scholarly journals Adversarially Learned Anomaly Detection on CMS open data: re-discovering the top quark

2021 ◽  
Vol 136 (2) ◽  
Author(s):  
O. Knapp ◽  
O. Cerri ◽  
G. Dissertori ◽  
T. Q. Nguyen ◽  
M. Pierini ◽  
...  
Keyword(s):  
Anomaly Detection ◽  
Top Quark ◽  
Hadron Collider ◽  
Real Life ◽  
Open Data ◽  
New Physics ◽  
Substantial Improvement ◽  
Proton Proton ◽  
8 Tev ◽  
Proton Proton Collisions

AbstractWe apply an Adversarially Learned Anomaly Detection (ALAD) algorithm to the problem of detecting new physics processes in proton–proton collisions at the Large Hadron Collider. Anomaly detection based on ALAD matches performances reached by Variational Autoencoders, with a substantial improvement in some cases. Training the ALAD algorithm on 4.4 fb$$^{-1}$$ - 1 of 8 TeV CMS Open Data, we show how a data-driven anomaly detection and characterization would work in real life, re-discovering the top quark by identifying the main features of the $$t \bar{t}$$ t t ¯ experimental signature at the LHC.

scholarly journals Search for s-channel single top-quark production in proton–proton collisions at s=8 TeV with the ATLAS detector

2015 ◽  
Vol 740 ◽  
pp. 118-136 ◽  
Author(s):  
G. Aad ◽  
B. Abbott ◽  
J. Abdallah ◽  
S. Abdel Khalek ◽  
O. Abdinov ◽  
...  
Keyword(s):  
Top Quark ◽  
Atlas Detector ◽  
Proton Proton ◽  
Proton Collisions ◽  
Single Top ◽  
Top Quark Production ◽  
Quark Production ◽  
8 Tev ◽  
Proton Proton Collisions

scholarly journals Measurement of top quark properties at the Tevatron and LHC

2014 ◽  
Vol 31 ◽  
pp. 1460278
Author(s):  
Fabrizio Margaroli ◽  
Keyword(s):  
Coming Out ◽  
Top Quark ◽  
Top Quarks ◽  
Proton Proton ◽  
New Era ◽  
Proton Collisions ◽  
The Standard Model ◽  
8 Tev ◽  
Proton Proton Collisions ◽  
Selection Of

Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ago, yet some interesting results are coming out of the CDF and D0 collaborations. The LHC collider at CERN produced two orders of magnitude more top quarks than Tevatron's, thus giving birth to a new era for top quark physics. While the LHC is also down at the time of this writing, many top quark physics results are being extracted out of the 7 TeV and 8 TeV proton proton collisions by the ATLAS and CMS collaborations, and many more are expected to appear before the LHC will be turned on again sometime in 2015. These proceedings cover a selection of recent results produced by the Tevatron and LHC experiments.

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 Search for pair production of scalar leptoquarks decaying into first- or second-generation leptons and top quarks in proton–proton collisions at $$\sqrt{s}$$ = 13 TeV with the ATLAS detector

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Pair Production ◽  
Top Quark ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Large Radius ◽  
Proton Proton ◽  
Proton Collisions ◽  
Muon Channel ◽  
Scalar Leptoquarks ◽  
Proton Proton Collisions

AbstractA search for pair production of scalar leptoquarks, each decaying into either an electron or a muon and a top quark, is presented. This is the first leptoquark search using ATLAS data to investigate top-philic cross-generational couplings that could provide explanations for recently observed anomalies in B meson decays. This analysis targets high leptoquark masses which cause the decay products of each resultant top quark to be contained within a single high-$$p_{\mathrm {T}}$$ p T large-radius jet. The full Run 2 dataset is exploited, consisting of $$139~\hbox {fb}^{-1}$$ 139 fb - 1 of data collected from proton–proton collisions at $$\sqrt{s}=13~\mathrm {TeV}$$ s = 13 TeV from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. In the absence of any significant deviation from the background expectation, lower limits on the leptoquark masses are set at $$1480~\mathrm {GeV}$$ 1480 GeV and $$1470~\mathrm {GeV}$$ 1470 GeV for the electron and muon channel, respectively.

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