A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for ttˉ events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 inverse femtobarns 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.
Measurement of masses in the t t-bar system by kinematic endpoints in pp collisions at sqrt(s) = 7 TeV
CAVALLO, Nicola;FABOZZI, FRANCESCO;
2013-01-01
Abstract
A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for ttˉ events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 inverse femtobarns 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
