽  
Proton Proton Collision ◽  
Combined Measurements

The combined measurements of Higgs boson production and decay are performed based on up to 80 fb[Formula: see text] of proton–proton collision data collected at [Formula: see text] = 13 TeV by the ATLAS detector. The overall signal strength, defined as measured signal yield divided by the Standard Model prediction, is [Formula: see text]. The inclusive and differential cross-sections of gluon–gluon fusion, vector-boson fusion, associated production with vector boson, and associated production with top quarks processes are also measured. The measurements are interpreted with leading-order motivated coupling strength modifiers. No significant deviations from the Standard Model predictions are observed.

scholarly journals Search for heavy neutral leptons in $$W^+\rightarrow \mu ^{+}\mu ^{\pm }\, \text {jet}$$ decays

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Mass Range ◽  
Lepton Number ◽  
Heavy Neutrino ◽  
Proton Collision ◽  
Final State ◽  
Data Set ◽  
Proton Proton ◽  
Upper Limits ◽  
The Standard Model ◽  
Proton Proton Collision

AbstractA search is performed for heavy neutrinos in the decay of a W boson into two muons and a jet. The data set corresponds to an integrated luminosity of approximately $$3.0\, \text {fb} ^{-1} $$ 3.0 fb - 1 of proton–proton collision data at centre-of-mass energies of 7 and $$8\, \text {TeV} $$ 8 TeV collected with the LHCb experiment. Both same-sign and opposite-sign muons in the final state are considered. Data are found to be consistent with the expected background. Upper limits on the coupling of a heavy neutrino with the Standard Model neutrino are set at $$95\%$$ 95 % confidence level in the heavy-neutrino mass range from 5 to $$50\, \text {GeV/}c^2 $$ 50 GeV/ c 2 . These are of the order of $$10^{-3}$$ 10 - 3 for lepton-number-conserving decays and of the order of $$10^{-4}$$ 10 - 4 for lepton-number-violating heavy-neutrino decays.

scholarly journals Searches for Direct Pair Production of Third Generation Squarks with the ATLAS Detector

2018 ◽  
Vol 46 ◽  
pp. 1860057
Author(s):  
Federico Meloni
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Higgs Sector ◽  
Fine Tuning ◽  
Proton Collision ◽  
Third Generation ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
Model Hierarchy ◽  
Generation Squarks

This document summarises recent ATLAS results for searches for third generation squarks using 36.1 [Formula: see text] of LHC proton-proton collision data collected at [Formula: see text] TeV. Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. Supersymmetry can naturally solve the Standard Model hierarchy problem by preventing a large fine-tuning in the Higgs sector: a typical natural SUSY spectrum contains light third generation squarks (stops and sbottoms). Both R-Parity conserving and R-Parity violating scenarios are considered. The searches involve final states including jets, missing transverse momentum, electrons or muons. Simplified models predicting pair production of third generation squarks have been excluded at 95% CL up to about one TeV in the most favourable scenarios.

HIGGS BOSONS

1990 ◽  
Vol 05 (26) ◽  
pp. 2087-2100 ◽  
Author(s):  
A. MÉNDEZ
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
The Standard Model ◽  
Doublet Model ◽  
Minimal Supersymmetric Model ◽  
Extended Higgs Sector

The main phenomenological aspects of the Higgs bosons are briefly reviewed in the context of the Standard Model and in models with an "extended" Higgs sector. Among the latter, special emphasis is made on the Two-Doublet Model and, particularly, the Minimal Supersymmetric Model.

scholarly journals Triple Higgs boson production at the Large Hadron Collider with Two Real Singlet scalars

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Andreas Papaefstathiou ◽  
Tania Robens ◽  
Gilberto Tetlalmatzi-Xolocotzi
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
Scalar Fields ◽  
Higgs Bosons ◽  
Final State ◽  
Quark Pairs ◽  
The Standard Model ◽  
Scalar Sector

Abstract We investigate the production of three Higgs bosons in the Two Real Singlet extension of the Standard Model, where the scalar sector is augmented by two additional real scalar fields which are singlets under the Standard Model gauge group. The model contains three neutral CP-even scalars, allowing for resonant production and asymmetric decay chains. We focus on the signature pp → h3→ h1h2→ h1h1h1, where we identify h3 as the heaviest scalar state, h2 as the second heaviest and the lightest, h1, as the Standard Model-like Higgs boson discovered by the Large Hadron Collider experiments. The dominant final state occurs when all three Higgs bosons decay to bottom-anti-bottom quark pairs, h1→$$ b\overline{b} $$ b b ¯ , leading to 6 b-jets. Taking into account all current theoretical and experimental constraints, we determine the discovery prospects for this channel in future runs of the Large Hadron Collider, as well as in the high-luminosity phase.

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