scholarly journals PRECISION MASS DETERMINATION OF THE HIGGS BOSON AT PHOTON–PHOTON COLLIDERS

2000 ◽  
Vol 15 (16) ◽  
pp. 2605-2611 ◽  
Author(s):  
TOMOMI OHGAKI
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Mass ◽  
Statistical Error ◽  
High Energy ◽  
Boson Mass ◽  
Total Width ◽  
Mass Determination ◽  
The Standard Model

We demonstrate a measurement of the Higgs boson mass by the method of energy scanning at photon–photon colliders, using the high energy edge of the photon spectrum. With an integrated luminosity of 50 fb-1 it is possible to measure the standard model Higgs mass to within 110 MeV in photon–photon collisions for mh=100 GeV. As for the total width of the Higgs boson, the statistical error ΔΓh/Γh SM=0.06 is expected for mh=100 GeV, if both Γ(h→γγ) and [Formula: see text] are fixed at the predicted standard model value.

NEW BOUNDS ON THE HIGGS SECTOR OF MINIMAL SUSY

1990 ◽  
Vol 05 (16) ◽  
pp. 1259-1264 ◽  
Author(s):  
JORGE L. LOPEZ ◽  
D.V. NANOPOULOS
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Quark Mass ◽  
Higgs Mass ◽  
Higgs Sector ◽  
Boson Mass ◽  
Top Quark Mass ◽  
Supersymmetric Extension ◽  
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.

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

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.

scholarly journals Higgs boson mass bounds in the Standard Model with type III and type I seesaw

2008 ◽  
Vol 668 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Ilia Gogoladze ◽  
Nobuchika Okada ◽  
Qaisar Shafi
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Boson Mass ◽  
Type I ◽  
Higgs Boson Mass ◽  
Type Iii ◽  
The Standard Model

scholarly journals Theory requirements for SM Higgs and EW precision physics at the FCC-ee

2021 ◽  
Vol 136 (9) ◽  
Author(s):  
S. Heinemeyer ◽  
S. Jadach ◽  
J. Reuter
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
High Precision ◽  
Boson Mass ◽  
Experimental Measurements ◽  
Mixing Angle ◽  
The Standard Model ◽  
The Status ◽  
Precision Observables ◽  
Electroweak Precision

AbstractHigh-precision experimental measurements of the properties of the Higgs boson at $$\sim 125$$ ∼ 125  GeV as well as electroweak precision observables such as the W-boson mass or the effective weak leptonic mixing angle are expected at future $$e^+e^-$$ e + e - colliders such as the FCC-ee. This high anticipated precision has to be matched with theory predictions for the measured quantities at the same level of accuracy. We briefly summarize the status of these predictions within the standard model and of the tools that are used for their determination. We outline how the theory predictions will have to be improved in order to reach the required accuracy, and also comment on the simulation frameworks for the Higgs and EW precision program.

Upper Bound on the Higgs-Boson Mass in the Standard Model

1988 ◽  
Vol 61 (6) ◽  
pp. 678-681 ◽  
Author(s):  
Julius Kuti ◽  
Lee Lin ◽  
Yue Shen
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Upper Bound ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
The Standard Model

scholarly journals Presymmetry in the Standard Model with adulterated Dirac neutrinos

2015 ◽  
Vol 30 (31) ◽  
pp. 1550160 ◽  
Author(s):  
Ernesto A. Matute
Keyword(s):  
Standard Model ◽  
High Energy ◽  
New Physics ◽  
Boson Mass ◽  
Effective Theory ◽  
Type I ◽  
Electroweak Symmetry ◽  
Seesaw Mechanism ◽  
Left Handed ◽  
The Standard Model

Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the ’t Hooft’s naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

scholarly journals Z-DECAYS TO b QUARKS AND THE HIGGS BOSON MASS

1999 ◽  
Vol 14 (26) ◽  
pp. 1815-1827 ◽  
Author(s):  
J. H. FIELD
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Standard Model Prediction ◽  
Strong Dependence ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
The Standard Model ◽  
200 Gev ◽  
B Quark

A model independent analysis of the most recent averages of precision electroweak data from LEP and SLD finds a 3σ deviation of the parameter Ab from the standard model prediction. The fitted value of mH shows a strong dependence on the inclusion or exclusion of b quark data, and the standard model fits have poor confidence levels of a few percent when the latter are included. The good fits obtained to lepton data, c quark data and the directly measured top quark mass, give [Formula: see text] and indicate that the Higgs boson mass is most likely less than 200 GeV.

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