Measurement of the top quark mass in the lepton+jets final state with the matrix element method
Physical Review D Particles Fields Gravitation and Cosmology 74:9 (2006)
Abstract:
We present a measurement of the top quark mass with the matrix element method in the lepton+jets final state. As the energy scale for calorimeter jets represents the dominant source of systematic uncertainty, the matrix element likelihood is extended by an additional parameter, which is defined as a global multiplicative factor applied to the standard energy scale. The top quark mass is obtained from a fit that yields the combined statistical and systematic jet energy scale uncertainty. Using a data set of 0.4fb-1 taken with the D0 experiment at Run II of the Fermilab Tevatron Collider, the mass of the top quark is measured using topological information to be: mtopℓ+jets(topo)=169. 2-7.4+5.0(stat+JES)-1.4+1.5(syst)GeV, and when information about identified b jets is included: mtopℓ+jets(b-tag)=170.3-4.5+4.1(stat+JES)-1.8+1.2(syst) GeV. The measurements yield a jet energy scale consistent with the reference scale. © 2006 The American Physical Society.Measurement of the tt̄ production cross section in pp̄ collisions at s=1.96TeV using secondary vertex b tagging
Physical Review D - Particles, Fields, Gravitation and Cosmology 74:11 (2006)
Abstract:
We report a new measurement of the tt̄ production cross section in pp̄ collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425pb-1 of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the tt̄ content of the sample by tagging b jets with a secondary vertex tagging algorithm, the tt̄ production cross section is measured to be σpp̄→tt̄+X=6.6±0.9(stat+syst) ±0.4(lum)pb. This cross section is the most precise D0 measurement to date for tt̄ production and is in good agreement with standard model expectations. © 2006 The American Physical Society.Online system for normalizing data acquired by the Fermilab DØ experiment
Journal of the Korean Physical Society 49:6 (2006) 2247-2252
Abstract:
The DØ experiment uses a dedicated data acquisition system to collect, archive, monitor, and distribute the information necessary to normalize triggered data for physics analyses. This system has been in place since the beginning of Run 2 of the Fermilab Tevatron collider in 2001 and provides real-time feedback on the instantaneous and triggered luminosities in the DØ and Tevatron control rooms, as well as the status reports needed for smooth operation of the experiment. This paper describes the architecture and the implementation of this system.Observation of B(s)0-->K+ K- and measurements of branching fractions of charmless two-body decays of B0 and B(s)0 mesons in pp collisions at square root of s = 1.96 TeV.
Phys Rev Lett 97:21 (2006) 211802
Abstract:
We search for decays of the type B(s)0-->h+ h'- (where h,h' = K or pi) in 180 pb(-1) of pp collisions collected at the Tevatron by the upgraded Collider Detector at Fermilab. We report the first observation of the new mode B(s)0-->K+ K- with a yield of 236+/-32 events, corresponding to (fs/fd) x B(B(s)0-->K+ K-)/B(B0-->K+ pi-) = 0.46+/-0.08stat+/-0.07syst, where fs/fd is the ratio of production fractions of B(s)0 and B0. We find results in agreement with world averages for the B0 modes, and set the following new limits at 90% C.L.: B(B(s)0-->K- pi+) < 5.6 x 10(-6) and B(B(s)0-->pi+ pi-) < 1.7 x 10(-6).Measurement of the CP-violation parameter of B0 mixing and decay with pp̄→μμX data
Physical Review D - Particles, Fields, Gravitation and Cosmology 74:9 (2006)