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

Atlas Collaboration

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Abstract

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=8TeV 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|−|y|<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.

Original languageEnglish
Pages (from-to)52-71
Number of pages20
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume756
DOIs
Publication statusPublished - May 10 2016

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pair production
asymmetry
quarks
collisions
angular distribution
topology
decay
predictions

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics

Cite this

@article{d89f3d33abfa46f79a14e2da7af51c63,
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",
abstract = "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=8TeV 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.",
author = "{Atlas Collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and B. Abeloos and R. Aben and M. Abolins and AbouZeid, {O. S.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and J. Adelman and S. Adomeit and T. Adye and Affolder, {A. A.} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, {J. A.} and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P.A.} and Akimov, {A. V.} and Alberghi, {G. L.} and J. Albert and S. Albrand and {Alconada Verzini}, {M. J.} and M. Aleksa and Aleksandrov, {I. N.} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and J. Alison and Alkire, {S. P.} and Allbrooke, {B. M.M.} and Allen, {B. W.} and Allport, {P. P.} and A. Aloisio and A. Alonso and F. Alonso and C. Alpigiani and {Alvarez Gonzalez}, B. and {{\'A}lvarez Piqueras}, D.",
year = "2016",
month = "5",
day = "10",
doi = "10.1016/j.physletb.2016.02.055",
language = "English",
volume = "756",
pages = "52--71",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",

}

TY - JOUR

T1 - Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment

AU - Atlas Collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdinov, O.

AU - Abeloos, B.

AU - Aben, R.

AU - Abolins, M.

AU - AbouZeid, O. S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abreu, R.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Adamczyk, L.

AU - Adams, D. L.

AU - Adelman, J.

AU - Adomeit, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Agatonovic-Jovin, T.

AU - Agricola, J.

AU - Aguilar-Saavedra, J. A.

AU - Ahlen, S. P.

AU - Ahmadov, F.

AU - Aielli, G.

AU - Akerstedt, H.

AU - Åkesson, T. P.A.

AU - Akimov, A. V.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albrand, S.

AU - Alconada Verzini, M. J.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alexa, C.

AU - Alexander, G.

AU - Alexopoulos, T.

AU - Alhroob, M.

AU - Alimonti, G.

AU - Alison, J.

AU - Alkire, S. P.

AU - Allbrooke, B. M.M.

AU - Allen, B. W.

AU - Allport, P. P.

AU - Aloisio, A.

AU - Alonso, A.

AU - Alonso, F.

AU - Alpigiani, C.

AU - Alvarez Gonzalez, B.

AU - Álvarez Piqueras, D.

PY - 2016/5/10

Y1 - 2016/5/10

N2 - 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=8TeV 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.

AB - 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=8TeV 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.

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U2 - 10.1016/j.physletb.2016.02.055

DO - 10.1016/j.physletb.2016.02.055

M3 - Article

AN - SCOPUS:85042466567

VL - 756

SP - 52

EP - 71

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

SN - 0370-2693

ER -