Measurement of the Λc + lifetime
Physical Review Letters 86:11 (2001) 2232-2236
Abstract:
The lifetime of the lowest-mass charm bryon is measured to provide a window for the nonperturbative sector of heavy quark decay. The data are obtained in a colliding beam environment in the CLEO II.V detector at the Cornell Electron Storage Ring. In this environment, the event topologies and backgrounds are very different from those encountered in high energy fixed-target experiments.First observation of the sigma(*+)(c) baryon and a new measurement of the sigma(*+)(c) mass.
Phys Rev Lett 86:7 (2001) 1167-1170
Abstract:
Using data recorded with the CLEO II and CLEO II.V detector configurations at the Cornell Electron Storage Rings, we report the first observation and mass measurement of the Sigma(*+)(c) charmed baryon, and an updated measurement of the mass of the Sigma(+)(c) baryon. We find M(Sigma(*+)(c))-M(Lambda(+)(c)) = (231.0+/-1.1+/-2.0) MeV, and M(Sigma(+)(c))-M(Lambda(+)(c)) = (166.4+/-0.2+/-0.3) MeV, where the errors are statistical and systematic, respectively.Study ofχ c 1 andχ c 2 meson production inBmeson decays
Physical Review D American Physical Society (APS) 63:3 (2001) 031102
Correlated a c + a c - production in e + e - annihilations at √s-10.5 GeV
Physical Review D 63:11 (2001)
Abstract:
Using 13.6 fb -1 of continuum two-jet e + e - →cc events collected with the CLEO detector, we have searched for baryon number correlations at the primary quark level. We have measured the likelihood for a A c+ charmed baryon to be produced in the hemisphere opposite a A c- relative to the likelihood for a A c- charmed baryon to be produced opposite an anticharmed meson D; in all cases, the reconstructed hadrons must have momentum greater than 2.3 GeV/c. We find that, given a A c- (reconstructed in five different decay modes), a Ac+ is observed in the opposite hemisphere (0.72±0.11)% of the time (not corrected for efficiency). By contrast, given a D in one hemisphere, a A c+ is observed in the opposite hemisphere only (0.21 ±0.02)% of the time. Normalized to the total number of either A c- or D "tags," it is therefore 3.52±0.45±0.42 times more likely to find a A c+ opposite a A~ than a D meson. This enhancement is not observed in the JETSET 7.3 e + e - →cc Monte Carlo simulation. ©2001 The American Physical Society.Search for the decay B+→D*+Ks 0
Physical Review D 64:7 (2001)