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

• Main Authors: Bauer, Gerry P (Contributor), Choudalakis, Georgios (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Hahn, Kristian Allan (Contributor), Henderson, Conor (Contributor), Knuteson, Bruce O (Contributor), Makhoul, Khaldoun (Contributor), Paus, Christoph M. E. (Contributor), Xie, Si (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society (APS), 2018-11-14T18:15:04Z.
• Subjects: Article
• Online Access: Get fulltext

 We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9fb[superscript -1] of pp̄ collisions collected at √s = 1.96TeV 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[subscript top] = 171.9 ± 1.7(stat+JES)±1.1(othersyst) GeV/c[superscript 2] = 171.9 ± 2.0 GeV/c[superscript 2].