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We consider the class of effective supergravity theories from the weakly coupled heterotic string in which local supersymmetry is broken by gaugino condensation in a hidden sector, with dilaton stabilization achieved through corrections to the classical dilaton Kahler potential. If there is a single hidden condensing (simple) gauge group, the axion is massless (up to contributions from higher dimension operators) above the QCD condensation scale. We show how the standard relation between the axion mass and its Planck scale coupling constant is modified in this class of models due to a contribution to the axion-gluon coupling that appears below the scale of supersymmetry breaking when gluinos are integrated out. In particular there is a point of enhanced symmetry in parameter space where the axion mass is suppressed. We revisit the question of the universal axion as the Peccei-Quinn axion in the light of these results, and find that the strong CP problem is avoided in most compactifications of the weakly coupled heterotic string.

We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. it is important to the ongoing ILC design effort to demonstrate that these tolerances can be achieved--ideally using beam-based stability measurements. It has been estimated that an RF cavity BPM with modern waveform processing could provide a position measurement resolution of less than one nanometer. Such a system could form the basis of the desired beam-based stability measurement, as well as be used for other specialized purposes. They have developed a high resolution RF cavity BPM and associated electronics. A triplet comprised of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. The three BPMs are rigidly mounted inside an alignment frame on six variable-length struts which can be used to move the BPMs in position and angle. they have developed novel methods for extracting the position and tilt information from the BPM signals including a robust calibration algorithm which is immune to beam jitter. To date, they have been able to demonstrate a resolution of approximately 20 nm over a dynamic range of {+-} …

Ion tracking and ion-track lithography have been performed almost exclusively using ions with energies near or above the maximum in electronic stopping, which occurs at {approx}1 MeV/amu. In this paper, ion-track lithography using ions with energies well below this maximum is discussed. The results of etching ion tracks created in polycarbonate films by ions with energies just above the anticipated threshold for creating etchable latent tracks with cylindrical geometry have been examined. Low-energy neon and argon ions with 18-60 keV/amu and fluences of {approx}10{sup 8}/cm{sup 2} were used to examine the limits for producing useful, etchable tracks in polycarbonate films. By concentrating on the early stages of etching (i.e., {approx}20 nm < SEM hole diameter < {approx}100 nm), the energy deposition calculated for the incident ion was correlated with the creation of etchable tracks. The experimental results are discussed with regard to the energy losses of the ions in the polycarbonate films and to the formation of continuous latent tracks through the entire thickness of the films. The probability distributions for large-angle scattering events were calculated to assess their importance as a function of ion energy. All these results have significant implications with respect to the threshold for formation of …

A photograph of Dolores Huerta on a stage in one of UNT's lecture halls. A man is placing a white regalia hood over her shoulders after she received an honorary degree from the university. There are two framed objects behind the group on stage.

A photograph of a group of people standing on a stage in one of UNT's lecture halls. They are clapping for Dolores Huerta, who is standing with them to recieve her honorary Doctorate of Humane Letters, and there are three framed items on the stage. The items are a painting used for the League of Professional Women group, a UNT document with a seal, and an honorary degree.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.

Photograph of a scene during the Civilian Conservation Corps statue unveiling ceremony at the Oklahoma History Center.