R. Culbertson

First evidence of

Abstract We report evidence of a narrow resonance at a mass of 2705.9 ± 3.3 ± 2.0 MeV/c2 in the final state Ω−π+ and the charge conjugate. The mass and width support the interpretation of a weakly decaying doubly strange charmed baryon, the Ω c 0 . Limits on the relative branching ratios for Ω c 0 →Ω − K − π + π + and Ω c 0 →Ω − π − π + π + are also presented.

Analysis of the decay mode D+ ---> anti-K*0 mu+ neutrino

Abstract Fermilab high-energy photoproduction experiment E687 provides a high statistics sample of the decay mode D + → K ∗0 μ + ν (charge conjugates are implied). Our analysis yields a branching ratio of Γ (D + → K ∗0 μ + ν) Γ (D + → K − π + π + ) = 0.56±0.04±0.06 . The ratios of the form factors governing the decay are measured to be R ν = 1.74 ±0.27±0.28 and R 2 = 0.78±0.18±0.10, implying a polarization of Γ l Γ t = 1.20±0.13 ±0.13 for the electron decay. Finally, we report new limits on the decay modes D + → K − π + μ + ν (nonresonent) and D + → K ∗0 π 0 μ + ν .

Measurement of the lifetime of the Xi c0.

A measurement of the lifetime of the charmed strange baryon [Xi][sub [ital c]][sup 0] is presented. The data were accumulated by the Fermilab high energy photoproduction experiment E687. The measurement has been made using 42[plus minus]10 [Xi][sub [ital c]][sup 0][r arrow][Xi][sup [minus]][pi][sup +] decays. The lifetime of the [Xi][sub [ital c]][sup 0] is measured to be 0.101[sub [minus]0.017][sup +0.025][plus minus]0.005 ps and its mass is measured to be 2462.1[plus minus]3.1[plus minus]1.4 MeV/[ital c][sup 2].

Analysis of the Cabibbo suppressed decay D0 → π−l+ν

Abstract Results for the Cabibbo suppressed semileptonic decays D 0 → π − e + ν and D 0 → π − μ + ν (charge conjugates are implied) are reported by Fermilab photoproduction experiment E687. We find 45.4 ± 13.3 events in the electron mode and 45.6 ± 11.8 in the muon mode. The relative branching ratio BR (D 0 →π − l + v) BR (D 0 →K − l + v) for the combined sample is measured to be 0.101 ± 0.020 (stat.) ± 0.003 (syst.) 14 .

A Precise measurement of the D(S)+- meson lifetime

A precise measurement of the D s ± meson lifetime is reported. The data were accumulated by the high energy photoproduction experiment E687 at Fermilab in the 1990-1991 fixed target run. The measurement has been done using 900 fully reconstructed D s ± →Oπ ± decays. The lifetime of the D s ± meson is measured to be 0.475±0.020±0.007 psA precise measurement of the [ital D][sub [ital s]][sup [plus minus]] meson lifetime is reported. The data were accumulated by the high energy photoproduction experiment E687 at Fermilab in the 1990--1991 fixed target run. The measurement has been done using 900 fully reconstructed [ital D][sub [ital s]][sup [plus minus]][r arrow][phi][pi][sup [plus minus]] decays. The lifetime of the [ital D][sub [ital s]][sup [plus minus]] meson is measured to be 0.475[plus minus]0.020[plus minus]0.007 ps.

Observation of the vector meson Cabibbo suppressed decay D+ → ρ0π+ν

Abstract We report on the first statistically significant observation of the vector meson Cabibbo suppressed semileptonic decay D+ → ρ0μ+ν. We measure the branching ratio of the decay mode D+ → ρ0μ+ν (plus possible unobserved γ from D+ → η′μ+ν, η′ → γρ0) with respect to the decay mode D + → K ∗0 μ + ν to be BR (D + → ρ 0 μ + ν) BR (D + → K ∗0 μ + ν) = 0.079 ± 0.019 ( stat ) ± 0.013 ( syst ) . Data were collected by Fermilab photoproduction experiment E687.

Branching ratios of the decays D0 ---> anti-K0 K0 and D0 ---> K0(s) K0(s) K0(s)

Abstract The branching ratios of D 0 → K 0 K 0 and D0 → Ks0Ks0Ks0 relative to D 0 → K 0 π + π − are reported. The data were accumulated in the 1990–1991 fixed target running period of the Fermilab high energy photoproduction experiment E687. Γ (D 0 → K 0 K 0 )/Γ (D 0 → K 0 π + π − is measured to be 0.039±0.013±0.013 and Γ (D 0 →K s 0 K s 0 K s 0 )/Γ (D 0 → K 0 π + π − ) is measured to be 0.035±0.012±0.006. We also measure Γ (D 0 → K 0 π + π − /Γ (D 0 → K − π + ) to be 1.61±0.10±0.15.

Observation and mass measurement of omega(c)0 ---> sigma+ k- k- pi+

Abstract We present evidence for the Ω c 0 in a new decay mode Ω c 0 → Σ + K − K − π + , for which we find 42.5 ± 8.8 events with a mass of 2699.9 ± 1.5 ± 2.5 MeV/c 2 . The data are from Fermilab high energy photoproduction experiment E687.

Observation and mass measurement of

Abstract We present evidence for the Ω c 0 in a new decay mode Ω c 0 → Σ + K − K − π + , for which we find 42.5 ± 8.8 events with a mass of 2699.9 ± 1.5 ± 2.5 MeV/c 2 . The data are from Fermilab high energy photoproduction experiment E687.

Precise measurement of theDs±meson lifetime

A precise measurement of the D s ± meson lifetime is reported. The data were accumulated by the high energy photoproduction experiment E687 at Fermilab in the 1990-1991 fixed target run. The measurement has been done using 900 fully reconstructed D s ± →Oπ ± decays. The lifetime of the D s ± meson is measured to be 0.475±0.020±0.007 psA precise measurement of the [ital D][sub [ital s]][sup [plus minus]] meson lifetime is reported. The data were accumulated by the high energy photoproduction experiment E687 at Fermilab in the 1990--1991 fixed target run. The measurement has been done using 900 fully reconstructed [ital D][sub [ital s]][sup [plus minus]][r arrow][phi][pi][sup [plus minus]] decays. The lifetime of the [ital D][sub [ital s]][sup [plus minus]] meson is measured to be 0.475[plus minus]0.020[plus minus]0.007 ps.