We present a direct measurement of the mass difference between t and t̅ quarks using tt̅ candidate events in the lepton+jets channel, collected with the CDF II detector at Fermilab’s 1.96 TeV Tevatron pp̅ Collider. We make an event by event estimate of the mass difference to construct templates for top quark pair signal events and background events. The resulting mass difference distribution of data is compared to templates of signals and background using a maximum likelihood fit. From a sample corresponding to an integrated luminosity of 5.6 fb-1, we measure a mass difference, ΔMtop=Mt-Mt̅ =-3.3±1.4(stat)±1.0(syst) GeV/c2, approximately 2 standard deviations away from the CPT hypothesis of zero mass difference.
Measurement of the Mass Difference between t and t̅ Quarks
PAGLIARONE, Carmine Elvezio;
2011-01-01
Abstract
We present a direct measurement of the mass difference between t and t̅ quarks using tt̅ candidate events in the lepton+jets channel, collected with the CDF II detector at Fermilab’s 1.96 TeV Tevatron pp̅ Collider. We make an event by event estimate of the mass difference to construct templates for top quark pair signal events and background events. The resulting mass difference distribution of data is compared to templates of signals and background using a maximum likelihood fit. From a sample corresponding to an integrated luminosity of 5.6 fb-1, we measure a mass difference, ΔMtop=Mt-Mt̅ =-3.3±1.4(stat)±1.0(syst) GeV/c2, approximately 2 standard deviations away from the CPT hypothesis of zero mass difference.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
