Skip to main content
Log in

Measurement of the top-quark mass in \(\mathrm{t}\overline{\mathrm{t}}\) events with dilepton final states in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}\)

  • Regular Article - Experimental Physics
  • Published:
The European Physical Journal C Aims and scope Submit manuscript

Abstract

The top-quark mass is measured in proton-proton collisions at \(\sqrt{s} = 7\ \mbox{TeV}\) using a data sample corresponding to an integrated luminosity of 5.0 fb−1 collected by the CMS experiment at the LHC. The measurement is performed in the dilepton decay channel \(\mathrm{t}\overline{\mathrm{t}}\rightarrow(\ell^{+}\nu_{\ell}\mathrm{b})\,(\ell^{-}\overline{\nu}_{\ell}\overline{\mathrm{b}})\), where =e,μ. Candidate top-quark decays are selected by requiring two leptons, at least two jets, and imbalance in transverse momentum. The mass is reconstructed with an analytical matrix weighting technique using distributions derived from simulated samples. Using a maximum-likelihood fit, the top-quark mass is determined to be 172.5±0.4 (stat.)±1.5 (syst.) GeV.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  1. ALEPH, CDF, D0, DELPHI, L3, OPAL, SLD Collaborations, the LEP Electroweak Working Group, the Tevatron Electroweak Working Group, and the SLD Electroweak and Heavy Flavour Groups, Precision electroweak measurements and constraints on the Standard Model (2010). arXiv:1012.2367

  2. H. Flächer et al., Revisiting the global electroweak fit of the Standard Model and beyond with Gfitter. Eur. Phys. J. C 60, 543 (2009). doi:10.1140/epjc/s10052-009-0966-6, arXiv:0811.0009

    Article  ADS  Google Scholar 

  3. CDF and D0 Collaborations, Combination of the top-quark mass measurements from the Tevatron collider. Phys. Rev. D (2012 submitted). arXiv:1207.1069

  4. CDF Collaboration, Top quark mass measurement using the template method at CDF. Phys. Rev. D 83, 111101 (2011). doi:10.1103/PhysRevD.83.111101, arXiv:1105.0192

    Article  Google Scholar 

  5. D0 Collaboration, Measurement of the top quark mass in \(p \bar{p}\) collisions using events with two leptons. Phys. Rev. D 86, 051103 (2012). doi:10.1103/PhysRevD.86.051103, arXiv:1201.5172

    Article  Google Scholar 

  6. CMS Collaboration, Measurement of the \(\mathrm{t}\overline{\mathrm{t}}\) production cross section and the top quark mass in the dilepton channel in pp collisions at \(\sqrt{s}=7~\mbox{TeV}\). J. High Energy Phys. 1107, 049 (2011). doi:10.1007/JHEP07(2011)049, arXiv:1105.5661

    ADS  Google Scholar 

  7. ATLAS Collaboration, Measurement of the top quark mass with the template method in the \(\mathrm{t}\overline{\mathrm{t}}\to\) lepton + jets channel using ATLAS data. Eur. Phys. J. C 72, 2046 (2012). doi:10.1140/epjc/s10052-012-2046-6, arXiv:1203.5755

    Article  ADS  Google Scholar 

  8. CMS Collaboration, Measurement of the top-quark mass in the lepton + jets final states in pp collisions at \(\sqrt{s} = 7~\mathrm{TeV}\). J. High Energy Phys. (2012 submitted). arXiv:1209.2319

  9. CMS Collaboration, The CMS experiment at the CERN LHC. J. Instrum. 03, S08004 (2008). doi:10.1088/1748-0221/3/08/S08004

    Article  Google Scholar 

  10. J. Alwall et al., MadGraph 5: going beyond. J. High Energy Phys. 1106, 128 (2011). doi:10.1007/JHEP06(2011)128, arXiv:1106.0522

    Article  ADS  Google Scholar 

  11. T. Sjöstrand, S. Mrenna, P.Z. Skands, PYTHIA 6.4 physics and manual. J. High Energy Phys. 05, 026 (2006). doi:10.1088/1126-6708/2006/05/026, arXiv:hep-ph/0603175

    Article  ADS  Google Scholar 

  12. M.L. Mangano et al., Matching matrix elements and shower evolution for top-quark production in hadronic collisions. J. High Energy Phys. 01, 013 (2007). doi:10.1088/1126-6708/2007/01/013, arXiv:hep-ph/0611129

    Article  ADS  Google Scholar 

  13. CMS Collaboration, Measurement of the underlying event activity at the LHC with \(\sqrt{s}= 7~\mbox{TeV}\) and comparison with \(\sqrt{s} = 0.9~\mbox{TeV}\). J. High Energy Phys. 09, 109 (2011). doi:10.1007/JHEP09(2011)109, arXiv:1107.0330

    ADS  Google Scholar 

  14. P.M. Nadolsky et al., Implications of CTEQ global analysis for collider observables. Phys. Rev. D 78, 013004 (2008). doi:10.1103/PhysRevD.78.013004, arXiv:0802.0007

    Article  ADS  Google Scholar 

  15. N. Davidson et al., Universal interface of TAUOLA technical and physics documentation. Comput. Phys. Commun. 183, 821 (2012). doi:10.1016/j.cpc.2011.12.009, arXiv:1002.0543

    Article  ADS  Google Scholar 

  16. S. Frixione, P. Nason, C. Oleari, Matching NLO QCD computations with parton shower simulations: the POWHEG method. J. High Energy Phys. 11, 070 (2007). doi:10.1088/1126-6708/2007/11/070, arXiv:0709.2092

    Article  ADS  Google Scholar 

  17. U. Langenfeld, S. Moch, P. Uwer, Measuring the running top-quark mass. Phys. Rev. D 80, 054009 (2009). doi:10.1103/PhysRevD.80.054009, arXiv:0906.5273

    Article  ADS  Google Scholar 

  18. M. Aliev et al., HATHOR: HAdronic Top and Heavy quarks crOss section calculatoR. Comput. Phys. Commun. 182, 1034 (2011). doi:10.1016/j.cpc.2010.12.040, arXiv:1007.1327

    Article  ADS  MATH  Google Scholar 

  19. N. Kidonakis, Two-loop soft anomalous dimensions for single top quark associated production with a W or H . Phys. Rev. D 82, 054018 (2010). doi:10.1103/PhysRevD.82.054018, arXiv:1005.4451

    Article  ADS  Google Scholar 

  20. K. Melnikov, F. Petriello, Electroweak gauge boson production at hadron colliders through \(O(\alpha_{S}^{2})\). Phys. Rev. D 74, 114017 (2006). doi:10.1103/PhysRevD.74.114017, arXiv:hep-ph/0609070

    Article  ADS  Google Scholar 

  21. Particle Data Group Collaboration, Review of particle physics. Phys. Rev. D 86, 010001 (2012). doi:10.1103/PhysRevD.86.010001

    Article  Google Scholar 

  22. J.M. Campbell, R.K. Ellis, C. Williams, Vector boson pair production at the LHC. J. High Energy Phys. 1107, 018 (2011). doi:10.1007/JHEP07(2011)018, arXiv:1105.0020

    Article  ADS  Google Scholar 

  23. GEANT4 Collaboration, GEANT4: a simulation toolkit. Nucl. Instrum. Methods Phys. Res., Sect. A, Accel. Spectrom. Detect. Assoc. Equip. 506, 250 (2003). doi:10.1016/S0168-9002(03)01368-8

    Article  ADS  Google Scholar 

  24. CMS Collaboration, Commissioning of the particle-flow reconstruction in minimum-bias and jet events from pp collisions at 7 TeV. CMS Physics Analysis Summary CMS-PAS-PFT-10-002 (2010)

  25. M. Cacciari, G.P. Salam, G. Soyez, The anti-k T jet clustering algorithm. J. High Energy Phys. 0804, 063 (2008). doi:10.1088/1126-6708/2008/04/063, arXiv:0802.1189

    Article  ADS  Google Scholar 

  26. CMS Collaboration, Determination of jet energy calibration and transverse momentum resolution in CMS. J. Instrum. 06, P11002 (2011). doi:10.1088/1748-0221/6/11/P11002, arXiv:1107.4277

    Article  Google Scholar 

  27. CMS Collaboration, b-Jet identification in the CMS experiment. CMS Physics Analysis Summary CMS-PAS-BTV-11-004 (2012)

  28. CMS Collaboration, Measurement of btagging efficiency using \(\mathrm{t}\bar{\mathrm {t}}\) events. CMS Physics Analysis Summary CMS-PAS-BTV-11-003 (2012)

  29. CMS Collaboration, Measurement of the \(t\bar{t}\) production cross section in the dilepton channel in pp collisions at \(\sqrt{s} = 7~\mbox{TeV}\). J. High Energy Phys. (2012 submitted). arXiv:1208.2671 [hep-ex]

  30. CMS Collaboration, Measurement of the mass difference between top and antitop quarks. J. High Energy Phys. 1206, 109 (2012). doi:10.1007/JHEP06(2012)109, arXiv:1204.2807

    ADS  Google Scholar 

  31. D0 Collaboration, Measurement of the top quark mass using dilepton events. Phys. Rev. Lett. 80, 2063 (1998). doi:10.1103/PhysRevLett.80.2063, arXiv:hep-ex/9706014

    Article  Google Scholar 

  32. CDF Collaboration, Measurement of the top quark mass and \(\mathrm{t}\overline {\mathrm{t}}\) production cross section from dilepton events at the collider detector at Fermilab. Phys. Rev. Lett. 80, 2779 (1998). doi:10.1103/PhysRevLett.80.2779, arXiv:hep-ex/9802017

    Article  Google Scholar 

  33. L. Sonnenschein, Analytical solution of \(t \bar{t}\) dilepton equations. Phys. Rev. D 73(5), 054015 (2006). doi:10.1103/PhysRevD.73.054015, arXiv:hep-ph/0603011

    Article  ADS  Google Scholar 

  34. L. Sonnenschein, Erratum. Phys. Rev. D 78(7), 079902 (2008). doi:10.1103/PhysRevD.78.079902

    Article  ADS  Google Scholar 

  35. L. Sonnenschein, Algebraic approach to solve \(t \bar{t}\) dilepton equations. Phys. Rev. D 72, 095020 (2005). doi:10.1103/PhysRevD.72.095020, arXiv:hep-ph/0510100

    Article  ADS  Google Scholar 

  36. R.H. Dalitz, G.R. Goldstein, Decay and polarization properties of the top quark. Phys. Rev. D 45, 1531 (1992). doi:10.1103/PhysRevD.45.1531

    Article  ADS  Google Scholar 

  37. H.-L. Lai et al., Uncertainty induced by QCD coupling in the CTEQ global analysis of parton distributions. Phys. Rev. D 82, 054021 (2010). doi:10.1103/PhysRevD.78.013004, arXiv:1004.4624

    Article  ADS  Google Scholar 

  38. M. Botje et al., The PDF4LHC working group interim recommendations. arXiv:1101.0538 (2011)

  39. D. Wicke, P.Z. Skands, Non-perturbative QCD effects and the top mass at the Tevatron. Nuovo Cimento B 123, S1 (2008). doi:10.1393/ncb/i2009-10749-y, arXiv:0807.3248

    ADS  Google Scholar 

  40. P.Z. Skands, Tuning Monte Carlo generators: the Perugia tunes. Phys. Rev. D 82, 074018 (2010). doi:10.1103/PhysRevD.82.074018, arXiv:1005.3457

    Article  ADS  Google Scholar 

  41. CMS Collaboration, Search for neutral Higgs bosons decaying to tau pairs in pp collisions at \(\sqrt{s}=7~\mathrm{TeV}\). Phys. Lett. B 713, 68 (2012). doi:10.1016/j.physletb.2012.05.028, arXiv:1202.4083

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC machine. We thank the technical and administrative staff at CERN and other CMS institutes, and acknowledge support from: BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA).

Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Austrian Science Fund (FWF); the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Council of Science and Industrial Research, India; the Compagnia di San Paolo (Torino); and the HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund.

Open Access

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

Author information

Authors and Affiliations

Authors

Consortia

Rights and permissions

Reprints and permissions

About this article

Cite this article

The CMS Collaboration., Chatrchyan, S., Khachatryan, V. et al. Measurement of the top-quark mass in \(\mathrm{t}\overline{\mathrm{t}}\) events with dilepton final states in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}\) . Eur. Phys. J. C 72, 2202 (2012). https://doi.org/10.1140/epjc/s10052-012-2202-z

Download citation

  • Received:

  • Revised:

  • Published:

  • DOI: https://doi.org/10.1140/epjc/s10052-012-2202-z

Navigation