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J. Libby

Publications and source records attributed to J. Libby.

239 records · Page 14Linked to original sources
arXiv2010

Measurement of the eta_b(1S) mass and the branching fraction for Upsilon(3S) --> gamma eta_b(1S)

We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming Gamma(eta_b) = 10 MeV/c^2, we obtain B(Upsilon(3S) --> gamma eta_b) = (7.1 +- 1.8 +- 1.1) X 10^{-4}, where the first error is statistical and the second is systematic. The statistical significance is about 4 sigma. The mass is determined to be M(eta_b) = 9391.8 +- 6.6 +- 2.0 MeV/c^2, which corresponds to the hyperfine splitting Delta M_{hf}(1S)_b = 68.5 +- 6.6 +- 2.0 MeV/c^2. Using 9 million Upsilon(2S) decays, we place an upper limit on the corresponding Y(2S) decay, B(Y(2S) --> gamma eta_b) < 8.4 X 10^{-4} at 90 % confidence level.

hep-ex↗
arXiv2009

Inclusive Radiative psi(2S) Decays

Using e+e- collision data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decay psi(2S)->gamma+gluon+gluon. We determine the ratio R of that inclusive direct photon decay rate to that of the three-gluon decay rate psi(2S)->3-gluon to be R(z>0.4)=0.070+/-0.002+/-0.019+/-0.011, with z defined as the scaled photon energy relative to the beam energy. The errors shown are statistical, systematic, and that due to the uncertainty in the input branching fractions used to extract the ratio, respectively. This R value is approximately 2/3 of the comparable value for the J/psi(1S), both in the region z>0.4, and also when extrapolated to the full range z>0.

hep-ex↗
arXiv2008

Measurement of the eta'-meson mass using J/psi--> gamma eta'

We measure the mass of the eta' meson using psi(2S)--> pi+ pi- J/psi, J/psi--> gamma eta' events acquired with the CLEO-c detector operating at the CESR e+e- collider. Using three decay modes, eta'--> rho0 gamma, eta'--> pi+ pi- eta with eta--> gamma gamma, and eta'--> pi+ pi- eta with eta--> pi+ pi- pi0, we find M(eta') = 957.793 +- 0.054 +- 0.036 MeV, in which the first uncertainty is statistical and the second is systematic. This result is consistent with but substantially more precise than the current world average.

hep-ex↗
arXiv2005

The Discovery Potential of a Super B Factory

The Proceedings of the 2003 SLAC Workshops on flavor physics with a high luminosity asymmetric e+e- collider. The sensitivity of flavor physics to physics beyond the Standard Model is addressed in detail, in the context of the improvement of experimental measurements and theoretical calculations.

hep-ph↗