116758744
Pion dissociation in the nuclear Coulomb field
62166546
The design and PCB layout of the CDF Run 2 calorimetry readout module
The CDF Calorimetry Readout module, called the ADMEM, has been designed to contain both the analog circuitry which digitizes the phototube charge pulses and the digital logic which supports the readout of the results through the CDF Run 2 DAQ system. The ADMEM module is a 9U/spl times/400 mm VMEbus module, which is housed in a CDF VMEbus VIPA crate. The ADMEM must support near deadtimeless operation, with data being digitized and stored for possible readout every 132 ns or 7.6 MHz. This paper discusses the implementation of the analog and digital portions of the ADMEM module, and how the board was laid out to avoid the coupling of digital noise into the analog circuitry.
17434613
Proton irradiation effects on 2Gb flash memory
We report total ionizing dose and single event effects on 2 Gb Samsung flash memory devices after exposure to 200 MeV protons to various doses up to 83 krad(Si). We characterize observed failures and single event upsets on 22 devices from two different lots. Devices from both lots are robust to greater than 20 krad(Si) although we see evidence for lot-to-lot variation where only one lot appears robust up to about 50 krad(Si). Single event upsets are observed at a relatively low rate and are consistent with single isolated bit flips within registers that transfer bits to and from the flash memory cells.
44977344
The upgraded CDF front end electronics for calorimetry
The front-end electronics used in the calorimetry of the Collision Detector Facility (CDF) detector has been upgraded to meet system requirements for higher expected luminosity. A fast digitizer utilizing a 2- mu s, 16-b analog-to-digital converter (ADC) has been designed and built. Improvements to the front-end trigger circuitry have been implemented, including the production of 900 new front-end modules. Operational experience with the previous system is presented, with discussion of the problems and performance goals.<<ETX>>
122601142
SVX', the new CDF silicon vertex detector
Abstract The Collider Detector at Fermilab (CDF) radiation hardened silicon vertex detector (SVX') is described. The new detector has several improvements over its predecessor such as better signal to noise and higher efficiency. It is expected to have a radiation tolerance in excess of 1 Mrad. It has been taking data for several months and some preliminary results are shown.
120517617
Elastic Photoproduction of omega Mesons from Hydrogen, Deuterium, and Complex Nuclei
We have studied ..omega.. photoproduction using 7.5- to 10.5-GeV tagged photons. Cross sections from hydrogen lie 22% below the bubble chamber results of Ballam et al., but have a similar slope. Density matrices indicate approximate s-channel helicity conservation. The proton--neutron cross-section difference is midway between zero and the value suggested by the ..gamma..p--..gamma..n total-cross-section difference. Fits to the cross sections for D, Be, and Cu and those for Be, C, Al, Cu, and Pb from a previous experiment yield sigma/sub ..omega..N/ = 25.4 +- 2.7 mb and ..gamma../sub ..omega..//sup 2//4..pi.. = 7.6 +- 1.2. (AIP)
121781054
Relativistic dispersion analysis of R in the 4-GeV region
119943713
Non-Abelian structure of Yang-Mills theory and infrared-finite asymptotic states
The idea of Kulish and Faddeev for treating asymptotic dynamics is extended to derive a set of states with which the matrix element of quark scattering from a color-singlet external potential is shown to be free of the leading-order non-Abelian class of infrared divergences to fifth order in g.
119996715
Neutrino physics: New flavors or charm, then color, excitation
Investigation of charm, then color, excitation through right-handed, color-octet currents is suggested as a more economical way than adding new flavors for avoiding the conflict of the Weinberg-Salam model with present ..nu.. and nu-bar data. The effects from simply adding to the Glashow-Iliopoulos-Maiani current a new right-handed color-octet weak current (the analog of the usual Cabibbo current) are calculated and compared with available charged-current and neutral-current data. A color-octet piece in the weak currents, in general, does not change the lowest-order predictions for the Weinberg-Salam model for (i) elastic and quasi-elastic ..nu..- or nu-bar-nucleon scattering, (ii) neutral-current-induced parity-violating transitions in atomic physics, and (iii) coherent neutrino-nucleus scattering.
124235284
Infrared Properties of Unusual Initial State Interactions
The related roles of gauge invariance and of initial coherent/ degenerate states in the factorization of QCD processes into short-distance and long-distance parts are discussed. For ππ →μ+μ - + X it is shown that although the systematic summation over all possible spectator interactions removes the outside soft-IR divergences in the non- overlapping ladder Glauber diagrams, unphysical inside soft-IR divergences persist. So, the on-shell Glauber region is not a gauge invariant concept which can be physically isolated from radiative corrections which non-trivially involve other diagrammatic regions. It is conjectured that in QCD non-factorization is inconsistent with local gauge invariance.
122185625
Composite models of leptons