120540241
Tests of cesium iodide crystals for an electromagnetic calorimeter
Abstract A new electromagnetic shower detector will be constructed for the CLEO II experiment at CESR. It will consist of 8000 CsI(Tl) crystals coupled to solid state photodiodes. Extensive tests on the response of 175 CsI crystals are reported here. Each block measured 5 cm by 5 cm in cross section and 30 cm (16.2 radiation lengths) in depth. A fast and reliable method to determine acceptable light output and uniformity of crystals using a 137 Cs radioactive source and photomultiplier readout was successfully developed. For test beam studies each crystal was equipped with four silicon photodiodes connected to a low-noise charge amplifier. Calibration with a positron test beam yielded average light output of 2500 photoelectrons per MeV and showed good correlation with the radioactive source exposures. In the beam tests at 180 (5000) MeV, energy resolutions of 4% (1.5%) and position resolutions transverse to the beam of 1.2 (0.3) cm were achieved. The effects of material between and in front of crystals, non-normal incidence, and staggering of adjacent crystals were studied, and together were found to degrade the energy resolution by only a modest amount. Operation of the system near room temperature will ensure low noise and stable response. The radiation sensitivity of a number of CsI blocks was measured and found to be acceptable for the radiation levels anticipated in CLEO II.
6960296
Future of Heavy Flavour Physics: Experimental Perspective
I discuss what measurements need to be done to search for physics beyond the Standard CKM model, rather than just what studies can be done in the near future. It is also important to accurately measure the CKM matrix elements. Current best estimates for two important elements are: jVcbj=0 :03810:0021 andjVub=Vcbj=0 :0850:019. Finally, future experiments are discussed.
118259341
Leptonic and Semileptonic Decays from CLEO‐c
The CLEO‐c measurement of the purely leptonic decay rate D+ → μ+v determines the value of the pseudoscalar decay constant fD+ = (222.6 ± 16.7−3.4+2.8) MeV, allowing for a precision test of strong interaction theories. Semileptonic decay branching ratios are also summarized.
122170479
Particle identification by ionization measurements: Description of the CLEO dEdx system
Abstract We describe the design, construction and performance of a pressurized proportional chamber system intended to identify particles by means of their energy loss in thin gas samples. The system is part of the CLEO detector at the Cornell Electron-Positron Storage Ring (CESR).
122354898
The discovery of the B mesons
In 1983 the CLEO collaboration first, fully reconstructed B meson decays. I describe here what was done and how these procedures have evolved.
125049924
A1 PRODUCTION IN CHARGE EXCHANGE REACTIONS
118451431
COMPTON SCATTERING FROM RELATIVISTIC ELECTRONS
108181646
ELECTRIC FIELD MEASUREMENTS IN THE MARK I ACCELERATOR BY THE GLO-BALL METHOD
210852321
MARK I MTA LINEAR ACCELERATOR RUN NO. 3
Experimental operation of Mark I from July 29 through Sept. 24, 1952 is reported. During the preceding two months shutdown, spark-damaged drift tubes No. 0, 1, and 2 were repaired and chemically cleaned. After a slow "bake-in" procedure, a cavity voltage of 20-Mv at 16% duty cycle was obtained. Although operation was not too steady, some preliminary beam evaluation tests were made. Proton acceleration threshold voltage was determined to be 18.5 Mv, based on the associated rapid increase in neutron flux beyond the D-8B target. The beam was found to be about 1 in. off from the cavity axis at the target. A pulsed beam current of 50 to 70 ma peak was reached. The results indicated that there was nothing to prevent a high-current pulsed beam from being produced. However, in spite of careful cleaning and slow bake-in methods, sparking in the 0-1 gap was still a problem. Since small scale tests indicated that Inconel had better resistance to spark damage than the deoxidized highphosphorous Cu originally used, Mark I was shut down to install Inconel overlays on the first two drift tubes. (For preceding report in series see LRL-71.) (auth)
117517443
A FORM-FREE, SEMIPHENOMENOLOGICAL, ERROR-BOUNDED, POTENTIAL REPRESENTATION OF TWO-NUCLEON EXPERIMENTS.