We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb(-1) of p (p) over bar collisions collected at root s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a nonparametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton + jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be M(top)=(171.9 +/- 1.7(stat + JES) +/- 1.1(other syst)) GeV/c(2)=(171.9 +/- 2.0) GeV/c(2).

First simultaneous measurement of the top quark mass in the lepton+jets and dilepton channels at CDF

CIOCCI, MARIA AGNESE;DONATI, SIMONE;
2009-01-01

Abstract

We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb(-1) of p (p) over bar collisions collected at root s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a nonparametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton + jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be M(top)=(171.9 +/- 1.7(stat + JES) +/- 1.1(other syst)) GeV/c(2)=(171.9 +/- 2.0) GeV/c(2).
2009
T., Aaltonen; J., Adelman; T., Akimoto; M., Albrow; B., González; S., Amerio; D., Amidei; A., Anastassov; A., Annovi; J., Antos; G., Apollinari; A., A...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/829033
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