Measurement of masses in the tt̄ system by kinematic endpoints in pp collisions at √s = 7 TeV


Chatrchyan S., Khachatryan V., Sirunyan A., Tumasyan A., Adam W., Bergauer T., ...More

European Physical Journal C, vol.73, no.7, pp.1-28, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 7
  • Publication Date: 2013
  • Doi Number: 10.1140/epjc/s10052-013-2494-7
  • Journal Name: European Physical Journal C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-28
  • Yıldız Technical University Affiliated: Yes

Abstract

A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for tt̄ events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 fb-1 collected by the CMS experiment in pp collisions at √s = 7 TeV. The analysis is based on endpoint determinations in kinematic distributions. When the neutrino and W-boson masses are constrained to their world-average values, a top-quark mass value of Mt = 173.9 ± 0.9 (stat)+1.7 -2.1(syst.) GeV is obtained. When such constraints are not used, the three particle masses are obtained in a simultaneous fit. In this unconstrained mode the study serves as a test of mass determination methods that may be used in beyond standard model physics scenarios where several masses in a decay chain may be unknown and undetected particles lead to underconstrained kinematics. © 2013 CERN for the benefit of the CMS collaboration.