scholarly journals Leading Weak Corrections to the Production of Heavy Top Quarks at Hadron Colliders

1997 ◽  
Vol 12 (07) ◽  
pp. 1341-1372 ◽  
Author(s):  
Chung Kao ◽  
G. A. Ladinsky ◽  
C.-P. Yuan
Keyword(s):  
Higgs Boson ◽  
Parity Violation ◽  
Top Quark ◽  
Top Quarks ◽  
New Physics ◽  
Threshold Region ◽  
Hadron Colliders ◽  
Top Quark Mass ◽  
Quark Pairs ◽  
The Standard Model

We calculate the leading weak corrections at [Formula: see text] to the QCD production of heavy top quark pairs via [Formula: see text] at hadron colliders and compare them with the complete one-loop weak corrections. We find that these corrections dominate the threshold region for a heavy top quark if the Higgs boson is light. For a heavy Higgs boson, these corrections are generally small. The chromo-anapole form factor of the top quark and effects of parity violation are studied in the Standard Model (SM). The parity violation effect in [Formula: see text] from the SM weak corrections is found to be very small, so any observation of large parity violation in this process would indicate new physics. The polarization of the [Formula: see text] pairs is also discussed, including the effect that this has on proposed techniques for measuring the top quark mass.

scholarly journals Recent CMS results in top and Higgs physics

2017 ◽  
Vol 32 (29) ◽  
pp. 1730026
Author(s):  
Rebeca Gonzalez Suarez
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Large Scale ◽  
Top Quarks ◽  
Large Mass ◽  
New Physics ◽  
Higgs Bosons ◽  
Physics Program ◽  
The Standard Model

After the Higgs boson discovery in 2012, the investigation of its properties and compatibility with the Standard Model predictions is central to the physics program of the LHC experiments. Likewise, the study of the top quark is still relevant at the LHC, more than two decades after its discovery at the Tevatron. Top quarks and Higgs bosons are produced at the LHC on a large scale and share a deep connection based on the large mass of the top quark. Both particles provide an excellent laboratory in which to search for new physics: the measurement of their properties tests the foundations of the Standard Model; and they feature prominently in a variety of exotic signals. The coupling of the Higgs boson to the top quark, a fundamental Standard Model parameter, can only be measured directly in processes where the two particles are produced together. The production of a Higgs boson together with one or two top quarks is also sensitive to several exciting new physics effects. A brief overview of the current experimental status of top quark and Higgs boson physics is presented using results from the CMS Collaboration.

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

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.

scholarly journals HIGGS PARTICLES AT FUTURE HADRON AND ELECTRON-POSITRON COLLIDERS

1995 ◽  
Vol 10 (01) ◽  
pp. 1-63 ◽  
Author(s):  
A. DJOUADI
Keyword(s):  
Top Quark ◽  
Quark Mass ◽  
High Energy ◽  
High Energy Electron ◽  
Hadron Colliders ◽  
Top Quark Mass ◽  
Supersymmetric Extension ◽  
Fundamental Properties ◽  
Electron Positron ◽  
The Standard Model

The prospects for discovering Higgs particles and studying their fundamental properties at future high-energy electron-positron and hadron colliders are reviewed. Both the Standard Model Higgs boson and the Higgs particles of its minimal supersymmetric extension are discussed. We update various results by taking into account the new value of the top-quark mass obtained by the CDF Collaboration, and by including radiative corrections, some of which have been calculated only recently.

scholarly journals TOP QUARK PHYSICS AT THE TEVATRON

2013 ◽  
Vol 28 (08) ◽  
pp. 1330013 ◽  
Author(s):  
FRÉDÉRIC DÉLIOT ◽  
YVONNE PETERS ◽  
VERONICA SORIN
Keyword(s):  
Top Quark ◽  
Top Quarks ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Proton Antiproton ◽  
New Methods ◽  
Decay Properties ◽  
Large Program ◽  
The Standard Model ◽  
New Phenomena

The heaviest known elementary particle, the top quark, was discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton–antiproton collider at Fermilab. Since its discovery, a large program was set in motion by the CDF and D0 collaborations to characterize the production and decay properties of top quarks, and investigate their potential for searches of new phenomena beyond the standard model. During the past 20 years, new methods were developed and implemented to improve the measurements and searches for new physics in the top quark sector. This paper reviews the achievements and results obtained through studies of the top quark at the Tevatron.

THE "TOP PRIORITY" AT THE LHC

2008 ◽  
Vol 23 (25) ◽  
pp. 4107-4124 ◽  
Author(s):  
TAO HAN
Keyword(s):  
Elementary Particle ◽  
Top Quark ◽  
Hadron Collider ◽  
Top Quarks ◽  
New Physics ◽  
Great Accuracy ◽  
Electroweak Symmetry Breaking ◽  
Electroweak Symmetry ◽  
High Luminosity ◽  
The Standard Model

The LHC (Large Hadron Collider) will be a top-quark factory. With 80 million pairs of top quarks and an additional 34 million single tops produced annually at the designed high luminosity, the properties of this particle will be studied to a great accuracy. The fact that the top quark is the heaviest elementary particle in the Standard Model with a mass right at the electroweak scale makes it tempting to contemplate its role in electroweak symmetry breaking, as well as its potential as a window to unknown new physics at the TeV scale. We summarize the expectations for top-quark physics at the LHC, and outline new physics scenarios in which the top quark is crucially involved.

scholarly journals Probing Higgs boson CP properties with tt̄H at the LHC and the 100 TeV pp collider

2015 ◽  
Vol 30 (25) ◽  
pp. 1550156 ◽  
Author(s):  
Xiao-Gang He ◽  
Guan-Nan Li ◽  
Ya-Juan Zheng
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
New Physics ◽  
Final States ◽  
Discrimination Power ◽  
Text Production ◽  
Wide Range ◽  
The Standard Model ◽  
The Ideal

The Higgs boson [Formula: see text] has the largest coupling to the top quark [Formula: see text] among the standard model (SM) fermions. This is one of the ideal places to investigate new physics beyond SM. In this work, we study the potential of determining Higgs boson [Formula: see text] properties at the LHC and future 33 TeV and 100 TeV [Formula: see text] colliders by analyzing various operators formed from final states variables in [Formula: see text] production. The discrimination power from SM coupling is obtained with Higgs boson reconstructed from [Formula: see text] and [Formula: see text]. We find that [Formula: see text] process can provide more than [Formula: see text] discrimination power with [Formula: see text] integrated luminosity in a wide range of allowed Higgs to top couplings for the LHC, the 33 TeV and 100 TeV colliders. For [Formula: see text] the discrimination power will be below [Formula: see text] at the LHC, while for 33 TeV and 100 TeV colliders, more than [Formula: see text] sensitivity can be reached.

scholarly journals RECENT STUDIES OF TOP QUARK PROPERTIES AND DECAYS AT HADRON COLLIDERS

2012 ◽  
Vol 27 (33) ◽  
pp. 1230036 ◽  
Author(s):  
V. CHIOCHIA
Keyword(s):  
Elementary Particle ◽  
Standard Model ◽  
Top Quark ◽  
New Physics ◽  
Hadron Colliders ◽  
Statistical Precision ◽  
The Standard Model ◽  
Top Quark Production ◽  
Quark Production ◽  
First Time

The top quark is the heaviest known elementary particle. Observed for the first time in 1995 at the Tevatron by the CDF and D0 experiments, it has become object of several studies aimed to fully characterize its properties and decays. Precise determinations of top quark characteristics verify the internal consistency of the Standard Model (SM) and are sensitive to new physics phenomena. With the advent of the large top quark production rates generated at the LHC, top quark studies have reached unprecedented statistical precision. This review summarizes the recent measurements of top quark properties and studies of its decays performed at the LHC and Tevatron.

scholarly journals CONSTRAINING NEW MODELS WITH PRECISION ELECTROWEAK DATA

2006 ◽  
Vol 21 (19n20) ◽  
pp. 4045-4070 ◽  
Author(s):  
MU-CHUN CHEN ◽  
SALLY DAWSON ◽  
TADAS KRUPOVNICKAS
Keyword(s):  
Top Quark ◽  
New Physics ◽  
Tree Level ◽  
Symmetric Model ◽  
Top Quark Mass ◽  
Precision Data ◽  
The Standard Model ◽  
The One ◽  
Electroweak Precision ◽  
Electroweak Precision Data

Electroweak precision data have been extensively used to constrain models containing physics beyond that of the Standard Model (SM). When the model contains Higgs scalars in representations other than singlets or doublets, and hence ρ≠1 at tree-level, a correct renormalization scheme requires more inputs than the three commonly used for the SM case. In such cases, the one-loop electroweak results cannot be split into a SM contribution plus a piece which vanishes as the scale of new physics becomes much larger than MW. We illustrate our results by presenting the dependence of MW on the top-quark mass in a model with a Higgs triplet and in the SU (2)L × SU (2)R left–right symmetric model. In these models, the allowed range for the lightest neutral Higgs mass can be as large as a few TeV.

scholarly journals Top-philic heavy resonances in four-top final states and their EFT interpretation

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Luc Darmé ◽  
Benjamin Fuks ◽  
Fabio Maltoni
Keyword(s):  
Top Quark ◽  
Top Quarks ◽  
New Physics ◽  
Effective Field ◽  
Effective Theory ◽  
Final States ◽  
Large Transverse Momentum ◽  
Simplified Models ◽  
Quark Pairs ◽  
Heavy Resonances

Abstract With an expected rate of about one event per 100,000 top-quark pairs, four top-quark final states very rarely arise at the LHC. Though scarce, they offer a unique window onto top-quark compositeness, self-interactions and more generically, onto any top-philic new physics. By employing simplified models featuring heavy resonances, we study the range of validity of effective theory interpretations of current four top-quark analyses at the LHC and establish their future reach at the HL-LHC. We find that for the class of models under consideration, the effective field theory interpretations are not applicable. We therefore present the most up-to-date limits obtained from public CMS analyses using simplified models. Finally, we put forward a novel recasting strategy for the experimental results based on the production of top quarks with large transverse momentum.

THE STANDARD MODEL WITH THREE GENERATIONS: CLOSING IN ON THE TOP QUARK MASS

1989 ◽  
Vol 04 (04) ◽  
pp. 753-768 ◽  
Author(s):  
F. HALZEN ◽  
C. S. KIM ◽  
S. PAKVASA
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Top Quark ◽  
Quark Mass ◽  
New Physics ◽  
Experimental Information ◽  
Beyond The Standard Model ◽  
Top Quark Mass ◽  
Three Generations ◽  
The Standard Model

Within the standard model with three generations we fit the top quark mass mt by combining experimental information of [Formula: see text] and [Formula: see text] mixing, CP-violation in K decay and the ratio Γ(W)/Γ(Z) extracted from [Formula: see text] collider data. We conclude that [Formula: see text] where the "systematic error" associated with theoretical ambiguities in performing the calculations is likely to be significantly larger than the quoted 10 GeV error associated with input parameters and experimental data. The anticipated value essentially guarantees the discovery of the top quark by existing experiments. Failure to discover it should force us to reconsider generally accepted calculational procedures before it signals new physics beyond the standard model. We discuss this in some detail.

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