G. Mageras

Inclusive K0 production in e+ e− annihilation at the upsilon resonances

We report on inclusive K0 production in the region of the upsilon resonances (9.4–10.6 GeV). The K0 yield for the resonances and continuum below the BB threshold is found to be constant at 0.82 ± 0.10 K0 per observed hadronic event. At the ϒ(4S), however, the K0 yield is significantly higher, 1.58 ± 0.35. This increase in K0 production and the differential cross section dσ/dp of kaons are consistent with BB decay of the ϒ(4S) resonance with the bottom quarks subsequently decaying primarily into charmed quarks.

Thrust distribution and decays of the ϒ bound states

Abstract We have studied the topologies of hadronic events in e + e - annihilation data taken in the region of the upsilon resonances with the non-magnetic CUSB detectors at CESR. Using a thrust-like variable we compare the decay of ϒ, ϒ′ and ϒPrime; find for ϒ″ a significant excess of high thrust events, which we interpret as evidence for electric dipole transitions.

Observation of ππ cascade decays of the ϒ

Abstract Using the CUSB detector at CESR, we have observed hadronic cascade decays ϒ ″ → ( ϒ or ϒ ′) + ( π + π − or π 0 π 0 ), where ϒ ( ϒ ′) → ( e + e − or μ + μ − ). We derive branching fractions of ϒ ″ → ϒ ′ π + π − . The dipion mass spectrum from ϒ ″ → ϒπ + π − shows no preference for high masses, in strong contrast to the decays ϒ ″ → ϒππ and ψ″ → J ψππ .