OPMD

Abstract:

This article describes improved measurements by CLEO of the B⁰→Ds⁺D*^- and B⁰→Ds*⁺D*^- branching fractions, and first evidence for the decay B⁺→Ds(*)⁺D̄** ⁰, where D̄**⁰ represents the sum of the D̄1(2420)⁰, D̄2*(2460)⁰, and D̄1(j = 1/2)⁰ L = 1 charm meson states. Also reported is the first measurement of the Ds*⁺ polarization in the decay B⁰→Ds*⁺D*^-. A partial reconstruction technique, employing only the fully reconstructed Ds⁺ and slow pion πs^- from the D*^-→D̄⁰πs^- decay, enhances sensitivity. The observed branching fractions are B(B⁰→Ds⁺D*^-) = (1.10±0.18±0.10±0.28)%, B(B⁰→Ds*⁺D*^-) = (1.82±0.37±0.24 ±0.46)% , and B(B⁺→Ds(*) ⁺D̄**⁰) = (2.73±0.78±0.48±0.68)%, where the first error is statistical, the second systematic, and the third is the uncertainty in the Ds⁺→φπ⁺ branching fraction. The measured Ds*⁺ longitudinal polarization, ΓL/Γ = (50.6±13.9±3.6)%, is consistent with the factorization prediction of 54%.

Abstract:

This paper reports an updated measurement of the standard model CP violation parameter sin 2β using the CDF Detector at Fermilab. The entire run I data sample of 110 pb -1 of proton-antiproton collisions at √s = 1.8 TeV is used to identify a signal sample of ∼400 B→J/φK s0 events, where J/φ→μ + μ - →μ + μ - . The flavor of the neutral B meson is identified at the time of production by combining information from three tagging algorithms: a same-side tag, a jet-charge tag, and a soft-lepton tag. A maximum likelihood fitting method is used to determine sin 2β=0.79 -0.44+0.41 (stat+syst). This value of sin 2β is consistent with the standard model prediction, based upon existing measurements, of a large positive CP-violating asymmetry in this decay mode. ©2000 The American Physical Society.

Abstract:

The resonant structure of the four pion final state in the decay τ→3 ππ 0 ν τ has been analyzed using 4.27 million τ + τ - pairs collected by the CLEO II experiment at the Cornell Electron Storage Ring. A partial wave analysis of the resonant structure of the τ→3 ππ 0 ν τ decay has been performed; the spectral decomposition of the four pion system is dominated by the ωπ and a 1 π final states. The mass and width of the ρ′ resonance have been extracted from a fit to the τ→ωπν τ spectral function. We have searched for second class currents in the decay τ→ωπν τ using spin-parity analysis and established an upper limit on the non-vector current contribution. © 2000 The American Physical Society.

Abstract:

A full angular analysis of both the B0 and Bs0 decay modes was carried out. For this analysis, the B0 → J/ψK*0 and Bs0 → J/ψφ decays were reconstructed. The obtained data were analyzed in detail.

Abstract:

Dijet production by double Pomeron exchange (DPE) in p̄p collisions at √ s = 1800 GeV was performed. Factorization was tested by comparing the diffractive structure function measured in single diffractive (SD) with that determined from DPE. As a result, a class of events with a double Pomeron exchange topology were observed.