scholarly journals Review of physics results from the Tevatron: Higgs boson physics

2015 ◽  
Vol 30 (06) ◽  
pp. 1541006 ◽  
Author(s):  
Thomas R. Junk ◽  
Aurelio Juste
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Vector Boson ◽  
Branching Ratio ◽  
Gluon Fusion ◽  
Mass Range ◽  
Higgs Bosons ◽  
Boson Mass ◽  
Decay Modes ◽  
The Standard Model

We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DØ. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV < mH < 200 GeV in all main production modes at the Tevatron: gluon–gluon fusion, WH and ZH associated production, vector boson fusion, and [Formula: see text] production, and in five main decay modes: [Formula: see text], H→τ+τ-, H→WW(*), H→ZZ(*) and H→γγ. An excess of events was seen in the [Formula: see text] searches consistent with a Standard Model Higgs boson with a mass in the range 115 GeV < mH < 135 GeV . Assuming a Higgs boson mass of mH = 125 GeV , studies of Higgs boson properties were performed, including measurements of the product of the cross section times the branching ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of 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.

HIGGS BOSON DISCOVERY POTENTIAL BEYOND THE MINIMAL STANDARD MODEL

1994 ◽  
Vol 09 (11) ◽  
pp. 1747-1785 ◽  
Author(s):  
ANDRÉ SOPCZAK
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Mass Parameter ◽  
Mass Range ◽  
Higgs Bosons ◽  
The Standard Model ◽  
Charged Higgs ◽  
Discovery Potential ◽  
Decisive Test ◽  
Minimal Standard

Detailed studies of neutral and charged Higgs boson pair production with full statistic detector simulations around [Formula: see text] with 500 pb−1 are presented in the context of a review of the Higgs boson discovery potential at LEP200. Already in the first phase of LEP200, a significant increase of the mass parameter space compared to LEP1 for the discovery of nonminimal Higgs bosons will be possible, while the mass range for the discovery of the minimal Standard Model Higgs boson will increase only marginally. The requirements for a decisive test of the Minimal Supersymmetric extension of the Standard Model (MSSM) at a later stage of LEP200 are discussed. A sensitivity mass range is given for charged Higgs bosons.

scholarly journals HIGGS SEARCHES AT THE TEVATRON

2010 ◽  
Vol 25 (27n28) ◽  
pp. 5097-5104
Author(s):  
◽  
KAZUHIRO YAMAMOTO
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Section ◽  
Mass Range ◽  
Higgs Bosons ◽  
Beyond The Standard Model ◽  
Standard Model Higgs Boson ◽  
Significant Excess ◽  
Proton Antiproton ◽  
The Standard Model

We present the latest results on searches for the standard and beyond-the-standard model Higgs bosons in proton-antiproton collisions at [Formula: see text] by the CDF and DØ experiments at the Fermilab Tevatron. No significant excess is observed above the expected background, and the cross section limits for the Higgs bosons are calculated. It is noticed that the standard model Higgs boson in the mass range 163 – 166 GeV/c2 is excluded at the 95% C.L.

scholarly journals The upgraded ATLAS and CMS detectors and their physics capabilities

2015 ◽  
Vol 373 (2032) ◽  
pp. 20140046 ◽  
Author(s):  
Pippa S. Wells
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Particle Physics ◽  
Higgs Bosons ◽  
Full Potential ◽  
Beyond The Standard Model ◽  
High Luminosity ◽  
Decay Modes ◽  
Boson Pair Production ◽  
The Standard Model

The update of the European Strategy for Particle Physics from 2013 states that Europe's top priority should be the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with a view to collecting 10 times more data than in the initial design. The plans for upgrading the ATLAS and CMS detectors so as to maintain their performance and meet the challenges of increasing luminosity are presented here. A cornerstone of the physics programme is to measure the properties of the 125 GeV Higgs boson with the highest possible precision, to test its consistency with the Standard Model. The high-luminosity data will allow precise measurements of the dominant production and decay modes, and offer the possibility of observing rare modes including Higgs boson pair production. Direct and indirect searches for additional Higgs bosons beyond the Standard Model will also continue.

scholarly journals HIGGS BOSON SEARCHES AT HADRON COLLIDERS

2005 ◽  
Vol 20 (12) ◽  
pp. 2523-2602 ◽  
Author(s):  
VOLKER BÜSCHER ◽  
KARL JAKOBS
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Vector Boson ◽  
Hadron Collider ◽  
Mass Range ◽  
Higgs Bosons ◽  
Standard Model Higgs Boson ◽  
Detector Performance ◽  
Discovery Potential ◽  
Fusion Mode

The investigation of the dynamics responsible for electroweak symmetry breaking is one of the prime tasks of experiments at present and future colliders. Experiments at the Tevatron [Formula: see text] Collider and at the CERN Large Hadron Collider (LHC) must be able to discover a Standard Model Higgs boson over the full mass range as well as Higgs bosons in extended models. In this review, the discovery potential for the Standard Model Higgs boson and for Higgs bosons in the Minimal Supersymmetric extension is summarized. Emphasis is put on those studies which have been performed recently within the experimental collaborations using a realistic simulation of the detector performance. This includes a discussion of the search for Higgs bosons using the vector boson fusion mode at the LHC, a discussion of the measurement of Higgs boson parameters as well as a detailed review of the MSSM sector for different benchmark scenarios. The Tevatron part of the review also contains a discussion of first physics results from data taken in the ongoing Run II.

scholarly journals FURTHER STUDIES OF HIGGS PROPERTIES AT AN ILC γγ COLLIDER

2013 ◽  
Vol 28 (18) ◽  
pp. 1350085 ◽  
Author(s):  
XIAO-GANG HE ◽  
SIAO-FONG LI ◽  
HSIU-HSIEN LIN
Keyword(s):  
Angular Distribution ◽  
Higgs Boson ◽  
Standard Model ◽  
Decay Mode ◽  
Branching Ratio ◽  
Current Data ◽  
Decay Modes ◽  
The Standard Model ◽  
Shell Production

Recently the ATLAS and CMS experiments at the LHC have found a Higgs-like boson h with a mass around 125 GeV from several decay modes. The decay mode h →γγ is one of the most important modes in studying whether h is actually the Standard Model (SM) Higgs boson. Current data indicate that h→γγ has a branching ratio larger than the SM prediction for h being identified as the SM Higgs boson. To decide whether the h discovered at the LHC is the SM Higgs boson, more data are needed. We study how γγ collider can help to provide some of the most important information about the Higgs boson properties. We show that a γγ collider can easily verify whether the enhanced h →γγ observed at the LHC hold. Different models can be tested by studying Higgs boson decay to γZ. Studying angular distribution of the γγ through on-shell production of h and its subsequent decays into a γγ pair can decide whether the Higgs-like boson h at the LHC is a spin-0 or a spin-2 boson.

scholarly journals Enhancing sensitivities to long-lived particles with high granularity calorimeters at the LHC

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Jia Liu ◽  
Zhen Liu ◽  
Lian-Tao Wang ◽  
Xiao-Ping Wang
Keyword(s):  
Standard Model ◽  
Vector Boson ◽  
Hadron Collider ◽  
Branching Ratio ◽  
Gluon Fusion ◽  
Vector Boson Fusion ◽  
Signal Model ◽  
Enhanced Sensitivity ◽  
Higgs Decay ◽  
The Standard Model

Abstract The search for long-lived particles (LLP) is an exciting physics opportunity in the upcoming runs of the Large Hadron Collider. In this paper, we focus on a new search strategy of using the High Granularity Calorimeter (HGCAL), part of the upgrade of the CMS detector, in such searches. In particular, we demonstrate that the high granularity of the calorimeter allows us to see “shower tracks” in the calorimeter, and can play a crucial role in identifying the signal and suppressing the background. We study the potential reach of the HGCAL using a signal model in which the Standard Model Higgs boson decays into a pair of LLPs, h → XX. After carefully estimating the Standard Model QCD and the misreconstructed fake-track backgrounds, we give the projected reach for both an existing vector boson fusion trigger and a novel displaced-track-based trigger. Our results show that the best reach for the Higgs decay branching ratio, BR(h → XX), in the vector boson fusion channel is about $$ \mathcal{O} $$ O (10−4) with lifetime cτX ∼ 0.1–1 meters, while for the gluon gluon fusion channel it is about $$ \mathcal{O} $$ O (10−5–10−6) for similar lifetimes. For longer lifetime cτX ∼ 103 meters, our search could probe BR(h → XX) down to a few ×10−4(10−2) in the gluon gluon fusion (vector boson fusion) channels, respectively. In comparison with these previous searches, our new search shows enhanced sensitivity in complementary regions of the LLP parameter space. We also comment on many improvements can be implemented to further improve our proposed search.

scholarly journals Search for π0 decays to invisible particles

2021 ◽  
Vol 2021 (2) ◽  
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.

scholarly journals Search for Heavy Higgs Bosons in Fermionic Decay Channels with CMS

2018 ◽  
Vol 46 ◽  
pp. 1860058
Author(s):  
Ye Chen
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Confidence Level ◽  
Higgs Bosons ◽  
Final States ◽  
Centre Of Mass ◽  
Decay Channels ◽  
Upper Limits ◽  
The Standard Model ◽  
Cms Detector

Latest results of searches for heavy Higgs bosons in fermionic final states are presented using the CMS detector at the LHC. Results are based on pp collision data collected at centre-of-mass energies of 8 and 13 TeV which have been interpreted according to different extensions of the Standard Model such as MSSM, 2HDM, and NMSSM. These searches look for evidence of other scalar or pseudoscalar bosons, in addition to the observed SM-like 125 GeV Higgs boson, and set 95% confidence level upper limits in fermionic final states and benchmark models explored. The talk reviews briefly the major results obtained by the CMS Collaboration during Run I, and presents the most recent searches performed during Run II.

scholarly journals The gravitational condensate of the higgs field

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Field ◽  
Higgs Bosons ◽  
Grand Unification ◽  
Gravitational Potential Energy ◽  
Mass Hierarchy ◽  
The Standard Model ◽  
Cell Condensation ◽  
The Difference

This paper analyses a method of producing the Higgs mass via the gravitational field. This approach has become very popular in recent years, as the consideration of other forces do not help in solving the problem of mass hierarchy. Not understand the difference between scales of the standard model and Grand unification theory. Here, we present a heuristic mechanism which eliminated this difference. The idea is that the density of the condensate of the Higgs is increased so that it is necessary to take into account self gravitational potential energy of the Higgs boson. The result is as follows. The mass of the Higgs is directly proportional to the cell density of the Higgs bosons. Or else the mass of the Higgs is inversely proportional to the cell volume, which is the Higgs boson in the condensate. The most interesting dimension of this cell condensation is equal to the scale of Grand unification. This formula naturally combines the scale of the standard model and Grand unification through gravitational condensation.

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