Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment

In the pp → tt ̄ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produce...

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Authors: Alconada Verzini, María Josefina; Alonso, Francisco; Arduh, Francisco Anuar; Dova, María Teresa; Monticelli, Fernando Gabriel; Wahlberg, Hernán Pablo; The ATLAS Collaboration
Format: Article
Status:Published version
Publication date:2016
Country:Argentina
Institution:UNLP
Repository:SEDICI (UNLP)
Language:English
OAI Identifier:oai:sedici.unlp.edu.ar:10915/77618
Online Access:http://sedici.unlp.edu.ar/handle/10915/77618
Access Level:Open access
Keyword:Ciencias Exactas
Física
charge asymmetry
highly boosted top-quark pair production
pp collision data
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author Alconada Verzini, María Josefina
author2 Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
author2_role author
author
author
author
author
author
author_browse Alconada Verzini, María Josefina
Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Monticelli, Fernando Gabriel
The ATLAS Collaboration
Wahlberg, Hernán Pablo
author_facet Alconada Verzini, María Josefina
Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
author_role author
collection SEDICI (UNLP)
description In the pp → tt ̄ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at √s = 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt ̄ > 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2 < |yt| − |yt ̄| < 2 is measured to be 4.2 ± 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt ̄ mass bins is also presented.
eu_rights_str_mv openAccess
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institution UNLP
instname_str Universidad Nacional de La Plata
language eng
network_acronym_str AR
network_name_str Argentina
oai_identifier_str oai:sedici.unlp.edu.ar:10915/77618
publishDate 2016
publishDateSort 2016
reponame_str SEDICI (UNLP)
spelling Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment Alconada Verzini, María Josefina Alonso, Francisco Arduh, Francisco Anuar Dova, María Teresa Monticelli, Fernando Gabriel Wahlberg, Hernán Pablo The ATLAS Collaboration Ciencias Exactas Física charge asymmetry highly boosted top-quark pair production pp collision data In the pp → tt ̄ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at √s = 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt ̄ > 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2 < |yt| − |yt ̄| < 2 is measured to be 4.2 ± 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt ̄ mass bins is also presented. Facultad de Ciencias Exactas http://sedici.unlp.edu.ar/handle/10915/77618
spellingShingle Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
Alconada Verzini, María Josefina
Ciencias Exactas
Física
charge asymmetry
highly boosted top-quark pair production
pp collision data
status_str publishedVersion
title Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
title_full Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
title_fullStr Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
title_full_unstemmed Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
title_short Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
title_sort Measurement of the charge asymmetry in highly boosted top-quark pair production in √s = 8 TeV pp collision data collected by the ATLAS experiment
topic Ciencias Exactas
Física
charge asymmetry
highly boosted top-quark pair production
pp collision data
topic_facet Ciencias Exactas
Física
charge asymmetry
highly boosted top-quark pair production
pp collision data
url http://sedici.unlp.edu.ar/handle/10915/77618