Determination of the D0→K+π- relative strong phase using quantum-correlated measurements in e+e-→D0D̄0 at CLEO
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:1 (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 doubly Cabibbo-suppressed D0→K+π- and Cabibbo-favored D̄0→K+π-. We analyze a sample of 1.0×106 D0D̄0 pairs from 281pb-1 of e+e- collision data collected with the CLEO-c detector at Ecm=3.77GeV. By combining CLEO-c measurements with branching fraction input and time-integrated measurements of RM≡(x2+y2)/2 and RWS≡Γ(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. In addition, by further including external measurements of charm mixing parameters, 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.Search for new heavy particles decaying to Z0Z0→eeee in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:1 (2008)
Abstract:
We report the results of a search for the anomalous production of a massive particle decaying to four electrons via two Z0 bosons in 1.1fb-1 of pp̄ collisions at s=1.96TeV collected by the CDF II detector at Fermilab. We employ optimized electron identification criteria to maximize acceptance and efficiency. We estimate the backgrounds in the invariant mass range 500-1000GeV/c2 to be 0.028±0.009(stat)±0.011(syst) events. We observe zero events in this search region. Assuming a Randall-Sundrum graviton production model, we set 95% C.L. limits on σ×BF(G→Z0Z0)<4- 6pb, depending on the graviton mass. © 2008 The American Physical Society.Branching fractions for transitions of ψ(2S) to J/ψ
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:1 (2008)
Abstract:
We report determination of branching fractions for the decays ψ(2S)→h+J/ψ, where h=any, π+π-, π0π0, η, π0, and γγ through χc0,1,2. These measurements use 27M ψ(2S) decays produced in e+e- collision data collected with the CLEO detector. The resulting branching fractions and ratios thereof improve upon previously achieved precision in all cases, and in combination with other measurements permit determination of B(χcJ→γJ/ψ) and B(ψ(2S)→light hadrons). © 2008 The American Physical Society.Model-independent and quasi-model-independent search for new physics at CDF
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:1 (2008)
Abstract:
Data collected in run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over 300 exclusive final states in 927pb-1 of pp̄ collisions at s=1.96TeV reveals no such significant indication of physics beyond the standard model. © 2008 The American Physical Society.Search for resonant tt[overline] production in pp[overline] collisions at sqrt[s]=1.96 TeV.
Phys Rev Lett 100:23 (2008) 231801