scholarly journals Higgs boson mass in the standard model at two-loop order and beyond

2014 ◽  
Vol 90 (7) ◽  
Author(s):  
Stephen P. Martin ◽  
David G. Robertson
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Loop Order ◽  
The Standard Model

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

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 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.

scholarly journals THE LEE-WICK STANDARD MODEL

2010 ◽  
Vol 25 (02n03) ◽  
pp. 587-596 ◽  
Author(s):  
MARK B. WISE
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Recent Work ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Negative Norm ◽  
Higher Derivative ◽  
The Standard Model ◽  
Higher Derivatives

This article reviews some recent work on a version of the standard model (the Lee-Wick standard model) that contains higher derivative kinetic terms that improve the convergence of loop diagrams removing the quadratic divergence in the Higgs boson mass. Naively higher derivative theories of this type are not acceptable since the higher derivative terms either cause instabilities (from negative energies) or a loss of unitarity (from negative norm states). Lee and Wick provided an interpretation for such theories arguing that theories with higher derivative kinetic terms can be unitary and stable if the states associated with the massive propagator poles, that arise from the higher derivatives, have widths and hence decay and are not in the spectrum of the theory.

scholarly journals Vacuum stability of asymptotically safe two Higgs doublet models

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Peter Schuh
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Fixed Points ◽  
Higgs Doublet ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Type Ii ◽  
Vacuum Stability ◽  
The Standard Model ◽  
Two Higgs Doublet Models

Abstract We study different types of Two Higgs Doublet Models (2HDMs) under the assumption that all quartic couplings’ beta functions vanish simultaneously at the Planck scale. The Standard Model seems to display this property almost accidentally, because the Higgs boson mass is close to 125 GeV. This also ties closely into the question of whether the theory is stable or metastable. We investigate if such “fixed points” can exist in various $${\mathbb {Z}}_2$$Z2-symmetric 2HDM subclasses, and if the theories that meet these conditions are phenomenologically viable, as well as vacuum stable. We find that the fixed point condition drastically reduces the parameter space of 2HDM theories, but can be met. Fixed points can only exist in type II and type Y models, in regions of large tan$$\beta $$β, and they are only compatible with all existing experimental bounds if the $${\mathbb {Z}}_2$$Z2-symmetry is at least softly broken, with a soft breaking parameter of at least $$M_{12}>$$M12> 70 GeV (380 GeV) for type Y (type II) models. The allowed region falls into the alignment limit, with the mixing angle combination $$|\alpha - \beta | \approx \frac{\pi }{2}$$|α-β|≈π2. While there are both vacuum-stable and vacuum-unstable solutions, only the vacuum-unstable ones really agree with Standard-Model-like CP-even Higgs boson mass values of 125 GeV. The vacuum-stable solutions favour slightly higher values. While scenarios of asymptotically safe 2HDM exist, they cannot improve over the Standard Model regarding the question of vacuum stability.

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