scholarly journals Intrinsic top quark properties - top mass, charge and polarisation

2013 ◽  
Author(s):  
Matteo Franchini
Keyword(s):  
Top Quark ◽  
Top Mass

QCD CORRECTION FACTORS FOR $K^0 -\overline K^0$ MIXING FOR LARGE TOP QUARK MASS

1990 ◽  
Vol 05 (11) ◽  
pp. 877-885 ◽  
Author(s):  
JONATHAN M. FLYNN
Keyword(s):  
Top Quark ◽  
Quark Mass ◽  
Correction Factors ◽  
Top Quark Mass ◽  
Factor B ◽  
Quark Masses ◽  
Effective Lagrangian ◽  
Mixing Parameter ◽  
200 Gev ◽  
Top Mass

I modify the calculation of the QCD correction factors in the ΔS = 2 effective Lagrangian for [Formula: see text] mixing to allow top quark masses in the range 50 GeV to 200 GeV. I give constraints on the top mass and Kobayashi-Maskawa phase, determined from the measured [Formula: see text] mixing parameter ε, and find that the factor BK and the ratio |Vub/Vcb| cannot both be smalI if mt < 200 GeV .

A VIEW OF THE TOP.

1998 ◽  
Vol 13 (17) ◽  
pp. 2883-2930 ◽  
Author(s):  
GIORGIO CHIARELLI
Keyword(s):  
Cross Section ◽  
Top Quark ◽  
Production Cross Section ◽  
Production Cross ◽  
Top Physics ◽  
Precision Measurements ◽  
Selection Strategies ◽  
Text Production ◽  
Top Mass

In this review I summarize the results obtained by CDF on top physics. After the discovery of the top quark, the efforts were concentrated on obtaining precision measurements of the observables. A description of the algorithms developed and used to isolate top in various samples is given, together with the discussion of background and selection strategies followed. The measurements of top mass and [Formula: see text] production cross section are discussed in detail and studies related to top decays and kinematics of [Formula: see text] events are presented.

scholarly journals IMPLICATIONS OF THE RECENT TOP QUARK DISCOVERY ON TWO-HIGGS DOUBLET MODEL

1995 ◽  
Vol 10 (12) ◽  
pp. 967-972 ◽  
Author(s):  
GYE T. PARK
Keyword(s):  
Top Quark ◽  
Branching Ratio ◽  
Higgs Doublet ◽  
Recent Measurement ◽  
Model Predictions ◽  
Charged Higgs ◽  
Doublet Model ◽  
Two Higgs Doublet Model ◽  
The Impact ◽  
Top Mass

Concentrating on the impact of the very recent top quark discovery, we perform a combined analysis of two strongest constraints on the two-Higgs doublet model, one coming from the recent measurement by CLEO on the inclusive branching ratio of b→sγ decay and the other from the recent LEP data on [Formula: see text] decay. We have included the model predictions for one-loop vertex corrections to [Formula: see text] through εb. We find that the εb constraint excludes most of the less appealing window: tan β≲1 at 95% C.L. for the measured top mass mt=176±8±10 GeV from CDF. Moreover, it excludes tan β≲2 at 95% C.L. for mt≳176 GeV; combined with the b→sγ constraint, only very heavy charged Higgs (≳670 GeV) is allowed by the measured mt from CDF.

QCD EFFECTS ON $B^0 -\bar{B}^0$ MIXINGS FOR VARIOUS VALUES OF THE TOP MASS

1988 ◽  
Vol 03 (15) ◽  
pp. 1479-1488 ◽  
Author(s):  
WILLIAM A. KAUFMAN ◽  
HERBERT STEGER ◽  
YORK-PENG YAO
Keyword(s):  
Lower Bound ◽  
Top Quark ◽  
W Bosons ◽  
The Masses ◽  
Top Mass

We consider QCD effects on [Formula: see text] systems when [Formula: see text] and [Formula: see text], where [Formula: see text] and mw are the masses of the top quark and the charged W bosons, respectively. They are markedly different from naïve extrapolations of formulae valid for [Formula: see text]. We then apply our results to the ARGUS [Formula: see text] mixing and obtain a lower bound [Formula: see text].

scholarly journals Two-loop anomalous dimensions of QCD operators up to dimension-sixteen and Higgs EFT amplitudes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Qing jun Jin ◽  
Ke Ren ◽  
Gang Yang
Keyword(s):  
Form Factor ◽  
Top Quark ◽  
Form Factors ◽  
Gluon Fusion ◽  
Effective Theory ◽  
Anomalous Dimensions ◽  
Minimal Form ◽  
Lorentz Scalar ◽  
Good Set ◽  
Top Mass

Abstract We consider two-loop renormalization of high-dimensional Lorentz scalar operators in the gluonic sector of QCD. These operators appear also in the Higgs effective theory obtained by integrating out the top quark loop in the gluon fusion process. We first discuss the classification of operators and how to construct a good set of basis using both off-shell field theory method and on-shell form factor formalism. To study loop corrections, we apply efficient unitarity-IBP strategy and compute the two-loop minimal form factors of length-3 operators up to dimension sixteen. From the UV divergences of form factor results, we extract the renormalization matrices and analyze the operator mixing behavior in detail. The form factors we compute are also equivalent to Higgs plus three-gluon amplitudes that capture high-order top mass corrections in Higgs EFT. We obtain the analytic finite remainder functions which exhibit several universal transcendentality structures.

scholarly journals TOP MASS MEASUREMENT AND BOTTOM FRAGMENTATION AT THE LHC

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 372-374 ◽  
Author(s):  
GENNARO CORCELLA
Keyword(s):  
Top Quark ◽  
Fragmentation Function ◽  
Quark Mass ◽  
Mass Measurement ◽  
Top Quark Mass ◽  
Quark Fragmentation ◽  
Top Mass ◽  
Mass Reconstruction

We show some recent HERWIG results related to the top quark mass reconstruction at the LHC and discuss possible improvements for studies of the bootom quark fragmentation function in the top decay.

scholarly journals What Is the Top Quark Mass?

2020 ◽  
Vol 70 (1) ◽  
pp. 225-255 ◽  
Author(s):  
André H. Hoang
Keyword(s):  
Monte Carlo ◽  
Top Quark ◽  
Quark Mass ◽  
Mass Parameter ◽  
Hadron Collider ◽  
Monte Carlo Event ◽  
Top Quark Mass ◽  
Mass Measurements ◽  
Top Mass ◽  
Interpretation Problem

This review provides an overview of the conceptual issues regarding the interpretation of so-called direct top quark mass measurements, which are based on the kinematic reconstruction of top quark decay products at the Large Hadron Collider (LHC). These measurements quote the top mass parameter [Formula: see text] of Monte Carlo event generators with current uncertainties of around 0.5 GeV. The problem of finding a rigorous relation between [Formula: see text] and top mass renormalization schemes defined in field theory is unresolved to date and touches perturbative as well as nonperturbative aspects and the limitations of state-of-the-art Monte Carlo event generators. I review the status of LHC top mass measurements, illustrate how conceptual limitations enter the picture, and explain a controversy that has permeated the community in the context of the interpretation problem related to [Formula: see text]. I then summarize recent advances in acquiring first principles insights and outline what else has to be understood to fully resolve the issue. I conclude with recommendations on how to deal with the interpretation problem for the time being when making top mass–dependent theoretical predictions.

scholarly journals DO PRESENT LEP DATA PROVIDE EVIDENCE FOR ELECTROWEAK CORRECTIONS?

1993 ◽  
Vol 08 (27) ◽  
pp. 2529-2538 ◽  
Author(s):  
V.A. NOVIKOV ◽  
L.B. OKUN ◽  
M.I. VYSOTSKY
Keyword(s):  
Top Quark ◽  
Precision Measurements ◽  
Positive Contribution ◽  
Virtual Particles ◽  
Electroweak Radiative Corrections ◽  
Upper Limits ◽  
Electroweak Precision ◽  
Lower Limits ◽  
Top Mass ◽  
Electroweak Corrections

The Born approximation, based on [Formula: see text] instead of α, reproduces all electroweak precision measurements within their (1σ) accuracy. The low upper limits for the genuinely electroweak corrections constitute one of the major achievements of LEP. The astonishing smallness of these corrections results from the cancellation of a large positive contribution from the heavy top quark and large negative contributions from all other virtual particles. It is precisely the non-observation of electroweak radiative corrections that places stringent upper and lower limits on the top mass.

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