123664987
Calibration and performance of a drift chamber spectrometer
Abstract We describe the calibration of a forward, high-resolution, drift chamber spectrometer used in a series of high energy experiments at Fermilab. We discuss the position-time calibration, the overall performance, and the spatial resolution, obtained under data-taking conditions for two kinds of field-shaping wire geometries.
121484834
Avoidance of counter-example to non-abelian Bloch-Nordsieck conjecture by using coherent state approach
It is shown that the counter-example to the non-abelian Bloch-Nordsieck conjecture in “q + q → γ∗ + soft gluons” to order αs2 is avoided at the cross section level if the initial st prepared according to the coherent state approach for treatment of the infrared region of non-abelian gauge theories.
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.
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.
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.
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>>
115882781
Cheng-wu picture applied to gamma p ---> rho0 p and phi p
119987004
Rishon model of quarks and leptons with double SU(2) symmetry and Dirac magnetic moments
Abstract Two-doublet rishon models are proposed to avoid some of the kinematic and dynamic difficulties of the single-doublet rishon model. One has point-like magnetic moments only for leptons. The other, based on an anti-pairing hypothesis, has point-like leptons and quarks.
120421012
The psion family: Relativistic charmonium
The authors have reported earlier that the spectrum of the psion family suggests a treatment based on an O(4) harmonic-oscillator family with O(4) quantum number M = 0 (equally spaced, mass-squared linear Regge trajectories). This results in the new J/subP//subC/ quantum numbers: 0$sup ++$ for 2.8 GeV/ c$sup 2$; 2$sup ++$, 1$sup -+$, 0$sup ++$ for the 3.4-GeV/c$sup 2$ mass region. All radiative decays are related through a single O(4) coupling S/sub mu//sub nu/ F/sub mu//sub nu/, where S/sub mu//sub nu/ is the internal-space angular-momentum operator. The details of the calculations of radiative transition widths and of the $gamma$$gamma$ angular correlation functions are given. Experimental signatures are discussed and compared with the nonrelativistic charmonium scheme; among others J $Yields$ O (2.8) + $gamma$ and psi ' $Yields$ O (2.8) + $gamma$ are small, being forbidden in the strict O(4) limit. O (2.8) is expected to be narrow like all other psions below the 4.0-GeV/c$sup 2$ region. chi$sub 0$(3.41) and chi$sub 1$(3.49) total widths are expected to be around 630 keV and 185 keV respectively. The missing decays of psi ' could be due to psi ' $Yields$ O + $omega$ ( approx. 32%). (AIP)
122358666
Production thresholds for quark and for diquark pairs in ee-bar annihilation as tests of charm, then color, excitation
We have pointed out earlier that the decrease at high energies in the ratio of charged-particle energy to total energy in ee-bar annihilation into hadrons and the rise in R in the 4-GeV region suggest first charm, then color, excitation. We present here an analysis of the pair-production thresholds for quarks (responsible for ..mu..e events) and for diquarks (threshold near 4.3 GeV) based on the simple mass spectrum generated by the popular color-octet vector-meson-exchange mechanism, but here in the context of R data and the integrally charged three-quartet model. Our emphasis throughout is a phenomenological one, with special attention to experimental signatures in annihilation and lepton-pair production which can exclude this economical model. For this spectrum we find there must exist a new color-symmetry-violating coupling responsible for the decays of quarks. From the identification of the U particles as quarks, it is suggested that this includes a weak interaction mediated by colored, right-handed quark-neutrino currents coupled to the usual charged currents.
118047130
Absence of strangeness-changing, neutral current effects from the symmetric quark model