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Month

A Search for the Decay Modes B +/- to h +/- tau l (open access)

A Search for the Decay Modes B +/- to h +/- tau l

We present a search for the lepton flavor violating decay modes B{sup {+-}} {yields} h{sup {+-}} {tau}{ell} (h = K, {pi}; {ell} = e, {mu}) using the BABAR data sample, which corresponds to 472 million B{bar B} pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and {ell} candidates, we are able to fully determine the {tau} four-momentum. The resulting {tau} candidate mass is our main discriminant against combinatorial background. We see no evidence for B{sup {+-}} {yields} h{sup {+-}} {tau}{ell} decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10{sup -5}.
Date: July 20, 2012
Creator: Lees, J.P.
System: The UNT Digital Library
2012 ATOMIC AND MOLECULAR INTERACTIONS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, JULY 15-20, 2012 (open access)

2012 ATOMIC AND MOLECULAR INTERACTIONS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, JULY 15-20, 2012

At the 2012 Atomic and Molecular Interactions Gordon Conference, there will be talks in several broadly defined and partially overlapping areas:  Intramolecular and single-collision reaction dynamics;  Photophysics and photochemistry of excited states;  Clusters, aerosols and solvation;  Interactions at interfaces;  Conformations and folding of large molecules;  Interactions under extreme conditions of temperature and pressure. The theme of the Gordon Research Seminar on Atomic & Molecular Interactions, in keeping with the tradition of the Atomic and Molecular Interactions Gordon Research Conference, is far-reaching and involves fundamental research in the gas and condensed phases along with application of these ideas to practical chemical fields. The oral presentations, which will contain a combination of both experiment and theory, will focus on four broad categories:  Ultrafast Phenomena;  Excited States, Photoelectrons, and Photoions;  Chemical Reaction Dynamics;  Biomolecules and Clusters.
Date: July 20, 2012
Creator: Zwier, Timothy
System: The UNT Digital Library
Comparison of H-Mode Plasmas Diverted to Solid and Liquid Lithium Surfaces (open access)

Comparison of H-Mode Plasmas Diverted to Solid and Liquid Lithium Surfaces

Experiments were conducted with a Liquid Lithium Divertor (LLD) in NSTX. Among the goals was to use lithium recoating to sustain deuterium (D) retention by a static liquid lithium surface, approximating the ability of flowing liquid lithium to maintain chemical reactivity. Lithium evaporators were used to deposit lithium on the LLD surface. Improvements in plasma edge conditions were similar to those with lithiated graphite plasma-facing components (PFCs), including an increase in confinement over discharges without lithiumcoated PFCs and ELM reduction during H-modes. With the outer strike point on the LLD, the D retention in the LLD was about the same as that for solid lithium coatings on graphite, or about two times that achieved without lithium PFC coatings. There were also indications of contamination of the LLD surface, possibly due erosion and redeposition of carbon from PFCs. Flowing lithium may thus be needed for chemically active PFCs during long-pulse operation.
Date: July 20, 2012
Creator: R. Kaita, et. al.
System: The UNT Digital Library
Calculation of the Effect of Random Superfluid Density on the Temperature Dependence of the Penetration Depth (open access)

Calculation of the Effect of Random Superfluid Density on the Temperature Dependence of the Penetration Depth

Microscopic variations in composition or structure can lead to nanoscale inhomogeneity in superconducting properties such as the magnetic penetration depth, but measurements of these properties are usually made on longer length scales. We solve a generalized London equation with a non-uniform penetration depth {lambda}(r), obtaining an approximate solution for the disorder-averaged Meissner screening. We find that the effective penetration depth is different from the average penetration depth and is sensitive to the details of the disorder. These results indicate the need for caution when interpreting measurements of the penetration depth and its temperature dependence in systems which may be inhomogeneous.
Date: July 20, 2012
Creator: Lippman, Thomas & Moler, Kathryn A.
System: The UNT Digital Library