Determination of the strong phase in D0→K+π- Using quantum-correlated measurements
Physical Review Letters 100:22 (2008)
Abstract:
We exploit the quantum coherence between pair-produced D0 and D̄0 in ψ(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase δ between D0→K+π- and D̄0→K+π-. Using 281pb-1 of e+e- collision data collected with the CLEO-c detector at Ecm=3.77GeV, as well as branching fraction input and time-integrated measurements of RM(x2+y2)/2 and RWSΓ(D0→K+π-)/Γ(D̄0→K+π-) from other experiments, we find cosδ=1.03-0.17+0.31±0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of cosδ=1.10±0.35±0.07, as well as xsinδ=(4.4-1.8+2. 7±2.9)×10-3 and δ=(22-12-11+11+9)°. © 2008 The American Physical Society.Measurement of exclusive D meson decays to η and η′ final states and SU(3) amplitude analysis
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:9 (2008)
Abstract:
Using 281pb-1 of data collected with the CLEO-c detector, we present new measurements of Cabibbo-suppressed decays of D0 and D+ mesons to η and η′ final states. We make first observations of D0→η′ π0, ηη, ηη′, and ηπ+π-, and find evidence for D+→ηπ+π0, D+→η′π+π0, and D0→η′π+π-. We also report on improved measurements of D0→ηπ0, D+→ηπ+, and D+→η′π+. Using the measured two-body Cabibbo-suppressed decays, we extract amplitudes for specific flavor topologies and compare them to those from Cabibbo-favored decays. © 2008 The American Physical Society.Absolute branching fractions of Cabibbo-suppressed D→KK̄ decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:9 (2008)
Abstract:
Using 281pb-1 of data collected with the CLEO-c detector at the ψ(3770) resonance, we have studied Cabibbo-suppressed decays of D mesons to final states with two kaons. We present results for the absolute branching fractions of the modes D0→K+K-, D0→KS0KS0, and D+→K+KS0. We measure B(D0→K+K-)=(4.08±0.08±0.09)×10-3, B(D0→KS0KS0)=(1. 46±0.32±0.09)×10-4, and B(D+→K+KS0)=(3.14±0. 09±0.08)×10-3. We also determine the ratio B(D0→K+K-)/ B(D0→π+π-)=2.89±0.05±0.06. For each measurement, the first uncertainty is statistical and the second uncertainty is systematic. © 2008 The American Physical Society.Measurement of the tt̄ production cross section in pp̄ collisions at s=1.96TeV
Physical Review Letters 100:19 (2008)
Abstract:
We measure the tt̄ production cross section in pp̄ collisions at s=1.96TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background: b tagging and a kinematic likelihood discriminant. Based on 0.9fb-1 of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure σtt̄=7.62±0.85pb, assuming the current world average mt=172.6GeV. We compare our cross section measurement with theory predictions to determine a value for the top-quark mass of 170±7GeV. © 2008 The American Physical Society.First observation of the decay Ds+→pn̄
Physical Review Letters 100:18 (2008)