Measurement of top quark polarisation in t-channel single top quark production

被引：24

作者：

Khachatryan, V. ^{[1
]}

Sirunyan, A. M. ^{[1
]}

Tumasyan, A. ^{[1
]}

Adam, W. ^{[2
]}

Asilar, E. ^{[2
]}

Bergauer, T. ^{[2
]}

Brandstetter, J. ^{[2
]}

Brondolin, E. ^{[2
]}

Dragicevic, M. ^{[2
]}

Eroe, J. ^{[2
,41
]}

Flechl, M. ^{[2
]}

Friedl, M. ^{[2
]}

Fruehwirth, R. ^{[2
,191
]}

Ghete, V. M. ^{[2
]}

Hartl, C. ^{[2
]}

Hoermann, N. ^{[2
]}

Hrubec, J. ^{[2
]}

Jeitler, M. ^{[2
,191
]}

Knuenz, V. ^{[2
]}

Koenig, A. ^{[2
]}

Krammer, M. ^{[2
,191
]}

Kraetschmer, I. ^{[2
]}

Liko, D. ^{[2
]}

Matsushita, T. ^{[2
]}

Mikulec, I. ^{[2
]}

Rabady, D. ^{[2
,192
]}

Rahbaran, B. ^{[2
]}

Rohringer, H. ^{[2
]}

Schieck, J. ^{[2
,191
]}

Schoefbeck, R. ^{[2
]}

Strauss, J. ^{[2
]}

Treberer-Treberspurg, W. ^{[2
]}

Waltenberger, W. ^{[2
]}

Wulz, C-E ^{[2
,191
]}

Mossolov, V. ^{[3
]}

Shumeiko, N. ^{[3
]}

Gonzalez, J. Suarez ^{[3
]}

Alderweireldt, S. ^{[4
]}

Cornelis, T. ^{[4
]}

De Wolf, E. A. ^{[4
]}

Janssen, X. ^{[4
]}

Knutsson, A. ^{[4
]}

Lauwers, J. ^{[4
]}

Luyckx, S. ^{[4
]}

Van de Klundert, M. ^{[4
]}

Van Haevermaet, H. ^{[4
]}

Van Mechelen, P. ^{[4
]}

Van Remortel, N. ^{[4
]}

Van Spilbeeck, A. ^{[4
]}

Abu Zeid, S. ^{[5
]}

机构：

[1] Yerevan Phys Inst, Yerevan 375036, Armenia

[2] OeAW, Inst Hochenergiephys, Vienna, Austria

[3] Natl Ctr Particle & High Energy Phys, Minsk, BELARUS

[4] Univ Antwerp, B-2020 Antwerp, Belgium

[5] Vrije Univ Brussel, Brussels, Belgium

[6] Univ Libre Bruxelles, Brussels, Belgium

[7] Univ Ghent, B-9000 Ghent, Belgium

[8] Catholic Univ Louvain, Louvain La Neuve, Belgium

[9] Univ Mons, B-7000 Mons, Belgium

[10] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil

[11] Univ Estado Rio de Janeiro, BR-20550011 Rio De Janeiro, Brazil

[12] Univ Estadual Paulista, Sao Paulo, Brazil

[13] Univ Fed ABC, Sao Paulo, Brazil

[14] Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, Sofia, Bulgaria

[15] Univ Sofia, BU-1126 Sofia, Bulgaria

[16] Inst High Energy Phys, Beijing 100039, Peoples R China

[17] Peking Univ, State Key Lab Nucl Phys & Technol, Beijing 100871, Peoples R China

[18] Univ Los Andes, Bogota, Colombia

[19] Univ Split, Fac Elect Engn Mech Engn & Naval Architecture, Split, Croatia

[20] Univ Split, Fac Sci, Split, Croatia

[21] Rudjer Boskovic Inst, Zagreb, Croatia

[22] Rudjer Boskovic Inst, Zagreb, Croatia

[23] Univ Cyprus, CY-1678 Nicosia, Cyprus

[24] Charles Univ Prague, Prague, Czech Republic

[25] Acad Sci Res & Technol Arab Republ Egypt, Egyptian Network High Energy Phys, Cairo, Egypt

[26] NICPB, Tallinn, Estonia

[27] Univ Helsinki, Dept Phys, Helsinki, Finland

[28] Helsinki Inst Phys, Helsinki, Finland

[29] Lappeenranta Univ Technol, Lappeenranta, Finland

[30] CEA Saclay, DSM IRFU, F-91191 Gif Sur Yvette, France

[31] Ecole Polytech, CNRS, IN2P3, Lab Leprince Ringuet, F-91128 Palaiseau, France

[32] Univ Haute Alsace Mulhouse, Univ Strasbourg, Inst Pluridisciplinaire Hubert Curien, CNRS,IN2P3, Strasbourg, France

[33] CNRS, IN2P3, Inst Natl Phys Nucl & Phys Particules, Ctr Calcul, Villeurbanne, France

[34] Univ Lyon 1, Univ Lyon, Inst Phys Nucl Lyon, CNRS,IN2P3, F-69622 Villeurbanne, France

[35] Georgian Tech Univ, Tbilisi, Georgia

[36] Tbilisi State Univ, Tbilisi, Georgia

[37] Rhein Westfal TH Aachen, Inst Phys 1, Aachen, Germany

[38] Rhein Westfal TH Aachen, Phys Inst A 3, Aachen, Germany

[39] Rhein Westfal TH Aachen, Phys Inst B 3, Aachen, Germany

[40] DESY, Hamburg, Germany

[41] Univ Hamburg, Hamburg, Germany

[42] Univ Karlsruhe, Inst Expt Kernphys, Karlsruhe, Germany

[43] NCSR Demokritos, INPP, Aghia Paraskevi, Greece

[44] Univ Athens, Athens, Greece

[45] Univ Ioannina, GR-45110 Ioannina, Greece

[46] Wigner Res Ctr Phys, Budapest, Hungary

[47] Inst Nucl Res ATOMKI, Debrecen, Hungary

[48] Univ Debrecen, Debrecen, Hungary

[49] Natl Inst Sci Educ & Res, Bhubaneswar, Orissa, India

[50] Panjab Univ, Chandigarh 160014, India

来源：

JOURNAL OF HIGH ENERGY PHYSICS | 2016年 / 04期

基金：

美国国家科学基金会; 俄罗斯基础研究基金会; 英国科学技术设施理事会; 奥地利科学基金会; 欧洲研究理事会; 巴西圣保罗研究基金会; 中国国家自然科学基金; 芬兰科学院; 新加坡国家研究基金会;

关键词：

Hadron-Hadron scattering (experiments); Top physics; LHC;

D O I：

10.1007/JHEP04(2016)073

中图分类号：

O412 [相对论、场论]; O572.2 [粒子物理学];

学科分类号：

摘要：

A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8TeV corresponding to an integrated luminosity of 19.7 fb(-1). A high-purity sample of t-channel single top quark events with an isolated muon is selected. Signal and background components are estimated using a fit to data. A differential cross section measurement, corrected for detector effects, of an angular observable sensitive to the top quark polarisation is performed. The differential distribution is used to extract a top quark spin asymmetry of 0.26 +/- 0.03(stat) +/- 0.10(syst), which is compatible with a p-value of 4.6% with the standard model prediction of 0.44.

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