25979948
Control and data acquisition electronics for the CDF Silicon Vertex Detector
A control and data acquisition system has been designed for the CDF Silicon Vertex Detector (SVX) at Fermilab. The system controls the operation of the SVX Rev D integrated circuit (SVX IC) that is used to instrument a 46000 microstrip silicon detector. The Fastbus Sequencer, a programmable timing generator for controlling the SVX Rev D integrated circuit is described along with the controller and digitizer modules that reside in SVX Rabbit crates. A method for providing timing patterns to the wedge that allows pulsewidth control to within 10 ns over a period of 1 mu s is presented. Diagnostics abilities that provide mechanisms for understanding data and timing integrity are discussed.<<ETX>>
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.
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.
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.
202114504
Presence and Absence of Scaling Violations in Inclusive Leptoproduction
In the standard model, the heavy--quark-parton scaling variable is used to study the effects of the color-octet piece of the integrally-charged--quark-parton electromagnetic current which would violate scaling in deep-inelastic leptoproduction. With spin-1/2 partons it is found that sigma/sub L//sigma/sub T/ would deviate significantly from zero since (sigma/sub L//sigma/sub T/)/sub muN/ approx. = 4m/sub c//sup ts2/f/sub v/(z)/ 5Q/sup 2/f/sub v/(x), where f/sub v/(z) + u/sub v/(z) + d/sub v/(z), m/sub c//sup ts2/ = effective mass-squared of quark-parton in color-excited hadron, and z approx. = x + m/sub c//sup ts2//2MEy. Such scaling violations must occur in the ..mu.. data at currently available energies if the step of 2 units of R (beyond charm) in the 4-GeV region in the SPEAR data for ee-bar annihilation is due to a color threshold for the production of color-octet qq-bar mesons, qqq baryons, and/or quark-antiquark pairs. Consistency is shown between the scaling violations in the electroproduction data in the x < or = 0.2 region and the energy independence in the data of the CDHS collaboration for charged-current neutrino distributions for average y and for sigma/sup nu-bar/sigma/sup ..nu../. Exclusive final states responsible for electroproduction scaling violations in the x < or = 0.2 region would containmore » the tau-particle-antiparticle pairs (i.e., integrally charged quarks) and/or high-momentum photons (few GeV) from radiative decay modes of color-octet hadrons.« less
119847840
Linear Regge trajectories for the psion family and O(4) dynamics
The newly discovered psion family can be described by mass-squared linear Regge trajectories. The new J/subP//subC/ assignments are for 2.8 GeV/ c$sup 2$, 0$sup ++$, and for the 3.4 region, 2$sup ++$, 1$sup -+$, 0$sup ++$. All radiative decays are related through a single S/sub mu//sub nu/F/sub mu//sub nu/ coupling. A good fit is obtained. (AIP)
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)
14270584
Tau decays beyond the standard model
In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body τ decays. These parameters can be used to search for anomalous Γ L , Γ T polarized-partial widths, for non-CKM-type leptonic CP violation, and for leptonic T FS violation. They can also be used to bound the effective-mass scales A for “new physics” arising from additional Lorentz structures, e.g. from lepton compositeness, tau weak magnetism, weak electricity, or second-class currents. It is emphasized that (i) for these tests “different modes have different merits” and that (ii) the parameters can be measured either by using spin-correlation techniques without polarized beams, or with longitudinally polarized beams.