Backgrounds to the detection of two-body hadronic B decays (open access)

Backgrounds to the detection of two-body hadronic B decays

We consider backgrounds to the detection of the two-body hadronic decay modes of neutral B mesons and baryons. The largest background is due to the correlated production of pairs of high-p/sub T/ hadrons in the target, but this can be adequately rejected provided the experimental apparatus has sufficient resolution in mass and decay vertex. Another possible source of background arises from the production and decay of charmed and strange particles. Since these particles can travel considerable distances before decaying, they can give rise to backgrounds which may not be rejectable by means of vertex cut. We have simulated several backgrounds from charm, and we find them to be small compared to the expected level of signal. 8 refs., 1 fig., 2 tabs
Date: January 8, 1988
Creator: Kaplan, D. M.; Peng, Jen-Chieh; Abrams, G. S. & Stockdale, I. E.
System: The UNT Digital Library
Present capabilities and new developments in antenna modeling with the numerical electromagnetics code NEC (open access)

Present capabilities and new developments in antenna modeling with the numerical electromagnetics code NEC

Computer modeling of antennas, since its start in the late 1960's, has become a powerful and widely used tool for antenna design. Computer codes have been developed based on the Method-of-Moments, Geometrical Theory of Diffraction, or integration of Maxwell's equations. Of such tools, the Numerical Electromagnetics Code-Method of Moments (NEC) has become one of the most widely used codes for modeling resonant sized antennas. There are several reasons for this including the systematic updating and extension of its capabilities, extensive user-oriented documentation and accessibility of its developers for user assistance. The result is that there are estimated to be several hundred users of various versions of NEC world wide. 23 refs., 10 figs.
Date: April 8, 1988
Creator: Burke, G. J.
System: The UNT Digital Library
Search for a QGP with a TPC spectrometer, and QGP signals predicted by new event generator (open access)

Search for a QGP with a TPC spectrometer, and QGP signals predicted by new event generator

The BNL/CCNY/Johns Hopkins/Rice Collaboration has developed and successfully tested a TPC Magnetic Spectrometer to search for OGP signals produced by ion beams at AGS. Test data with 14.5 GeV/c /times/ A Oxygen ions incident on a Pb target has been obtained. These include a 78-prong nuclear interaction in the MPS magnet which was pattern recognized with an efficiency approx.75%. A cascade and plasma event generator has also been developed, the predictions of which are used to illustrate how our technique can detect possible plasma signals at AGS and RHIC. A 4..pi.. tracking TPC magnetic spectrometer has been proposed for RHIC. The new event generator predicts striking central rapidity bump QGP signals at RHIC for p, /bar p/, ..pi../sup +-/, K/sup +-/, etc., produced by 100 GeV/c /times/ A Au on Au collisions and these are presented. 2 refs., 13 figs., 1 tab.
Date: December 8, 1988
Creator: Lindenbaum, S. J.
System: The UNT Digital Library
X-ray diffractometry of lanthanum-nickel-aluminum alloys. Part 1 (open access)

X-ray diffractometry of lanthanum-nickel-aluminum alloys. Part 1

X-ray diffractometry provides much useful information on LANA alloys that complements data obtained by SEM and Electron Microprobe Analysis. Accurate measurements of the hexagonal lattice parameters of the primary LaNi{sub 5-y}Aly phase reveal the aluminum content (y) and allow the prediction of desorption pressures for the hydrogen isotopes. A study of the broadening of x-ray diffraction lines of the LaNi{sub 5-y}Aly primary phase caused by cyclic absorption and desorption of hydrogen suggests that substitution of aluminum for nickel stabilizes the primary phase with respect to formation of antistructure defects that could cause undesirable trapping of hydrogen isotopes. Correlation of XRD with SEM and EMPA results has helped identify secondary phases, determine their abundances in volume percent, and reveal how they react with hydrogen and the atmosphere. Characterizations of LANA alloys used in process development has provided the bases for development of specifications for alloys to be used in the Replacement Trittium Facility. 28 refs., 4 tabs., 12 figs.
Date: August 8, 1988
Creator: Mosley, W. C.
System: The UNT Digital Library
Hyperfine interactions, the key to multiquark physics (open access)

Hyperfine interactions, the key to multiquark physics

Clues in the search for a fundamental description of hadron physics based on QCD may be obtained from a phenomenological constituent quark model in which the color-electric force binds quarks into saturated color-singlet hadrons, and finer details of the spectrum and multiquark physics are dominated by the color-magnetic hyperfine interaction. 47 refs.
Date: August 8, 1988
Creator: Likpink, H.J.
System: The UNT Digital Library
Study of heavy ion beams during longitudinal compression using particle simulation (open access)

Study of heavy ion beams during longitudinal compression using particle simulation

Particle simulations show that during longitudinal compression, there is little growth in beam longitudinal and transverse emittance. Both longitudinal and transverse temperatures follow adiabatic laws. The compressed beam has negligible longitudinal momentum spread and therefore can satisfy stringent requirements for final focusing. 4 refs., 3 figs.
Date: August 8, 1988
Creator: Ho, D.D.M. & Brandon, S.T.
System: The UNT Digital Library
X-ray diffractometry of lanthanum-nickel-aluminum alloys (open access)

X-ray diffractometry of lanthanum-nickel-aluminum alloys

X-ray diffractometry provides much useful information on LANA alloys that complements data obtained by SEM and Electron Microprobe Analysis. Accurate measurements of the hexagonal lattice parameters of the primary LaNi{sub 5-y}Aly phase reveal the aluminum content (y) and allow the prediction of desorption pressures for the hydrogen isotopes. A study of the broadening of x-ray diffraction lines of the LaNi{sub 5-y}Aly primary phase caused by cyclic absorption and desorption of hydrogen suggests that substitution of aluminum for nickel stabilizes the primary phase with respect to formation of antistructure defects that could cause undesirable trapping of hydrogen isotopes. Correlation of XRD with SEM and EMPA results has helped identify secondary phases, determine their abundances in volume percent, and reveal how they react with hydrogen and the atmosphere. Characterizations of LANA alloys used in process development has provided the bases for development of specifications for alloys to be used in the Replacement Trittium Facility. 28 refs., 4 tabs., 12 figs.
Date: August 8, 1988
Creator: Mosley, W. C.
System: The UNT Digital Library
Charge and angular correlated inelasticities in MeV/nucleon ion-atom collisions (open access)

Charge and angular correlated inelasticities in MeV/nucleon ion-atom collisions

Using an Elbek high-resolution magnetic spectrograph, we measured energy loss an angular distributions of MeV/nucleon projectile ions in coincidence with target recoil-ion charge state. We investigated collisions of 10 and 20 MeV C/sup 6 +/ on He, Ne, Ar, and Kr where the target atom is multiply ionized and the projectile emerges in charge state q or q-1. The amount of energy transferred to the continuum electrons exceeds, by far, the sum of the values of the ionization potentials and shows a strong target Z dependence. Both an n-body classical-trajectory Monte Carlo method (nCTMC) and an energy deposition model are used for comparison with the experimental data. 12 refs., 3 figs.
Date: November 8, 1988
Creator: Schoene, H.; Schuch, R.; Datz, S.; Dittner, P. F.; Giese, J. P.; Krause, H. F. et al.
System: The UNT Digital Library