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

Khachatryan, Vardan

doi:10.1007/JHEP04(2016)073

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

Journal Article · Wed Apr 13 00:00:00 EDT 2016 · Journal of High Energy Physics (Online)

DOI:https://doi.org/10.1007/JHEP04(2016)073· OSTI ID:1230033

Khachatryan, Vardan ^[1]

Yerevan Physics Inst. (YerPhI) (Armenia). et al.

Our 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 8 TeV 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. Furthermore, 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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Research Organization:: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Sponsoring Organization:: USDOE Office of Science (SC), High Energy Physics (HEP)

Contributing Organization:: CMS Collaboration

Grant/Contract Number:: AC02-07CH11359

OSTI ID:: 1230033

Report Number(s):: FERMILAB-PUB-15-518-CMS; arXiv eprint number arXiv:1511.02138

Journal Information:: Journal of High Energy Physics (Online), Vol. 2016, Issue 73; ISSN 1029-8479

Publisher:: Springer BerlinCopyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 20 works

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References (34)

Measurement of the $t$ -Channel Single Top Quark Production Cross Section in $p p$ Collisions at $\sqrt{s} = 7 TeV$ Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M. Physical Review Letters, Vol. 107, Issue 9 https://doi.org/10.1103/PhysRevLett.107.091802	journal	August 2011
W polarisation beyond helicity fractions in top quark decays Aguilar-Saavedra, J. A.; Bernabéu, J. Nuclear Physics B, Vol. 840, Issue 1-2 https://doi.org/10.1016/j.nuclphysb.2010.07.012	journal	November 2010
The anti- k _t jet clustering algorithm Cacciari, Matteo; Salam, Gavin P.; Soyez, Gregory Journal of High Energy Physics, Vol. 2008, Issue 04 https://doi.org/10.1088/1126-6708/2008/04/063	journal	April 2008
Method for simulating electroweak top-quark production events in the NLO approximation: SingleTop event generator Boos, E. E.; Bunichev, V. E.; Dudko, L. V. Physics of Atomic Nuclei, Vol. 69, Issue 8 https://doi.org/10.1134/S1063778806080084	journal	August 2006
Single top quark production at LHC with anomalous Wtb couplings Aguilar-Saavedra, J. A. Nuclear Physics B, Vol. 804, Issue 1-2 https://doi.org/10.1016/j.nuclphysb.2008.06.013	journal	November 2008
A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX Alioli, Simone; Nason, Paolo; Oleari, Carlo Journal of High Energy Physics, Vol. 2010, Issue 6 https://doi.org/10.1007/JHEP06(2010)043	journal	June 2010
MCFM for the Tevatron and the LHC Campbell, John M.; Ellis, R. K. Nuclear Physics B - Proceedings Supplements, Vol. 205-206 https://doi.org/10.1016/j.nuclphysbps.2010.08.011	journal	August 2010
$W + n$ -Jet Predictions at the Large Hadron Collider at Next-To-Leading Order Matched with a Parton Shower Höche, Stefan; Krauss, Frank; Schönherr, Marek Physical Review Letters, Vol. 110, Issue 5 https://doi.org/10.1103/PhysRevLett.110.052001	journal	January 2013
Measurement of the differential cross section for top quark pair production in pp collisions at $$\sqrt{s} = 8\,\text {TeV} $$ s = 8 TeV Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A. The European Physical Journal C, Vol. 75, Issue 11 https://doi.org/10.1140/epjc/s10052-015-3709-x	journal	November 2015
PYTHIA 6.4 physics and manual Sjöstrand, Torbjörn; Mrenna, Stephen; Skands, Peter Journal of High Energy Physics, Vol. 2006, Issue 05 https://doi.org/10.1088/1126-6708/2006/05/026	journal	May 2006
V - A tests through leptons from polarised top quarks Jeżabek, M.; Kühn, J. H. Physics Letters B, Vol. 329, Issue 2-3 https://doi.org/10.1016/0370-2693(94)90779-X	journal	June 1994
Measurement of the charge asymmetry in top-quark pair production in proton–proton collisions at <mml:math altimg="si1.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn><mml:mtext> </mml:mtext><mml:mtext>TeV</mml:mtext></mml:math> Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M. Physics Letters B, Vol. 709, Issue 1-2 https://doi.org/10.1016/j.physletb.2012.01.078	journal	March 2012
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations Alwall, J.; Frederix, R.; Frixione, S. Journal of High Energy Physics, Vol. 2014, Issue 7 https://doi.org/10.1007/JHEP07(2014)079	journal	July 2014
FastJet user manual: (for version 3.0.2) Cacciari, Matteo; Salam, Gavin P.; Soyez, Gregory The European Physical Journal C, Vol. 72, Issue 3 https://doi.org/10.1140/epjc/s10052-012-1896-2	journal	March 2012
Parton distributions with LHC data Ball, Richard D.; Bertone, Valerio; Carrazza, Stefano Nuclear Physics B, Vol. 867, Issue 2 https://doi.org/10.1016/j.nuclphysb.2012.10.003	journal	February 2013
Single top quark production at the LHC: Understanding spin Mahlon, Gregory; Parke, Stephen Physics Letters B, Vol. 476, Issue 3-4 https://doi.org/10.1016/S0370-2693(00)00149-0	journal	March 2000
Top++: A program for the calculation of the top-pair cross-section at hadron colliders Czakon, Michał; Mitov, Alexander Computer Physics Communications, Vol. 185, Issue 11 https://doi.org/10.1016/j.cpc.2014.06.021	journal	November 2014
TAUOLA - a library of Monte Carlo programs to simulate decays of polarized τ leptons Jadach, Stanisław; Kühn, Johann H.; Wa̧s, Zbigniew Computer Physics Communications, Vol. 64, Issue 2 https://doi.org/10.1016/0010-4655(91)90038-M	journal	May 1991
Extended parameterisations for MSTW PDFs and their effect on lepton charge asymmetry from W decays Martin, A. D.; Mathijssen, A. J. Th. M.; Stirling, W. J. The European Physical Journal C, Vol. 73, Issue 2 https://doi.org/10.1140/epjc/s10052-013-2318-9	journal	February 2013
A minimal set of top anomalous couplings Aguilar-Saavedra, J. A. Nuclear Physics B, Vol. 812, Issue 1-2 https://doi.org/10.1016/j.nuclphysb.2008.12.012	journal	May 2009
Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions Alwall, J.; Höche, S.; Krauss, F. The European Physical Journal C, Vol. 53, Issue 3 https://doi.org/10.1140/epjc/s10052-007-0490-5	journal	December 2007
An introduction to PYTHIA 8.2 Sjöstrand, Torbjörn; Ask, Stefan; Christiansen, Jesper R. Computer Physics Communications, Vol. 191 https://doi.org/10.1016/j.cpc.2015.01.024	journal	June 2015
Event generation with SHERPA 1.1 Gleisberg, T.; Höche, S.; Krauss, F. Journal of High Energy Physics, Vol. 2009, Issue 02 https://doi.org/10.1088/1126-6708/2009/02/007	journal	February 2009
Measurement of differential top-quark-pair production cross sections in pp collisions at $\sqrt{s} = 7\ \mathrm{TeV}$ Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M. The European Physical Journal C, Vol. 73, Issue 3 https://doi.org/10.1140/epjc/s10052-013-2339-4	journal	March 2013
MadEvent: automatic event generation with MadGraph Maltoni, Fabio; Stelzer, Tim Journal of High Energy Physics, Vol. 2003, Issue 02 https://doi.org/10.1088/1126-6708/2003/02/027	journal	February 2003
Geant4—a simulation toolkit Agostinelli, S.; Allison, J.; Amako, K. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3 https://doi.org/10.1016/S0168-9002(03)01368-8	journal	July 2003
FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order Gavin, Ryan; Li, Ye; Petriello, Frank Computer Physics Communications, Vol. 182, Issue 11 https://doi.org/10.1016/j.cpc.2011.06.008	journal	November 2011
Matching NLO QCD computations with parton shower simulations: the POWHEG method Frixione, Stefano; Nason, Paolo; Oleari, Carlo Journal of High Energy Physics, Vol. 2007, Issue 11 https://doi.org/10.1088/1126-6708/2007/11/070	journal	November 2007
Matching matrix elements and shower evolution for top-pair production in hadronic collisions Mangano, Michelangelo L.; Moretti, Mauro; Piccinini, Fulvio Journal of High Energy Physics, Vol. 2007, Issue 01 https://doi.org/10.1088/1126-6708/2007/01/013	journal	January 2007
Identification of b-quark jets with the CMS experiment collaboration, The CMS Journal of Instrumentation, Vol. 8, Issue 04 https://doi.org/10.1088/1748-0221/8/04/P04013	journal	April 2013
Performance of CMS muon reconstruction in pp collision events at √s = 7 TeV collaboration, The CMS Journal of Instrumentation, Vol. 7, Issue 10 https://doi.org/10.1088/1748-0221/7/10/P10002	journal	October 2012
Determination of jet energy calibration and transverse momentum resolution in CMS collaboration, The CMS Journal of Instrumentation, Vol. 6, Issue 11 https://doi.org/10.1088/1748-0221/6/11/P11002	journal	November 2011
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations Alwall, J.; Frederix, R.; Frixione, S. Springer https://doi.org/10.5167/uzh-107572	text	January 2014
Event generation with SHERPA 1.1 Gleisberg, T.; Höche, S.; Krauss, F. Institute of Physics Publishing https://doi.org/10.5167/uzh-32078	text	January 2009

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Top-quark physics at the Large Hadron Collider Cristinziani, Markus; Mulders, Martijn Journal of Physics G: Nuclear and Particle Physics, Vol. 44, Issue 6 https://doi.org/10.1088/1361-6471/44/6/063001	journal	May 2017
$T$ -odd correlations in polarized top quark decays in the sequential decay $t (↑) \to X_{b} + W^{+} (\to ℓ^{+} + ν_{ℓ})$ and in the quasi-three-body decay $t (↑) \to X_{b} + ℓ^{+} + ν_{ℓ}$ Fischer, M.; Groote, S.; Körner, J. G. Physical Review D, Vol. 97, Issue 9 https://doi.org/10.1103/physrevd.97.093001	journal	May 2018
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