Higgs-boson masses in a supersymmetric extension of the standard model

We examine the Higgs sector of the minimal supersymmetric extension of the standard model. The requirement of perturbative unification combined with the recent LEP data on Higgs boson searches, excludes substantial regions of parameter space. We find that only 0.42 ≤ tan β≲0.76 and tan β≳1.30 are the allowed values for tan β=υ2/υ1. We also determine the absolute lower bound on the lightest Higgs mass to be ≈8 GeV. We conclude that improved lower bounds on the top quark mass and/or the standard model Higgs boson mass will impose yet more stringent constraints on the model. These results clearly favor tan β>1, in agreement with N=1 supergravity or superstring-inspired models.

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Search for π0 decays to invisible particles

Journal of High Energy Physics ◽

10.1007/jhep02(2021)201 ◽

2021 ◽

Vol 2021 (2) ◽

Cited By ~ 1

Author(s):

E. Cortina Gil ◽

◽

A. Kleimenova ◽

E. Minucci ◽

S. Padolski ◽

...

Keyword(s):

Higgs Boson ◽

Standard Model ◽

Confidence Level ◽

Branching Ratio ◽

Standard Model Higgs Boson ◽

Scalar Mixing ◽

Upper Limit ◽

Upper Limits ◽

The Standard Model ◽

Model Independent

Abstract The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 109 tagged π0 mesons from K+ → π+π0(γ), searching for the decay of the π0 to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4.4 × 10−9 is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K+ → π+X, where X is a particle escaping detection with mass in the range 0.110–0.155 GeV/c2 and rest lifetime greater than 100 ps. Model-dependent upper limits are obtained assuming X to be an axion-like particle with dominant fermion couplings or a dark scalar mixing with the Standard Model Higgs boson.

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Search for dark photons in Higgs boson production via vector boson fusion in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

Journal of High Energy Physics ◽

10.1007/jhep03(2021)011 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

A. M. Sirunyan ◽

◽

A. Tumasyan ◽

W. Adam ◽

T. Bergauer ◽

...

Keyword(s):

Higgs Boson ◽

Standard Model ◽

Confidence Level ◽

Branching Fraction ◽

Vector Boson ◽

Boson Mass ◽

Higgs Boson Mass ◽

Vector Boson Fusion ◽

Upper Limit ◽

The Standard Model

Abstract A search is presented for a Higgs boson that is produced via vector boson fusion and that decays to an undetected particle and an isolated photon. The search is performed by the CMS collaboration at the LHC, using a data set corresponding to an integrated luminosity of 130 fb−1, recorded at a center-of-mass energy of 13 TeV in 2016–2018. No significant excess of events above the expectation from the standard model background is found. The results are interpreted in the context of a theoretical model in which the undetected particle is a massless dark photon. An upper limit is set on the product of the cross section for production via vector boson fusion and the branching fraction for such a Higgs boson decay, as a function of the Higgs boson mass. For a Higgs boson mass of 125 GeV, assuming the standard model production rates, the observed (expected) 95% confidence level upper limit on the branching fraction is 3.5 (2.8)%. This is the first search for such decays in the vector boson fusion channel. Combination with a previous search for Higgs bosons produced in association with a Z boson results in an observed (expected) upper limit on the branching fraction of 2.9 (2.1)% at 95% confidence level.

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A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector

Physics Letters B ◽

10.1016/j.physletb.2020.135980 ◽

2021 ◽

Vol 812 ◽

pp. 135980

Author(s):

G. Aad ◽

B. Abbott ◽

D.C. Abbott ◽

A. Abed Abud ◽

K. Abeling ◽

...

Keyword(s):

Higgs Boson ◽

Standard Model ◽

Atlas Detector ◽

Standard Model Higgs Boson ◽

The Standard Model

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Indirect $$ \mathcal{CP} $$ probes of the Higgs-top-quark interaction: current LHC constraints and future opportunities

Journal of High Energy Physics ◽

10.1007/jhep11(2020)127 ◽

2020 ◽

Vol 2020 (11) ◽

Author(s):

Henning Bahl ◽

Philip Bechtle ◽

Sven Heinemeyer ◽

Judith Katzy ◽

Tobias Klingl ◽

...

Keyword(s):

Higgs Boson ◽

Standard Model ◽

Top Quark ◽

Decay Channel ◽

New Physics ◽

Current Data ◽

Quark Interaction ◽

The Standard Model ◽

Vector Bosons ◽

Selection Of

Abstract The $$ \mathcal{CP} $$ CP structure of the Higgs boson in its coupling to the particles of the Standard Model is amongst the most important Higgs boson properties which have not yet been constrained with high precision. In this study, all relevant inclusive and differential Higgs boson measurements from the ATLAS and CMS experiments are used to constrain the $$ \mathcal{CP} $$ CP -nature of the top-Yukawa interaction. The model dependence of the constraints is studied by successively allowing for new physics contributions to the couplings of the Higgs boson to massive vector bosons, to photons, and to gluons. In the most general case, we find that the current data still permits a significant $$ \mathcal{CP} $$ CP -odd component in the top-Yukawa coupling. Furthermore, we explore the prospects to further constrain the $$ \mathcal{CP} $$ CP properties of this coupling with future LHC data by determining tH production rates independently from possible accompanying variations of the $$ t\overline{t}H $$ t t ¯ H rate. This is achieved via a careful selection of discriminating observables. At the HL-LHC, we find that evidence for tH production at the Standard Model rate can be achieved in the Higgs to diphoton decay channel alone.

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