scholarly journals PROBING NEW PHYSICS FROM TOP QUARK FCNC PROCESS AT LHC: A MINI REVIEW

2008 ◽  
Vol 23 (21) ◽  
pp. 3343-3347 ◽  
Author(s):  
JIN MIN YANG
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
New Physics ◽  
Supersymmetric Model ◽  
The Standard Model ◽  
Minimal Supersymmetric Model

Since the top quark FCNC processes are extremely supressed in the Standard Model (SM) but could be greatly enhanced in some new physics models, they could serve as a smoking gun for new physics hunting at the LHC. In this brief review we summarize the new physics predictions for various top quark FCNC processes at the LHC by focusing on two typical models: the minimal supersymmetric model (MSSM) and the topcolor-assisted technicolor (TC2) model. The conclusion is: (1) Both new physics models can greatly enhance the SM predictions by several orders; (2) The TC2 model allows for largest enhancement, and for each channel the maximal prediction is much larger than in the MSSM; (3) Compared with the 3σ sensitivity at the LHC, only a couple of channels are accessible for the MSSM while most channles are accesible for the TC2 model.

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 searches beyond the Standard Model

2014 ◽  
Vol 31 ◽  
pp. 1460288 ◽  
Author(s):  
R. Mankel ◽  
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
Beyond The Standard Model ◽  
Model Interpretation ◽  
The Standard Model ◽  
Extended Higgs Sectors ◽  
Minimal Supersymmetric Model

While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Besides the Standard Model interpretation, various possibilities for extended Higgs sectors are being considered. The minimal supersymmetric extension (MSSM) features two Higgs doublets resulting in five physical Higgs bosons, which are subject to direct searches. Alternatively, more generic Two-Higgs Doublet models (2HDM) are used for the interpretation of results. The Next-to-Minimal Supersymmetric Model (NMSSM) has a more complex Higgs sector with seven physical states. Also exotic Higgs bosons decaying to invisible final states are considered. This article summarizes recent findings based on results from collider experiments.

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.

HIGGS BOSONS

1990 ◽  
Vol 05 (26) ◽  
pp. 2087-2100 ◽  
Author(s):  
A. MÉNDEZ
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
The Standard Model ◽  
Doublet Model ◽  
Minimal Supersymmetric Model ◽  
Extended Higgs Sector

The main phenomenological aspects of the Higgs bosons are briefly reviewed in the context of the Standard Model and in models with an "extended" Higgs sector. Among the latter, special emphasis is made on the Two-Doublet Model and, particularly, the Minimal Supersymmetric Model.

scholarly journals Exact one-loop running couplings in the standard model

2008 ◽  
Vol 86 (9) ◽  
pp. 1067-1070 ◽  
Author(s):  
F A Chishtie ◽  
M D Lepage ◽  
D GC McKeon ◽  
T G Steele ◽  
I Zakout
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
Top Quark ◽  
Higgs Mass ◽  
Gauge Coupling ◽  
New Physics ◽  
Energy Scale ◽  
Scalar Coupling ◽  
Upper And Lower Bounds ◽  
The Standard Model

Taking the dominant couplings in the standard model to be the quartic scalar coupling, the Yukawa coupling of the top quark, and the SU(3) gauge coupling, we consider their associated running couplings to one-loop order. Despite the nonlinear nature of the differential equations governing these functions, we show that they can be solved exactly. The nature of these solutions is discussed and their singularity structure is examined. It is shown that for a sufficiently small Higgs mass, the quartic scalar coupling decreases with increasing energy scale and becomes negative, indicative of vacuum instability. This behavior changes for a Higgs mass greater than 168 GeV, beyond which this couplant increases with increasing energy scales and becomes singular prior to the ultraviolet pole of the Yukawa coupling. Upper and lower bounds on the Higgs mass corresponding to new physics at the TeV scale are obtained and compare favourably with the numerical results of the one-loop and two-loop analyses with inclusion of electroweak couplings.PACS Nos.: 11.10.Hi, 14.80.Bn

scholarly journals Higgs searches beyond the Standard Model

2014 ◽  
Vol 29 (24) ◽  
pp. 1430057
Author(s):  
R. Mankel ◽  
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Higgs Bosons ◽  
Supersymmetric Model ◽  
Beyond The Standard Model ◽  
Model Interpretation ◽  
The Standard Model ◽  
Extended Higgs Sectors ◽  
Minimal Supersymmetric Model

While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Besides the Standard Model interpretation, various possibilities for extended Higgs sectors are being considered. The minimal supersymmetric extension (MSSM) features two Higgs doublets resulting in five physical Higgs bosons, which are subject to direct searches. Alternatively, more generic Two-Higgs Doublet models (2HDM) are used for the interpretation of results. The Next-to-Minimal Supersymmetric Model (NMSSM) has a more complex Higgs sector with seven physical states. Also exotic Higgs bosons decaying to invisible final states are considered. This article summarizes recent findings based on results from collider experiments.

scholarly journals SEARCHES FOR NEW PARTICLES

2002 ◽  
Vol 17 (23) ◽  
pp. 3336-3351 ◽  
Author(s):  
GAIL G. HANSON
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
New Physics ◽  
Higgs Bosons ◽  
Standard Model Higgs Boson ◽  
The Past ◽  
Flavor Changing ◽  
The Standard Model ◽  
The Status ◽  
New Particles

The status of searches for new particles and new physics during the past year at the Fermilab Tevatron, at HERA and at LEP is summarized. A discussion of the hints for the Standard Model Higgs boson from LEP2 data is presented. Searches for non-Standard Model Higgs bosons are also described. Many searches have been carried out for the particles predicted by supersymmetry theories, and a sampling of these is given. There have also been searches for flavor changing neutral currents in the interactions of the top quark. In addition, searches for excited leptons, leptoquarks and technicolor are summarized.

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 DIRECT CP VIOLATION AND NEW PHYSICS EFFECTS IN THE DECAY MODE B+→ϕK+

2004 ◽  
Vol 19 (25) ◽  
pp. 1903-1918 ◽  
Author(s):  
ANJAN K. GIRI ◽  
RUKMANI MOHANTA
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Decay Mode ◽  
Percent Level ◽  
New Physics ◽  
Supersymmetric Model ◽  
Beyond The Standard Model ◽  
Cp Asymmetry ◽  
Penguin Diagram ◽  
The Standard Model

We study the direct CP violation effect in the decay mode B+→ϕK+. This decay mode is dominated by the loop induced [Formula: see text] penguin diagram with a tiny contribution from the annihilation diagram. Therefore, the standard model expectation of direct CP violation is negligibly small. Using QCD factorization approach we find the CP asymmetry in the standard model to be at percent level. We consider then two scenarios beyond the standard model, the model with an extra vector-like down quark (VLDQ) and the R-parity violating supersymmetric model (RPV) and show that the direct CP violating asymmetry in B+→ϕK+ could be as large as ~ 85% (70%) in VLDQ (RPV) model.

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