Erratum: Measurement of particle production and inclusive differential cross sections in pp̄ collisions at √s=1.96TeV (Physical Review D - Particles, Fields, Gravitation and Cosmology)
Physical Review D - Particles, Fields, Gravitation and Cosmology 82:11 (2010)
Observation of single top quark production and measurement of
Physical Review D - Particles, Fields, Gravitation and Cosmology 82:11 (2010)
Abstract:
We report the observation of electroweak single top quark production in 3.2fb⊃-1 of pp̄ collision data collected by the Collider Detector at Fermilab at √s=1.96TeV. Candidate events in the W+jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3-0.5+0.6(stat+sys)pb, extract the value of the Cabibbo-Kobayashi-Maskawa matrix element |Vtb|=0.91-0.11+0. 11(stat+sys)±0.07(theory), and set a lower limit |Vtb|>0.71 at the 95%C.L., assuming mt=175GeV/c2.Measurements of branching fractions for electromagnetic transitions involving the $\chi_{bJ}(1P)$ states
(2010)
Search for rare and forbidden decays of charm and charmed-strange mesons to final states h±e e+
Physical Review D - Particles, Fields, Gravitation and Cosmology 82:9 (2010)
Abstract:
We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D+ and Ds+ mesons to final states of the form h±e e+, where h is either π or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818pb-1 at the center-of-mass energy E CM=3.774GeV containing 2.4×106 D+D- pairs and 602pb-1 at ECM=4.170GeV containing 0.6×106 Ds*±Ds pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D +→π+e+e-)<5. 9×10-6, B(D+→π-e +e+)<1.1×10-6, B(D+→ K+e+e-)<3.0×10-6, B(D +→K-e+e+)<3.5×10 -6, B(Ds+→π+e+e-)<2. 2×10-5, B(Ds+→π-e+e +)<1.8×10-5, B(Ds+→K+e +e-)<5.2×10-5, and B(Ds+→K -e+e+)<1.7×10-5. © 2010 The American Physical Society.Measurement of σ(pp→bb̄X) at √s=7 TeV in the forward region
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 694:3 (2010) 209-216