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 thee+e− storage ring DORIS II, we have investigated inclusive momentum spectra of charged pions, kaons, and protons from decays of the υ(4S) meson. The kaon spectra have been measured in two independent ways, by coherently exploiting the detector's particle identification capabilities, and by detecting decays in-flight. The extracted mean multiplicities for charged hadrons are 7.17±0.05±0.14 pions, 1.56±0.03±0.05 kaons and 0.110±0.010±0.007 protons per υ(4S) decay, where pions and protons fromKso and Δ decays have been subtracted.
Inclusive pion spectrum from UPSI(4S) decays.
Inclusive pion spectrum from UPSI(4S) decays with KS and LAMBDA decay particles included.
Inclusive kaon spectrum from UPSI(4S) decays.
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.
The production ofDS+ mesons inB meson decays, and inq\(\bar q\) continuum events, has been studied with the ARGUS detector at thee+e− storage ring DORIS II. In addition to the measurement of inclusiveDS+ production in γ(4S)→B\(\bar B\) decays, all eight two-body decay modesB→DS(*)D(*) have been measured with branching ratios between 1% and 3%. By comparing our inclusive and exclusive results to predictions of heavy quark effective theory, a value of (267±28) MeV × [2.7%/BR(Ds+→φπ+)]1/2 is obtained for the weak decay constant fDS(*), averaged overDS+ andDS*+ mesons.
Inclusive D/S cross sections in continuum near to UPSI(4S).
We have measured theR value in non-resonante+e− annihilation using the ARGUS detector at the storage ring DORIS II. At a centre-of-mass energy\(\sqrt s= 9.36\) GeV the ratio of the hadronic cross-section to the μ-pair cross section in lowest order QED has been determined to beR=3.46±0.03±0.13. In addition, we have measured the charged-particle multiplicities in non-resonant hadron production at\(\sqrt s= 10.47\) GeV just below theB\(\bar B\) threshold and in ϒ (4S) resonance decays. For the average charged-particle multiplicities in continuum events and ϒ(4S)→B\(\bar B\) decays we obtain
Corrected for radiative effects and acceptance.
Unfolded charged particle multiplicity distribution for continuum events.
Unfolded charged particle multiplicity distribution for UPSILON(4S) events.
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 thee+e− storage ring DORIS II at DESY, we have measured the inclusive production ofD0,D+ andD*(2010)+ mesons inB decays and in nonresonante+e− annihilation around 10.6 GeV. The inclusive branching ratios forB decays toD0,D+ andD*+ mesons are found to be (52.2±8.2±3.5)%, (27.2±6.3±3.5)% and (34.8±6.0±3.5)% respectively. Thus,D0 andD+ production account for about 70% of the charm produced inB decays, neglectingb→u contributions to the total width. The production cross sections and momentum spectra for continuume+e− annihilation are also presented.
Non-resonant inclusive cross sections.
Non-resonant inclusive cross sections.
Non-resonant inclusive cross sections.
A spin-parity analysis of the ϱ + ϱ − system in the reaction γγ→ϱ + ϱ − →Π + Π − Π 0 Π 0 has been performed using the ARGUS detector at the e + e − storage ring DORIS II at DESY. The cross section is found to be dominated by the amplitudes J P = 0 + and J P = 2 + ( J z = 2).
No description provided.
Cross section for different JP states.
Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have observed production of the charmed-strange baryon Ξ c + and its neutral isospin partner, the Ξ c 0 . The Ξ c + was reconstructed in the final state Ξ − π + π + , while the Ξ c 0 was seen in decay to Ξ − π + and Ξ − π + π + π − . The average Ξ c fragmentation spectrum has been determined, as well as the production cross section times branching ratio for each decay mode. The charged and neutral masses were measured to be 2465.1 ± 3.6 ± 1.9 MeV/ c 2 and 2472.1 ± 2.7 ± 1.6 MeV/ c 2 respectively, corresponding to a mass-splitting, M ( Ξ c + ) − M ( Ξ c 0 ), of −7.0±4.5±2.2 MeV/ c 2 .
Cross sections times branching ratios for $\Xi_c^0$ and $\Xi_c^+$ production at $E_{\mathrm{cms}} = 10.5$ GeV and $x_p > 0.5$.
Cross sections times branching ratios for $\Xi_c^0$ and $\Xi_c^+$ production at $E_{\mathrm{cms}} = 10.5$ GeV and all $x_p$.
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