scholarly journals A set of top quark spin correlation and polarization observables for the LHC: Standard Model predictions and new physics contributions

2015 ◽  
Vol 2015 (12) ◽  
pp. 1-36 ◽  
Author(s):  
Werner Bernreuther ◽  
Dennis Heisler ◽  
Zong-Guo Si
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Spin Correlation ◽  
New Physics ◽  
Quark Spin ◽  
Model Predictions ◽  
Polarization Observables

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.

CP VIOLATION IN THE B SYSTEM—A STATISTICAL ANALYSIS

1990 ◽  
Vol 05 (05) ◽  
pp. 337-347
Author(s):  
DAVID LONDON
Keyword(s):  
Statistical Analysis ◽  
Cp Violation ◽  
Standard Model ◽  
Probability Distributions ◽  
New Physics ◽  
Hadronic Decay ◽  
System A ◽  
The Standard Model ◽  
Model Predictions ◽  
Cp Asymmetries

The standard model predictions for CP violating hadronic decay asymmetries are presented in the form of probability distributions. From these distributions, it can be easily seen what the most likely values of these quantities are, which measurements would clearly be signs of new physics, and which values of the CP asymmetries would most constrain the parameters of the standard model.

CHARM MIXING AND CP VIOLATION AT B-FACTORIES

2014 ◽  
Vol 35 ◽  
pp. 1460413
Author(s):  
GIANLUIGI CIBINETTO ◽  
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
New Physics ◽  
Ratio Analysis ◽  
Charm Meson ◽  
Final State ◽  
Charm Decays ◽  
Decay Modes ◽  
The Standard Model ◽  
Model Predictions

CP violation in charm decays is expected to be very small in the Standard Model, at the level of 0.1% or less. A sizable excess of CP violation with respect to the Standard Model predictions could be a signature of new physics. We report on recent searches for CP violation in charm meson decays at BABAR and Belle experiments. In particular we report a lifetime ratio analysis of D0 → K+K−, π+π− with respect to D0 → K−π+ decays, which is sensitive to [Formula: see text] mixing and CP violation. We report also on searches for CPV in the 3-body D+ → K+K−π+ decay and for decay modes with a [Formula: see text] in the final state, such as [Formula: see text].

scholarly journals η′K PUZZLE OF B MESON DECAYS AND NEW PHYSICS EFFECTS IN THE TC2 MODEL

2001 ◽  
Vol 16 (07) ◽  
pp. 441-455 ◽  
Author(s):  
ZHENJUN XIAO ◽  
WENJUN LI ◽  
GONGRU LU ◽  
LIBO GUO
Keyword(s):  
Standard Model ◽  
B Meson ◽  
New Physics ◽  
Decay Rates ◽  
Low Energy ◽  
Effective Hamiltonian ◽  
B Meson Decays ◽  
The Standard Model ◽  
Model Predictions ◽  
Input Parameters

Using the low energy effective Hamiltonian with the generalized factorization, we calculate the new physics contributions to B→π+π-, Kπ and Kη′ in the topcolor-assisted-technicolor (TC2) model, and compare the results with the available data. By using [Formula: see text] preferred by the CLEO data of B→π+π-decay, we find that the new physics enhancements to B→ Kη′ decays are significant in size, ~ 50% with respect to the standard model predictions, insensitive to the variations of input parameters and hence provide a simple and plausible new physics interpretation for the observed unexpectedly large B→ Kη′ decay rates.

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.

Μελέτη των διασπάσεων αλλαγής γεύσης ουδετέρου ρεύματος του top κουάρκ στα πλαίσια του πειράματος CMS/LHC

2007 ◽  
Author(s):  
Γρηγόριος Βερμίσογλου
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Z Boson ◽  
New Physics ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
Leptonic Decays ◽  
Quark Sector ◽  
Systematic Effects ◽  
Detector Simulation

This study contains the first realistic estimate for the CMS/LHC sensitivity to Flavour Changing Neutral Currents (FCNC) in the top quark sector. The non-Standard Model decays t→Zq and t→ γ q (where q = u, c) have been studied at √s = 14 TeV exploiting the leptonic decays of the Z⁰ boson and the photon. A realistic detector simulation has been used and the most important systematic effects have been addressed. The 5-sigma discovery limits for the two decays are BR(t→qZ)= 11.4 x 10⁻⁴ and BR(t→ γ q)= 5.7 x 10⁻⁴, allowing some models of new physics to be tested.

Top quark polarization and -odd spin correlations as tools for testing (non) standard model predictions

1992 ◽  
Vol 297 (3-4) ◽  
pp. 318-326 ◽  
Author(s):  
W. Bernreuther ◽  
J.P. Ma ◽  
T. Schröder
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Spin Correlations ◽  
Model Predictions

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.

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