G. Majumder

First measurement of Γ(D* +) and precision measurement of m D*+-m D0

We present the first measurement of the D*+ width using 9/fb of e+ e- data collected near the Upsilon(4S) resonance by the CLEO II.V detector. Our method uses advanced tracking techniques and a reconstruction method that takes advantage of the small vertical size of the CESR beam spot to measure the energy release distribution from the D*+ -> D0 pi+ decay. We find Gamma(D*+) = 96 +- 4 (Statistical) +- 22 (Systematic) keV. We also measure the energy release in the decay and compute Delta m = m(D*+) - m(D0) = 145.412 +- 0.002 (Statistical) +- 0.012 (Systematic) MeV/c^2

Construction, pattern recognition and performance of the CLEO III LiF-TEA RICH detector

We briefly describe the construction and performance of the LiF-TEA RICH detector constructed for the CLEO III experiment.

THE CLEO RICH DETECTOR

Abstract We describe the design, construction and performance of a Ring Imaging Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones with a novel “sawtooth”-shaped exit surface. Photons in the wavelength interval 135–165xa0nm are detected using multi-wire chambers filled with a mixture of methane gas and triethylamine vapor. Excellent π / K separation is demonstrated.

Performance of the CLEO III LiF-TEA ring imaging Cherenkov detector in a high-energy muon beam

Abstract The CLEO III Ring Imaging Cherenkov detector uses LiF radiators to generate Cherenkov photons which are then detected by proportional wire chambers using a mixture of CH 4 and TEA gases. The first two photon detector modules which were constructed, were taken to the Fermilab and tested in a beam dump that provided high-momentum muons. We report on results using both plane and “sawtooth”–shaped radiators. Specifically, we discuss the number of photoelectrons observed per ring and the angular resolution. The particle separation ability is shown to be sufficient for the physics of CLEO III.

The CLEO-III ring imaging Cherenkov detector

Abstract The CLEO detector has been upgraded to include a state of the art particle identification system, based on the Ring Imaging Cherenkov detector (RICH) technology, in order to take data at the upgraded CESR electron positron collider. The expected performance as well as the preliminary results are reviewed from an engineering run during the first few months of operation of the CLEO III detector.

First observation of B̄ 0→ D* 0π +π +π -π -decays

We report on the observation of B0bar -> D*0 pi+ pi+ pi- pi- decays. The branching ratio is (0.30 +/- 0.07 +/- 0.06)%. Interest in this particular mode was sparked by Ligeti, Luke and Wise who propose it as a way to check the validity of factorization tests in B0bar -> D*+ pi+ pi- pi- pi0 decays.

Search for the Decay B(bar sign){sup 0}{yields} D{sup *0}{gamma}

We report results of a search for the rare radiative decay B0 ->D*0 gamma. Using 9.7 million BB meson pairs collected with the CLEO detector at the Cornell Electron Storage Ring, we limit Br(B0->D*0 gamma)<5.0 * 10^-5 at 90% CL. This provides evidence that anomalous enhancement is absent in W-exchange processes and that weak radiative B decays are dominated by the short-distance b ->s gamma mechanism in the Standard Model.