scholarly journals Transverse polarization of top quarks produced at a photon-photon collider

1995 ◽  
Vol 51 (5) ◽  
pp. 2475-2477 ◽  
Author(s):  
W. Bernreuther ◽  
J. P. Ma ◽  
B. H. J. McKellar
Keyword(s):  
Top Quarks ◽  
Transverse Polarization ◽  
Photon Collider

DETECTION OF TOP QUARKS IN A PHOTON–PHOTON COLLIDER

2000 ◽  
Vol 15 (16) ◽  
pp. 2599-2604
Author(s):  
TOHRU TAKAHASHI ◽  
KATSUMASA IKEMATSU
Keyword(s):  
Top Quark ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Top Quarks ◽  
Signal To Noise ◽  
Quark Pairs ◽  
Photon Collider ◽  
Noise Ratio ◽  
Top Quark Pairs

We report the feasibility of detection of top quark pairs in a photon–photon collider. A realistic luminosity and detection efficiency were estimated using a simulation with a set of accelerator and detector parameters. It was found that about 1000 events can be expected with the signal to noise ratio of 10 in a year of operation.

scholarly journals ZH production in gluon fusion: two-loop amplitudes with full top quark mass dependence

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Long Chen ◽  
Gudrun Heinrich ◽  
Stephen P. Jones ◽  
Matthias Kerner ◽  
Jonas Klappert ◽  
...  
Keyword(s):  
Top Quark ◽  
Quark Mass ◽  
Gluon Fusion ◽  
Top Quarks ◽  
Mass Dependence ◽  
Finite Part ◽  
Top Quark Mass ◽  
Helicity Amplitudes ◽  
Quark Mass Dependence ◽  
Loop Amplitudes

Abstract We present results for the two-loop helicity amplitudes entering the NLO QCD corrections to the production of a Higgs boson in association with a Z -boson in gluon fusion. The two-loop integrals, involving massive top quarks, are calculated numerically. Results for the interference of the finite part of the two-loop amplitudes with the Born amplitude are shown as a function of the two kinematic invariants on which the amplitudes depend.

scholarly journals Anomaly detection with convolutional Graph Neural Networks

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Oliver Atkinson ◽  
Akanksha Bhardwaj ◽  
Christoph Englert ◽  
Vishal S. Ngairangbam ◽  
Michael Spannowsky
Keyword(s):  
Neural Networks ◽  
Anomaly Detection ◽  
Top Quarks ◽  
New Physics ◽  
Broad Applicability ◽  
Latent Space ◽  
Edge Features ◽  
Graph Neural Networks ◽  
Promising Avenue ◽  
Do So

Abstract We devise an autoencoder based strategy to facilitate anomaly detection for boosted jets, employing Graph Neural Networks (GNNs) to do so. To overcome known limitations of GNN autoencoders, we design a symmetric decoder capable of simultaneously reconstructing edge features and node features. Focusing on latent space based discriminators, we find that such setups provide a promising avenue to isolate new physics and competing SM signatures from sensitivity-limiting QCD jet contributions. We demonstrate the flexibility and broad applicability of this approach using examples of W bosons, top quarks, and exotic hadronically-decaying exotic scalar bosons.

scholarly journals Search for $$ t\overline{t} $$ resonances in fully hadronic final states in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Production Cross ◽  
Hadron Collider ◽  
Top Quarks ◽  
Atlas Detector ◽  
Proton Collision ◽  
Large Radius ◽  
Final States ◽  
Jet Substructure ◽  
High Transverse Momentum ◽  
Hadronic Final States

Abstract This paper presents a search for new heavy particles decaying into a pair of top quarks using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search is performed using events consistent with pair production of high-transverse-momentum top quarks and their subsequent decays into the fully hadronic final states. The analysis is optimized for resonances decaying into a $$ t\overline{t} $$ t t ¯ pair with mass above 1.4 TeV, exploiting a dedicated multivariate technique with jet substructure to identify hadronically decaying top quarks using large-radius jets and evaluating the background expectation from data. No significant deviation from the background prediction is observed. Limits are set on the production cross-section times branching fraction for the new Z′ boson in a topcolor-assisted-technicolor model. The Z′ boson masses below 3.9 and 4.7 TeV are excluded at 95% confidence level for the decay widths of 1% and 3%, respectively.

scholarly journals Supersymmetric prediction for the muon transverse polarization in theK+→π0μ+νμdecay

1997 ◽  
Vol 55 (9) ◽  
pp. 5334-5340 ◽  
Author(s):  
Marco Fabbrichesi ◽  
Francesco Vissani
Keyword(s):  
Transverse Polarization
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