scholarly journals Polarized top quarks from new physics: Signals and observables

2009 ◽  
Vol 79 (1) ◽  
Author(s):  
Jessie Shelton
Keyword(s):  
Top Quarks ◽  
New Physics

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 TOP QUARK PHYSICS AT THE TEVATRON

2013 ◽  
Vol 28 (08) ◽  
pp. 1330013 ◽  
Author(s):  
FRÉDÉRIC DÉLIOT ◽  
YVONNE PETERS ◽  
VERONICA SORIN
Keyword(s):  
Top Quark ◽  
Top Quarks ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Proton Antiproton ◽  
New Methods ◽  
Decay Properties ◽  
Large Program ◽  
The Standard Model ◽  
New Phenomena

The heaviest known elementary particle, the top quark, was discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton–antiproton collider at Fermilab. Since its discovery, a large program was set in motion by the CDF and D0 collaborations to characterize the production and decay properties of top quarks, and investigate their potential for searches of new phenomena beyond the standard model. During the past 20 years, new methods were developed and implemented to improve the measurements and searches for new physics in the top quark sector. This paper reviews the achievements and results obtained through studies of the top quark at the Tevatron.

THE "TOP PRIORITY" AT THE LHC

2008 ◽  
Vol 23 (25) ◽  
pp. 4107-4124 ◽  
Author(s):  
TAO HAN
Keyword(s):  
Elementary Particle ◽  
Top Quark ◽  
Hadron Collider ◽  
Top Quarks ◽  
New Physics ◽  
Great Accuracy ◽  
Electroweak Symmetry Breaking ◽  
Electroweak Symmetry ◽  
High Luminosity ◽  
The Standard Model

The LHC (Large Hadron Collider) will be a top-quark factory. With 80 million pairs of top quarks and an additional 34 million single tops produced annually at the designed high luminosity, the properties of this particle will be studied to a great accuracy. The fact that the top quark is the heaviest elementary particle in the Standard Model with a mass right at the electroweak scale makes it tempting to contemplate its role in electroweak symmetry breaking, as well as its potential as a window to unknown new physics at the TeV scale. We summarize the expectations for top-quark physics at the LHC, and outline new physics scenarios in which the top quark is crucially involved.

scholarly journals Observability of Production of tttt quarks at pp-colliders in new physics models

2020 ◽  
Vol 18 ◽  
pp. 66-77
Author(s):  
Abdeljali Habjial
Keyword(s):  
Standard Model ◽  
Production Process ◽  
Background Noise ◽  
Center Of Mass ◽  
Top Quarks ◽  
New Physics ◽  
Atlas Detector ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
The Standard Model

The Standard Model production of four top quarks in the process pp --> tttt at a center-of-mass energy s1/2=13 Tev. The data collected by the ATLAS detector represents an impressive study potential, with an integrated luminosity of around 139 fb-1. In this manuscript, we present the production process of four top quarks at the LHC as well as some new physics models associated with this process. These models are studied in analysis carried. Some preliminary results are presented, in particular those of a new method for estimating background noise due to false leptons developed.

scholarly journals Top quarks as a probe for heavy new physics

2014 ◽  
Author(s):  
Celine Catherine Degrande
Keyword(s):  
Top Quarks ◽  
New Physics

scholarly journals Search for new physics in top quark production with additional leptons in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV using effective field theory

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Top Quark ◽  
Center Of Mass ◽  
Top Quarks ◽  
New Physics ◽  
Effective Field ◽  
Proton Proton ◽  
Proton Collisions ◽  
Proton Proton Collisions

Abstract Events containing one or more top quarks produced with additional prompt leptons are used to search for new physics within the framework of an effective field theory (EFT). The data correspond to an integrated luminosity of 41.5 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC, collected by the CMS experiment in 2017. The selected events are required to have either two leptons with the same charge or more than two leptons; jets, including identified bottom quark jets, are also required, and the selected events are divided into categories based on the multiplicities of these objects. Sixteen dimension-six operators that can affect processes involving top quarks produced with additional charged leptons are considered in this analysis. Constructed to target EFT effects directly, the analysis applies a novel approach in which the observed yields are parameterized in terms of the Wilson coefficients (WCs) of the EFT operators. A simultaneous fit of the 16 WCs to the data is performed and two standard deviation confidence intervals for the WCs are extracted; the standard model expectations for the WC values are within these intervals for all of the WCs probed.

scholarly journals Top-philic heavy resonances in four-top final states and their EFT interpretation

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Luc Darmé ◽  
Benjamin Fuks ◽  
Fabio Maltoni
Keyword(s):  
Top Quark ◽  
Top Quarks ◽  
New Physics ◽  
Effective Field ◽  
Effective Theory ◽  
Final States ◽  
Large Transverse Momentum ◽  
Simplified Models ◽  
Quark Pairs ◽  
Heavy Resonances

Abstract With an expected rate of about one event per 100,000 top-quark pairs, four top-quark final states very rarely arise at the LHC. Though scarce, they offer a unique window onto top-quark compositeness, self-interactions and more generically, onto any top-philic new physics. By employing simplified models featuring heavy resonances, we study the range of validity of effective theory interpretations of current four top-quark analyses at the LHC and establish their future reach at the HL-LHC. We find that for the class of models under consideration, the effective field theory interpretations are not applicable. We therefore present the most up-to-date limits obtained from public CMS analyses using simplified models. Finally, we put forward a novel recasting strategy for the experimental results based on the production of top quarks with large transverse momentum.

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