Measurement of Ds + and Ds *+ production in B meson decays and from continuum e+e- annihilation at √s = 10.6 GeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 65:9 (2002) 911041-911048
Abstract:
New measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̄ continuum events near the Y(4S) resonance are presented. Using 20.8 fb-1 of data on the Y(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B→Ds+ X)=(10.93±0.19±0.58±2.73)% and B(B→Ds*+X)=(7.9±0.8±0.7 ±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e- →Ds+X) × B(Ds+→φπ+)=7.55±0.20 ±0.34 pb and σ(e+e-→Ds *±X) × B(Ds+→φπ+) = 5.8±0.7±0.5 pb are measured at center-of-mass energies about 40 MeV below the Y(4S) mass. The branching fractions ΣB(B→Ds(*)+ D̄(*))=(5.07±0.14±0.30±1.27)% and ∑B(B→Ds*+D̄(*)) =(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1 ±0.3 MeV/c2 is also measured.Search for lepton-flavor violation in e+p collisions at DESY HERA
Physical Review D Particles Fields Gravitation and Cosmology 65:9 (2002) 920041-9200416
Abstract:
A search has been made for lepton-flavor-violating interactions of the type e+p→lX, where l denotes a μ or τ with high transverse momentum, at a center-of-mass energy √s of 300 GeV with an integrated luminosity of 47.7 pb-1 using the ZEUS detector at HERA. No evidence was found for lepton-flavor violation and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below √s, limits are set on λSearch for single-top-quark production in pp̄ collisions at √s=1.8 TeV
Physical Review D Particles Fields Gravitation and Cosmology 65:9 A (2002) 911021-911026
Abstract:
We search for standard model single-top-quark production in the W-gluon fusion and W* channels using 106 pb-1 of data from ppÌ„ collisions at √s=1.8 TeV collected with the Collider Detector at Fermilab. We set an upper limit at 95% confidence level (C.L.) on the combined W-gluon fusion and W* single-top cross section of 14 pb, roughly six times larger than the standard model prediction. Separate 95% C.L. upper limits in the W-gluon fusion and W* channels are also determined and are found to be 13 and 18 pb, respectively.51ÁÔÆæÈë¿Ú of B±→J/ψπ± and B±→J/ψ°Â± decays: Measurement of the ratio of branching fractions and search for direct CP-violating charge asymmetries
Physical Review D Particles Fields Gravitation and Cosmology 65:9 (2002) 911011-911017
Abstract:
We have studied the B±→J/ψπ± and B±→J/ψ°Â± decays using a 20.7 fb-1 data set collected with the BABAR detector. We observe a signal of 51±10 B±→J/ψπ± events and determine the ratio B(B± →J/ψπ±)/B(B±→J/ψ K±) to be [3.91±0.78(stat)±0.19(syst)]%. The CP-violating charge asymmetries for the B±→J/ψπ± and B±→J/ψ°Â± decays are determined to be AMeasurement of the photon-proton total cross section at a center-of-mass energy of 209 GeV at HERA
Nuclear Physics B 627:1-2 (2002) 3-28