Search for b0(s) --> mu+ mu- and b0(d) --> mu+ mu- decays in p anti-p collisions at s**(1/2) = 1.96 tev (open access)

Search for b0(s) --> mu+ mu- and b0(d) --> mu+ mu- decays in p anti-p collisions at s**(1/2) = 1.96 tev

The authors report on a search for B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays in p{bar p} collisions at {radical}s = 1.96 TeV using 171 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are sensitive to contributions from physics beyond the Standard Model. One event survives all the selection requirements, consistent with the background expectation. They derive branching ratio limits of {Beta}(B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 5.8 x 10{sup -7} and {Beta}(B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 1.5 x 10{sup -7} at 90% confidence level.
Date: March 20, 2004
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
Simulating the Flow Field Upstream of the Dworshak Dam Regulating Outlets (open access)

Simulating the Flow Field Upstream of the Dworshak Dam Regulating Outlets

The Pacific Northwest National Laboratory numerically modeled flow conditions upstream of the regulating outlets at Dworshak Dam, North Fork Clearwater River, Idaho. Simulations were performed using the computational fluid dynamics model Flow-3D, a peer reviewed and validated three-dimensional Reynolds-averaged Navier-Stokes hydrodynamic model. Results were studied to determine the impacts of water surface elevation and discharge though the three regulating outlets on flow velocities in the reservoir forebay. These simulations were in general support of a larger research program conducted by the Idaho Department of Fish and Game that is evaluating the efficacy of strobe lights to deter fish from entering the regulating outlets and powerhouse turbine intakes. Simulation results indicate that large variations in forebay water velocities occur over the typical range of regulating outlet operations and seasonal water surface fluctuations. As expected, water velocities generally increase with larger outlet gate openings and higher water surface elevations. Simulations span typical regulating outlet operations: forebay water surface elevations between 1460 ft and 1600 ft and regulating outlet gate valve openings between 1 ft and 10 ft open. In addition, simulations examined flow conditions when only one or two of the three regulating outlets were operating. The resulting matrix of 24 unique …
Date: March 20, 2004
Creator: Cook, Chris B. & Richmond, Marshall C.
Object Type: Report
System: The UNT Digital Library
X-ray Polarization Measurements at Relativistic Laser Intensities (open access)

X-ray Polarization Measurements at Relativistic Laser Intensities

An effort has been started to measure the short pulse laser absorption and energy partition at relativistic laser intensities up to 10{sup 21} W/cm{sup 2}. Plasma polarization spectroscopy is expected to play an important role in determining fast electron generation and measuring the electron distribution function.
Date: March 20, 2004
Creator: Beiersdorfer, P; Shepherd, R; Mancini, R C; Chen, H; Dunn, J; Keenan, R et al.
Object Type: Article
System: The UNT Digital Library