[en] Preliminary results on the photoproduction of light vector mesons in nuclei using the Cebaf Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory are presented. The ?, ?, and ? mesons are clearly observed via their decay to e+e-. This decay channel reduces the effects of final state interactions in the nucleus. Of particular interest are the possible in-medium effects on the properties of the ? meson. The ? mass spectrum is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from deuterium, which is relatively free of nuclear effects. No effects on the mass of the ? meson are observed, however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.

[en] Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The properties of the A vector mesons were investigated via their rare leptonic decay to e+e . After subtracting the combinatorial background, the A meson mass distributions were extracted for each of the targets. We observe no effects on the mass of the A meson, some widening in titanium and iron is observed consistent with the collisional broadening.

[en] Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. The light vector mesons (rho, omega, and phi) were photo-produced on H-2, C, Ti, Fe, and Pb targets at the Thomas Jefferson National Laboratory using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV . The properties of the rho vector meson at normal nuclear densities and zero temperature,were investigated via their rare leptonic decay to e+e?. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing techn

[en] Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the rho vector mesons were investigated via their rare leptonic decay to e+e?. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The rho meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the rho meson in the nuc

[en] This paper describes the influences of oil revenue and government's policies toward economic developments and energy efficiency on the electricity and water demands. A Kuwait-specific electricity and water demand model was developed based on historic data of oil income, gross domestic product (GDP), population and electric load and water demand over the past twelve years (1998–2010). Moreover, the model took into account the future mega projects, annual new connected loads and expected application of energy conservation programs. It was run under six circumstances representing the combinations of three oil income scenarios and two government action policies toward economic diversification and energy conservation. The first government policy is the status quo with respect to economic diversification and applying energy conservation programs. The second policy scenario is the proactive strategy of raising the production of the non-oil sector revenue and enforcing legislations toward energy demand side management and conservation. In the upcoming 20 years, the average rates of change of the electric load and water demand increase are 0.13 GW and 3.0 MIGD, respectively, per US dollar oil price increase. Moreover, through proactive policy, the rates of average load and water demand decrease are 0.13 GW and 2.9 MIGD per year, respectively. - Highlights: • Kuwait-specific electricity and water demand model is presented. • Strong association between oil income and electricity and water demands. • Rate of change of electric load per US dollar oil price change is 0.13 GW. • Rate of change of water demand per US dollar oil price change is 3.0 MIGD. • By 2030, efficiency lowers electric load and water demand by 10 and 6%, respectively

[en] In this article, we report on on investigations of the in-medium meson-nucleon interaction for the ω, φ, and K_s⁰ mesons. Their in-medium cross sections and collisional widths can be measured by their absorption in a nucleus. In Hall B at the Thomas Jefferson National Accelerator Facility (JLab), the CLAS detector was used to study these long-lived mesons in nuclei. All of the mesons were produced by a photon beam with Eγ < 4 GeV in targets of ²H, C, Fe, and Pb. The vector mesons were reconstructed through their decay into e⁺e^-. The K_s⁰ mesons were measured with their dominant π⁺π^- decay. The in-medium widths of the ω and φ mesons are found to be substantially larger than their values from the elementary reaction with a free nucleon. The analysis with the K_s⁰ is preliminary, and its status will be discussd in this paper.

[en] Ongoing work at the Z Machine on the development of warm x-ray sources in support of national security missions requires fast x-ray diagnostics with sensitivities significantly higher than what is commercially available. Our team represents a collaborative effort between MESA and Z to fabricate GaAs x-ray detectors that meet this need. The delivered detectors have now been fielded in several Z shot series and are providing hard x-ray data to physicists at Z. In addition to improved time response and hard x-ray sensitivity compared to commercial detectors, the devices fabricated at MESA show much more consistent device-to-device signal levels. This improved repeatability gives researchers at Z new quantitative data for source development efforts.

[en] The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance scale experiments has been a major challenge. Various QCD-inspired models predict a partial restoration of chiral symmetry in nuclear matter with modifications of the properties of hadrons from their free-space values. Measurable changes such as a shift in mass and/or a change of width are predicted at normal nuclear density. Photoproduction of vector mesons off nuclei have been performed at different laboratories. The properties of the ρ, ωψ mesons are investigated either directly by measuring their mass spectra or indirectly through transparency ratios. The latest results regarding medium modifications of the vector mesons in the nuclear medium will be discussed.

[en] The properties of hadrons, such as their masses and widths, are predicted to be modified in dense and/or hot nuclear matter. Particular attention has been given to the modifications of vector-meson properties in ordinary nuclear matter where chiral symmetry is predicted to be partially restored due to a change in the quark condensate. Different models predict relatively large measurable changes in the mass and/or the width of these mesons. The e⁺e^- decay channel of these mesons has negligible final-state interactions (FSI), providing an ideal tool to study their possible in-medium modifications Due to its short lifetime, the ρ meson has a substantial probability of decaying in the nucleus and its study has been previously reported. Due to their long lifetimes, the ω and φ mesons are ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. These mesons have been photo-produced in several targets ranging from deuterium to lead. Nuclear transparencies ratios have been derived for different decay channels. These ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSATAPS experiment. These results are compared to recent theoretical models.

[en] One of the most challenging aspects of Cu damascene fabrication is obtaining uniformly clear via hole bottoms following etch and clean. Residues and excess CuOx growth are common sources of high resistance and electro-migration failure. In this paper we describe a method of characterizing via bottoms in dense 0.12 um via structures that have been etched and cleaned prior to barrier/seed deposition. The technique used in this study is a non-destructive laser measurement method that is sensitive to the absorption of residues and oxides in the via bottom