Observation of the semileptonic decay of the charmed baryon in the decay channel has been made using the ARGUS detector at the e + e − storage ring DORIS II at DESY. The cross section times branching ratio was found to be .
No description provided.
No description provided.
Averaging the above two results.
Using the detector ARGUS at the storage ring DORIS II of DESY, we have found evidence for the production of the charmed and doubly strange baryon Ω c through its decay channel Ξ − K − π + π + . Its mass has been determined to be ((2719.0±7.0±2.5)MeV/ c 2 , and the product of production cross section and branching ratio the above channel to be (2.41±0.90±0.30) pb.
No description provided.
Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have observed parity violation in the decay Λ ± c → Λπ ± . We measure the coefficient of parity violation, α Λ c , to be −0.96±0.42. In addition, we measure σ BR ( Λ + c → Λπ + and σ BR ( Λ + c → Σ 0 π + ) to be, respectively, (2.2±0.3±0.4) pb and (2.0±0.7±0.4) pb.
No description provided.
Direct observations of the semileptonic decay of Λ c + in the decay channels Λ c + → Λ e + X and Λ c + → Λμ + X have been made using the ARGUS detector at the DORIS II e + e − storage ring. The cross section times branching ratio were found to be σ (e + e − → Λ c + X)·BR( Λ c + → Λ e + X)=4.20±1.28±0.71 pb and σ (e + e − → Λ c + X)·BR( Λ c + → Λμ + X)=3.91±2.02±0.90 pb.
No description provided.
Using the ARGUS detector at the DORIS II e + e - storage ring at DESY, we have observed a new charmed meson of mass (2469±4±6) MeV/ c 2 , decaying to D 0 π + . This state is a strong candidate for the charged isospin partner of the D ∗ (2459) 0 . The isospin mass splitting is measured to be (14±5±8) MeV / c 2 .
The cross section times branching ratio.
Using the ARGUS detector at the DORIS II e + e − storage ring at DESY, we have obtained evidence for a new charmed-strange meson which decays into D *+ K 0 . Its mass is observed to be 2535.9±0.6±2.0 MeV/ c 2 and its width to be less than 4.6 MeV/ c 2 at the 90% confidence level. No structure is observed at this mass in the D + K 0 invariant mass spectrum, which suggests that an unnatural spin-parity is preferred.
No description provided.
Using data collected with the ARGUS detector, we have performed a decay angular analysis of the enhancement, previously known as the D ∗ (2420), seen in the final state D ∗ (2010) + π − . We thereby exhibit that the observed broad structure is actually due to two relatively narrow resonances, one of which is identified as the D ∗ (2459) 0 , while the massof the other is measured to be (2414±2±5) MeV/ c 2 . The results of the analysis are in good agreement with the interpretation of the two states as L =1 D mesons of spin-parities 2 + and 1 + respectively.
The cross sections times branching ratio.
It is assumed that decays D PION and D* PION saturate the total widths.
Using the ARGUS detector at thee+e− storage ring DORIS II, flavour-dependent kaon production inB meson decays has been studied. Using the leptons as flavour tags, it has been possible to separately measure the multiplicities ofK+,K− andKs0 in inclusiveB decays and in semileptonicB decays. The kaon production in semileptonicB decays was further used to estimate the ratio of charmed decays over all decays, and thus also the fraction of charmlessB decays.
B mesons are produced in the reaction E+ E- --> B BBAR at sqrt(s) = 10.6 GeV.
Using the ARGUS detector at the e + e - storage ring DORIS II at DESY, we have observed the decay D s + → η'π + in two decay modes of the η'. We measure the ratio of branching ratios BR(D s + → η'π + )/BR(D s + → Øπ + ) to be 2.5±0.5±0.3.
The cross section times Br(D/S+ --> ETAPRIME PI+), but is not included the ETAPRIME branching ratio.
We report a measurement of the production of antideuterons d in e + e − annihilation at centre-of-mass energies around 10 GeV using the ARGUS detector at the DORIS II storage ring. We observe an enhancement of d production in direct hadronic ϒ (1S) and ϒ (2S) resonance decays. From 21 events width a d candidate the inclusive cross section 1 σ dir had · d σ d p and the production rate of antideuterons are determined. A production rate of (6.0±2.0±0.6) × 10 -5 d per direct hadronic ϒ decay and a 90% CL upper limit of 1.7 × 10 −5 d per e + e − →q q continuum event are obtained. These results are related to antiproton production through a simple model.
Acceptance corrected, background subtracted momentum spectrum observed in UPSI(1S) and UPSI(2S) resonance decays.
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