Charmed-strange Mesons Research Articles

Measurement of the decay D* s2 + (2573) → D0K+

Using the ARGUS detector at the e+e− storage ring DORIS II at DESY we have measured the parameters of a charmed strange meson D* s2 + (2573) decaying into D0K+. The mass of this state was found to be (2574.5±3.3±1.6) MeV/c 2. The measured value of its width is (10.4±8.3±3.0) MeV and the product of the production cross section and branching ratio for this channel was determined to be (10.6±4.2 −1.2 +2.3 ) pb.

Observation of a new charmed-strange meson

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*+K0. Its mass is observed to be 2535.9±0.6±2.0 MeV/c2 and its width to be less than 4.6 MeV/c2 at the 90% confidence level. No structure is observed at this mass in the D+K0 invariant mass spectrum, which suggests that an unnatural spin-parity is preferred.

Measurement of the Ds+ lifetime.

We have observed 99 decays of the charmed strange meson, the D/sub s//sup +/ (formerly called the F/sup +/), into the phi..pi../sup +/ (61) and antiK*/sup 0/K/sup +/ (38) final states in the Fermilab photoproduction experiment E-691. We determine the lifetime to be (.48/sub -.05//sup +.06/ +- .02) x 10/sup -12/s, Using our reported measurement of the D/sup 0/ lifetime, we calculate the ratio tau(D/sub s//sup +/)/tau(D/sup 0/) = (1.10 +- .15 +- .04).