Measurement of masses in the t(t)over-tilde system by kinematic endpoints in pp collisions at root s=7 TeV


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

EUROPEAN PHYSICAL JOURNAL C, vol.73, no.7, 2013 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 7
  • Publication Date: 2013
  • Doi Number: 10.1140/epjc/s10052-013-2494-7
  • Title of Journal : EUROPEAN PHYSICAL JOURNAL C

Abstract

A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for t (t) over bar 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 root 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 M-t = 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.