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

G. Aad; B. Abbott; J. Abdallah; O. Abdinov; B. Abellos; R. Aben; M. Abolins; O.S. AbouZeid; H. Abramowicz; H. Abreu; Mogens Dam; Jørn Dines Hansen; Jørgen Beck Hansen; Stefania Xella; Peter Henrik Hansen; Troels Christian Petersen; Lotte Ansgaard Thomsen; Sascha Mehlhase; Almut Maria Pingel; Alejandro Alonso Diaz; James William Monk; Gorm Aske Gram Krohn Galster; Lotte Ansgaard Thomsen; Ask Emil Løvschall-Jensen; Graig Wiglesworth; Lars Egholm Pedersen; Simon Holm Stark

doi:10.1016/j.physletb.2016.02.055

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

G. Aad, B. Abbott, J. Abdallah, O. Abdinov, B. Abellos, R. Aben, M. Abolins, O.S. AbouZeid, H. Abramowicz, H. Abreu, Mogens Dam, Jørn Dines Hansen, Jørgen Beck Hansen, Stefania Xella, Peter Henrik Hansen, Troels Christian Petersen, Lotte Ansgaard Thomsen, Sascha Mehlhase, Almut Maria Pingel, Alejandro Alonso DiazJames William Monk, Gorm Aske Gram Krohn Galster, Lotte Ansgaard Thomsen, Ask Emil Løvschall-Jensen, Graig Wiglesworth, Lars Egholm Pedersen, Simon Holm Stark

Experimental Particle Physics

18 Citations (Scopus)

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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 (m_tt¯>0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2<|y_t|−|y_t¯|<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 language	English
Journal	Physics Letters B
Volume	756
Pages (from-to)	52-71
ISSN	0370-2693
DOIs	https://doi.org/10.1016/j.physletb.2016.02.055
Publication status	Published - 10 May 2016

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Aad, G., Abbott, B., Abdallah, J., Abdinov, O., Abellos, B., Aben, R., Abolins, M., AbouZeid, O. S., Abramowicz, H., Abreu, H., Dam, M., Hansen, J. D., Hansen, J. B., Xella, S., Hansen, P. H., Petersen, T. C., Thomsen, L. A., Mehlhase, S., Pingel, A. M., ... Stark, S. H. (2016). Measurement of the charge asymmetry in highly boosted top-quark pair production in root s=8 TeV pp collision data collected by the ATLAS experiment. Physics Letters B, 756, 52-71. https://doi.org/10.1016/j.physletb.2016.02.055

Aad, G, Abbott, B, Abdallah, J, Abdinov, O, Abellos, B, Aben, R, Abolins, M, AbouZeid, OS, Abramowicz, H, Abreu, H, Dam, M , Hansen, JD , Hansen, JB , Xella, S , Hansen, PH , Petersen, TC, Thomsen, LA, Mehlhase, S, Pingel, AM, Alonso Diaz, A, Monk, JW, Galster, GAGK, Thomsen, LA, Løvschall-Jensen, AE, Wiglesworth, G, Pedersen, LE & Stark, SH 2016, 'Measurement of the charge asymmetry in highly boosted top-quark pair production in root s=8 TeV pp collision data collected by the ATLAS experiment', Physics Letters B, vol. 756, pp. 52-71. https://doi.org/10.1016/j.physletb.2016.02.055

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title = "Measurement of the charge asymmetry in highly boosted top-quark pair production in root 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 = "G. Aad and B. Abbott and J. Abdallah and O. Abdinov and B. Abellos and R. Aben and M. Abolins and O.S. AbouZeid and H. Abramowicz and H. Abreu and Mogens Dam and Hansen, {J{\o}rn Dines} and Hansen, {J{\o}rgen Beck} and Stefania Xella and Hansen, {Peter Henrik} and Petersen, {Troels Christian} and Thomsen, {Lotte Ansgaard} and Sascha Mehlhase and Pingel, {Almut Maria} and {Alonso Diaz}, Alejandro and Monk, {James William} and Galster, {Gorm Aske Gram Krohn} and Thomsen, {Lotte Ansgaard} and L{\o}vschall-Jensen, {Ask Emil} and Graig Wiglesworth and Pedersen, {Lars Egholm} and Stark, {Simon Holm}",

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doi = "10.1016/j.physletb.2016.02.055",

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AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdinov, O.

AU - Abellos, B.

AU - Aben, R.

AU - Abolins, M.

AU - AbouZeid, O.S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Dam, Mogens

AU - Hansen, Jørn Dines

AU - Hansen, Jørgen Beck

AU - Xella, Stefania

AU - Hansen, Peter Henrik

AU - Petersen, Troels Christian

AU - Thomsen, Lotte Ansgaard

AU - Mehlhase, Sascha

AU - Pingel, Almut Maria

AU - Alonso Diaz, Alejandro

AU - Monk, James William

AU - Galster, Gorm Aske Gram Krohn

AU - Thomsen, Lotte Ansgaard

AU - Løvschall-Jensen, Ask Emil

AU - Wiglesworth, Graig

AU - Pedersen, Lars Egholm

AU - Stark, Simon Holm

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.

U2 - 10.1016/j.physletb.2016.02.055

DO - 10.1016/j.physletb.2016.02.055

M3 - Journal article

SN - 0370-2693

VL - 756

SP - 52

EP - 71

JO - Physics Letters B

JF - Physics Letters B

ER -

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

Abstract

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