PROBING THE STANDARD MODEL WITH DILEPTON DECAYS OF TOP QUARK PAIRS AT CDF

2007 ◽  
Vol 22 (38) ◽  
pp. 2873-2884
Author(s):  
DANIEL WHITESON
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Top Quark ◽  
Production Cross Section ◽  
Production Cross ◽  
Fundamental Theory ◽  
Final State ◽  
Quark Pairs ◽  
The Standard Model ◽  
Selection Of

The dilepton decays of the top quark are a powerful laboratory for probing the Standard Model and searching for hints of a more fundamental theory. We present a detailed analysis of the production cross section and the kinematic qualities of top quark pair candidate events in [Formula: see text] collisions at [Formula: see text] = 1.96 TeV collected by the CDF detector which include two leptons in the final state, suggesting the decay [Formula: see text]. We describe the selection of candidate events to suppress major backgrounds and present the number of observed events over background. As a test of the top quark hypothesis, the kinematics of the events are analyzed via a measurement of M top with unprecedented precision.

ASSOCIATED PRODUCTION OF LIGHT PSEUDOSCALAR BOSON η WITH TOP QUARK PAIRS IN THE SLH MODEL AT THE ILC

2011 ◽  
Vol 26 (21) ◽  
pp. 1577-1586 ◽  
Author(s):  
JINZHONG HAN ◽  
DAPENG YANG ◽  
XUELEI WANG
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Linear Collider ◽  
International Linear Collider ◽  
Quark Pairs ◽  
Associated Production ◽  
The Standard Model ◽  
The Cross

The light pseudoscalar boson η is the typical particle predicted by the Simplest Little Higgs (SLH) model. In this paper, we investigate some processes of the associated production of a light pseudoscalar boson η with a pair of top quarks in the SLH model at the International Linear Collider (ILC), i.e. [Formula: see text] and [Formula: see text]. We find that the cross-sections of these two processes could reach [Formula: see text] fb in the favorite parameter space in the SLH model, which is consistent with the results of the cross-section of [Formula: see text] in the standard model and the cross-section of [Formula: see text] in the minimal supersymmetric standard model. It should be clear that hundreds to thousands of η can be produced at the ILC per year, these processes of [Formula: see text] are really interesting in testing the standard model and searching the signs of the SLH model.

MEASUREMENT OF THE W PAIR PRODUCTION CROSS SECTION AND W BRANCHING RATIOS WITH THE DELPHI DETECTOR

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 348-350
Author(s):  
FABIO COSSUTTI
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Ratios ◽  
Centre Of Mass ◽  
Delphi Detector ◽  
The Standard Model ◽  
Pair Production Cross Section

Data collected with the DELPHI detector at centre-of-mass energies up to the highest values explored by the LEP collider of about 206 GeV have been used to extract preliminary values of the cross-section for the process e+e- → W+W-. The branching ratios of the W decay were also measured; from them the value of |Vcs| was extracted. The results are compared with the most recent calculations in the framework of the Standard Model.

scholarly journals KK Higgs produced in association with a top quark pair in the bulk RS model

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
N. Manglani ◽  
A. Misra ◽  
K. Sridhar
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Cross Section ◽  
Top Quark ◽  
Production Cross Section ◽  
Search Strategy ◽  
Production Cross ◽  
Hadron Collider ◽  
Final State ◽  
Kaluza Klein

AbstractWe present a search strategy for the first Kaluza–Klein (KK) mode of the Higgs boson in the framework of the Randall–Sundrum (RS) model with a deformed metric. We study the production of this massive excitation in association with a $$ t {\bar{t}}$$tt¯ pair at the large hadron collider (LHC). The KK Higgs primarily decays into a boosted $$t {\bar{t}}$$tt¯ final state and we then end up with an interesting four-top final state of which two are boosted. The boosted products in the final state improve the sensitivity for the search of the KK Higgs in this channel whose production cross-section is otherwise rather small. Our results suggest that masses of the KK Higgs resonance upto about 1.2 TeV may be explorable at the highest planned luminosities of the LHC. Beyond this mass, the KK Higgs cross-section is too tiny for it to be explored at the LHC and may be possible only at a future higher energy collider.

scholarly journals PRELIMINARY MEASUREMENTS OF THE QUARK-ANTIQUARK PRODUCTION CROSS-SECTION IN E+E- ANNIHILATIONS UP TO LEP2 HIGHEST ENERGIES

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 342-344
Author(s):  
GIUSEPPE DELLA RICCA
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Delphi Detector ◽  
The Standard Model ◽  
Model Predictions ◽  
The Cross

Data collected with the DELPHI detector at [Formula: see text] up to LEP2 highest energies (i.e. exceeding 205 GeV) have been used to extract preliminary values of the cross-sections for quark-antiquark pair-production in e + e - annihilations. The values found were used to test the Standard Model predictions and to seek for physics beyond it.

scholarly journals Measurement of the inclusive and differential t$$ \overline{t} $$γ cross sections in the single-lepton channel and EFT interpretation at $$ \sqrt{s} $$ = 13 TeV

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Production Cross ◽  
Center Of Mass ◽  
Effective Field ◽  
Data Set ◽  
The Standard Model ◽  
Direct Limits

Abstract The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set, corresponding to an integrated luminosity of 137 fb−1, was recorded by the CMS experiment during the 2016–2018 data taking of the LHC. The measurements are performed in a fiducial volume defined at the particle level. Events with an isolated, highly energetic lepton, at least three jets from the hadronization of quarks, among which at least one is b tagged, and one isolated photon are selected. The inclusive fiducial t$$ \overline{\mathrm{t}} $$ t ¯ γ cross section, for a photon with transverse momentum greater than 20 GeV and pseudorapidity |η| < 1.4442, is measured to be 798 ± 7(stat) ± 48(syst) fb, in good agreement with the prediction from the standard model at next-to-leading order in quantum chromodynamics. The differential cross sections are also measured as a function of several kinematic observables and interpreted in the framework of the standard model effective field theory (EFT), leading to the most stringent direct limits to date on anomalous electromagnetic dipole moment interactions of the top quark and the photon.

scholarly journals CDF MULTI-MUON EVENTS AND SINGLET EXTENSIONS OF THE MSSM

2009 ◽  
Vol 24 (08) ◽  
pp. 557-566 ◽  
Author(s):  
FLORIAN DOMINGO ◽  
ULRICH ELLWANGER
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Supersymmetric Extension ◽  
Production Processes ◽  
The Standard Model ◽  
Additional Production ◽  
Large Production ◽  
Minimal Supersymmetric Extension

We discuss a generalization of the minimal supersymmetric extension of the Standard Model in the form of three additional singlet superfields, which would explain the essential features of the CDF multi-muon events presented recently: a large production cross section of ~ 100 pb originates from the production of a CP-odd scalar A with a mass in the 70–80 GeV range and a large value of tan β ~ 40. The CP-odd scalar A decays dominantly into CP-odd and CP-even scalars a1 and h1, which generate decay cascades h1 → 2h2 → 4a2 → 8τ, and a1 → h1 a2 with h1 decaying as above. The decay a2 → τ+τ- is slow, leading to a lifetime of [Formula: see text]. The phenomenology of the model differs from similar scenarios presented before in that one of the two cascades leads to 10 instead of 8 τ-leptons, and additional production processes like associate A production with [Formula: see text] pairs are relevant.

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