We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the full Tevatron run II data set of root s = 1.96 TeV proton-antiproton collisions recorded by the CDF II detector. The top quark mass and the mass of the hadronically decaying W boson are reconstructed for each event and compared with distributions derived from simulated signal and background samples to extract the top quark width (Gamma(top)) and the energy scale of the calorimeter jets with in situ calibration. For a top quark mass M-top = 172.5 GeV/c(2), we find 1.10 < Gamma(top) < 4.05 GeV at 68% confidence level, which is in agreement with the standard model expectation of 1.3 GeV and is the most precise direct measurement of the top quark width to date.
T. Aaltonen, S. Amerio, D. Amidei, A. Anastassov, A. Annovi, J. Antos, et al. (2013). Direct Measurement of the Total Decay Width of the Top Quark. PHYSICAL REVIEW LETTERS, 111, 202001-1-202001-8 [10.1103/PhysRevLett.111.202001].
Direct Measurement of the Total Decay Width of the Top Quark
BRIGLIADORI, LUCA;CASTRO, ANDREA;DENINNO, MARIA MADDALENA;MAZZANTI, PAOLO;MOGGI, NICCOLO';MUSSINI, MANUEL;RIMONDI, FRANCO;ZUCCHELLI, STEFANO
2013
Abstract
We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the full Tevatron run II data set of root s = 1.96 TeV proton-antiproton collisions recorded by the CDF II detector. The top quark mass and the mass of the hadronically decaying W boson are reconstructed for each event and compared with distributions derived from simulated signal and background samples to extract the top quark width (Gamma(top)) and the energy scale of the calorimeter jets with in situ calibration. For a top quark mass M-top = 172.5 GeV/c(2), we find 1.10 < Gamma(top) < 4.05 GeV at 68% confidence level, which is in agreement with the standard model expectation of 1.3 GeV and is the most precise direct measurement of the top quark width to date.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.