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Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector

Publication ,  Journal Article
Aad, G; Abbott, B; Abdallah, J; Abdel Khalek, S; Abdinov, O; Aben, R; Abi, B; Abolins, M; Abouzeid, OS; Abramowicz, H; Abreu, H; Abreu, R ...
Published in: Physical Review D - Particles, Fields, Gravitation and Cosmology
April 28, 2015
Published version (DOI)

A search is performed for top-quark pairs (tt¯) produced together with a photon (γ) with transverse energy greater than 20 GeV using a sample of tt¯ candidate events in final states with jets, missing transverse momentum, and one isolated electron or muon. The data set used corresponds to an integrated luminosity of 4.59 fb-1 of proton-proton collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. In total, 140 and 222 tt¯γ candidate events are observed in the electron and muon channels, to be compared to the expectation of 79±26 and 120±39 non-tt¯γ background events, respectively. The production of tt¯γ events is observed with a significance of 5.3 standard deviations away from the null hypothesis. The tt¯γ production cross section times the branching ratio (BR) of the single-lepton decay channel is measured in a fiducial kinematic region within the ATLAS acceptance. The measured value is σtt¯γfid×BR=63±8(stat)-13+17(syst)±1(lumi) fb per lepton flavor, in good agreement with the leading-order theoretical calculation normalized to the next-to-leading-order theoretical prediction of 48±10 fb.

Duke Scholars

Ayana T. Arce
Author Ayana T. Arce Physics
Alfred T. Goshaw
Author Alfred T. Goshaw Physics
Ashutosh V. Kotwal
Author Ashutosh V. Kotwal Physics
Mark C. Kruse
Author Mark C. Kruse Physics
Seog Oh
Author Seog Oh Physics
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Published In

Physical Review D - Particles, Fields, Gravitation and Cosmology

DOI

10.1103/PhysRevD.91.072007

EISSN

1550-2368

ISSN

1550-7998

Publication Date

April 28, 2015

Volume

91

Issue

7

Related Subject Headings

  • Nuclear & Particles Physics
  • 5107 Particle and high energy physics
  • 5101 Astronomical sciences
  • 4902 Mathematical physics
  • 0206 Quantum Physics
  • 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
  • 0201 Astronomical and Space Sciences
 

Citation

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MLA
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Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., Aben, R., … Arnal, V. (2015). Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector. Physical Review D - Particles, Fields, Gravitation and Cosmology, 91(7). https://doi.org/10.1103/PhysRevD.91.072007
Aad, G., B. Abbott, J. Abdallah, S. Abdel Khalek, O. Abdinov, R. Aben, B. Abi, et al. “Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector.” Physical Review D - Particles, Fields, Gravitation and Cosmology 91, no. 7 (April 28, 2015). https://doi.org/10.1103/PhysRevD.91.072007.
Aad G, Abbott B, Abdallah J, Abdel Khalek S, Abdinov O, Aben R, et al. Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2015 Apr 28;91(7).
Aad, G., et al. “Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector.” Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 91, no. 7, Apr. 2015. Scopus, doi:10.1103/PhysRevD.91.072007.
Aad G, Abbott B, Abdallah J, Abdel Khalek S, Abdinov O, Aben R, Abi B, Abolins M, Abouzeid OS, Abramowicz H, Abreu H, Abreu R, Abulaiti Y, Acharya BS, Adamczyk L, Adams DL, Adelman J, Adomeit S, Adye T, Agatonovic-Jovin T, Aguilar-Saavedra JA, Agustoni M, Ahlen SP, Ahmadov F, Aielli G, Akerstedt H, Åkesson TPA, Akimoto G, Akimov AV, Alberghi GL, Albert J, Albrand S, Alconada Verzini MJ, Aleksa M, Aleksandrov IN, Alexa C, Alexander G, Alexandre G, Alexopoulos T, Alhroob M, Alimonti G, Alio L, Alison J, Allbrooke BMM, Allison LJ, Allport PP, Almond J, Aloisio A, Alonso A, Alonso F, Alpigiani C, Altheimer A, Alvarez Gonzalez B, Alviggi MG, Amako K, Amaral Coutinho Y, Amelung C, Amidei D, Amor Dos Santos SP, Amorim A, Amoroso S, Amram N, Amundsen G, Anastopoulos C, Ancu LS, Andari N, Andeen T, Anders CF, Anders G, Anderson KJ, Andreazza A, Andrei V, Anduaga XS, Angelidakis S, Angelozzi I, Anger P, Angerami A, Anghinolfi F, Anisenkov AV, Anjos N, Annovi A, Antonaki A, Antonelli M, Antonov A, Antos J, Anulli F, Aoki M, Aperio Bella L, Apolle R, Arabidze G, Aracena I, Arai Y, Araque JP, Arce ATH, Arguin JF, Argyropoulos S, Arik M, Armbruster AJ, Arnaez O, Arnal V. Observation of top-quark pair production in association with a photon and measurement of the t t ¯ γ production cross section in pp collisions at √s =7 TeV using the ATLAS detector. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2015 Apr 28;91(7).

Published In

Physical Review D - Particles, Fields, Gravitation and Cosmology

DOI

10.1103/PhysRevD.91.072007

EISSN

1550-2368

ISSN

1550-7998

Publication Date

April 28, 2015

Volume

91

Issue

7

Related Subject Headings

  • Nuclear & Particles Physics
  • 5107 Particle and high energy physics
  • 5101 Astronomical sciences
  • 4902 Mathematical physics
  • 0206 Quantum Physics
  • 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
  • 0201 Astronomical and Space Sciences