118487890
Search for photoproduction of psi (3105)
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.
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)
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.
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.
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.
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.
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.
121781054
Relativistic dispersion analysis of R in the 4-GeV region
115882781
Cheng-wu picture applied to gamma p ---> rho0 p and phi p
16089695
Spin--unitary-spin splitting of SU(8) supermultiplets
The suprising narrowness of the J or psi (3.1) is interpreted as indication of a pure cc state, and hence as evidence for the SU(8) ..-->.. SU(6) x SU(2)/subS//subc/ x U(1)/subY//subc/ symmetry-breaking chain (S/subc/ = charmed-quark--spin generators, Y/subc/ = hypercharm generator) instead of an approximate SU(8) ..-->.. SU(4) x SU(2)/subS/ chain (S = quark spin generators) which would imply strong mixings. Decompositions under both chains of the s-wave qq meson states of the 64 = 1 + 63 of SU(8) and of the 3q baryon states of the three-particle symmetric 120 representation are given. The most general mass-splitting operators with breaking in the Y and Y/subc/ directions for these two multiplets are derived, which commute with the Casimir operators of the SU(6) x SU(2)/subS//subc/ x U(1)/subY//subc/ chain, which contain only one- and two-body operators, and which are invariant under rotations. Two independent mass relations follow for mesons containing charmed quarks; six, for baryons containing charmed quarks. In an appendix, for reference relative to previous SU(6) -symmetric quark-model mass analyses, the reduced numerical coefficients as determined by the meson 36 of SU(6) are listed. (AIP)