The QweakQ_{weak} Experiment: First Determination of the Weak Charge of the Proton

The $Q_{weak}$ Collaboration has completed a challenging measurement of the parity-violating asymmetry in elastic electron-proton ($\vec{e}$p) scattering at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The initial result reported here is extracted from the commissioning part of the experiment, constituting about 4% of the full data set. The parity-violating asymmetry at a low momentum transfer $Q^2$=0.025 GeV$^2$ is $A_{ep}$ = -279 $\pm$ 35 (stat) $\pm$ 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in $\vec{e}$p scattering. This result allowed the first determination of the weak charge of the proton $Q_W^p$ from a global fit of parity-violating elastic scattering (PVES) results from nuclear targets, where earlier data at higher $Q^2$ constrain uncertainties of hadronic structure. The value extracted from the global fit is $Q_W^p$ (PVES) = 0.064 $\pm$ 0.012, in agreement with the standard model prediction $Q_W^p$ (SM) = 0.0710 $\pm$ 0.0007. The neutral weak charges of up and down quarks are extracted from a combined fit of the PVES results with a previous atomic parity violation (APV) measurement on $^{133}$Cs. The analysis of the full $Q_{weak}$ data is ongoing and expected to yield a value for the asymmetry within 10 ppb of precision. Because of the suppression of $Q_W^p$, such a high precision measurement will place significant constraints to models of physics beyond the standard model.Comment: Talk presented at CIPANP2015. 8 pages, LaTeX, 4 eps figure

THE VALUE OF \beta FROM THE LG AND ABELL CLUSTER PECULIAR VELOCITIES

Comparing the observed peculiar velocities of the Local Group and of nearby Abell clusters of galaxies with those predicted using linear perturbation theory and the 3-D reconstruction algorithm of Branchini \& Plionis (1995) the value of $\beta$ can be estimated. I show that the anisotropy that causes the LG motion does not only extend to very large depths ($\sim 160 \; h^{-1}$ Mpc) but it is also very coherent, which suggests that the value of $\beta \approx 0.21 \pm 0.015$, obtained from the LG velocity, should not be significantly affected by cosmic variance. Comparing the Abell cluster and QDOT galaxy dipoles in real space their relative biasing factor are estimated to be $b_{cI}\approx 3.5\pm0.5$. Finally, using a suitable set of available cluster peculiar velocities I obtain a somewhat lower value of $\beta\approx 0.15 - 0.17$ but with a large uncertainty ($\gtrsim 0.1$) when weighted by the large observational errors.Comment: 4 pages self unpacking compressed postscript file containing figures. Contribution to the XVth MORIOND astrophysics meeting (March 1995

Acceptance Rates in Physical Review Letters: No Seasonal Bias

Are editorial decisions biased? A recent discussion in Learned Publishing has focused on one aspect of potential bias in editorial decisions, namely seasonal (e.g., monthly) variations in acceptance rates of research journals. In this letter, we contribute to the discussion by analyzing data from Physical Review Letters (PRL), a journal published by the American Physical Society. We studied the 190,106 papers submitted to PRL from January 1990 until September 2012. No statistically significant variations were found in the monthly acceptance rates. We conclude that the time of year that the authors of a paper submit their work to PRL has no effect on the fate of the paper through the review process.Comment: Scheduled to appear in Learned Publishin

The Large-Scale Environment of Groups & Clusters of Galaxies

It appears that the dynamical status of clusters and groups of galaxies is related to the large-scale structure of the Universe. A few interesting trends have been established: (1) The Cluster Substructure - Alignment Connection, by which clusters show a strong correlation between their tendency to be aligned with their neighbors and their dynamical state (as indicated by the existence of significant substructres). (2) The Cluster Dynamics -Cluster Clustering Connection, by which dynamically young clusters are more clustered than the overall cluster population. (3) The Cluster- Supercluster Alignment Connection, by which clusters of galaxies show a statistical significant tendency to be aligned with the projected major axis orientation of their parent supercluster. (4) The Galaxy Alignment - Cluster Dynamics Connection, by which red-sequence cluster bright galaxies show a significant trend to be aligned with their parent cluster major axis, especially in dynamically young clusters. (5) The Group Richness - Shape Connection, by which groups of galaxies are flatter the poorer they are. These are strong indications that clusters develop in a hierarchical fashion by anisotropic merging of smaller units along the large-scale filamentary structures within which they are embedded.Comment: Invited Talk in IAU colloquium 195 (Torino, March 12-16 2004

Highlighting Impact and the Impact of Highlighting: PRB Editors' Suggestions

Associate Editor Manolis Antonoyiannakis discusses the highlighting, as Editors' Suggestions, of a small percentage of the papers published each week. We highlight papers primarily for their importance and impact in their respective fields, or because we find them particularly interesting or elegant. It turns out that the additional layer of scrutiny involved in the selection of papers as Editors' Suggestions is associated with a significantly elevated and sustained citation impact.Comment: Editoria

The Cluster Substructure - Alignment Connection

Using the APM cluster data we investigate whether the dynamical status of clusters is related to the large-scale structure of the Universe. We find that cluster substructure is strongly correlated with the tendency of clusters to be aligned with their nearest neighbour and in general with the nearby clusters that belong to the same supercluster. Furthermore, dynamically young clusters are more clustered than the overall cluster population. These are strong indications that cluster develop in a hierarchical fashion by anisotropy merging along the large-scale filamentary superclusters within which they are embedded.Comment: To appear in the Proceedings of `Galaxy Clusters and the High Redshift Universe Observed in X-rays', XXIth Moriond Astrophysics Meeting (March 2001), Eds. Doris Neumann et a

Representations of the Mapping Class Group of the Two Punctured Torus on the Space of \hat {sl}(2,C) Spin1/2-Spin1/2 Kac-Moody Blocks

The integral representations of the $\hat {sl}(2,C)$ Spin 1/2 - Spin 1/2 Kac-Moody Blocks on the torus, arising from the free field representation of the $\hat {sl}(2,C)$ Kac-Moody algebra of Wakimoto and Bernard and Felder, are used to derive an infinite class of representations of the mapping class group of the two punctured torus.Comment: 13 pages LaTeX, requires epsf, replaced TeX symbols in abstrac

Method and apparatus for automatic text input insertion in digital devices with a restricted number of keys

A device which contains number of symbol input keys, where the number of available keys is less than the number of symbols of an alphabet of any given language, screen, and dynamic reordering table of the symbols which are mapped onto those keys, according to a disambiguation method based on the previously entered symbols. The device incorporates a previously entered keystrokes tracking mechanism, and the key selected by the user detector, as well as a mechanism to select the dynamic symbol reordering mapped onto this key according to the information contained to the reordering table. The reordering table occurs from a disambiguation method which reorders the symbol appearance. The reordering information occurs from Bayesian Belief network construction and training from text corpora of the specific language.Comment: European patent offic

Incomplete Information in RDF

We extend RDF with the ability to represent property values that exist, but are unknown or partially known, using constraints. Following ideas from the incomplete information literature, we develop a semantics for this extension of RDF, called RDFi, and study SPARQL query evaluation in this framework

The Substructure-Alignment Connection

Using a sample of 903 APM clusters we investigate whether their dynamical status, as evidenced by the presence of significant substructures, is related to the large-scale structure of the Universe. We find that the cluster dynamical activity is strongly correlated with the tendency of clusters to be aligned with their nearest neighbour and in general with the nearby clusters that belong to the same supercluster. Furthermore, dynamically active clusters are more clustered than the overall cluster population. These are strong indications that clusters develop in a hierarchical fashion by anisotropic merging along the large-scale filaments within which they are embedded.Comment: 5 pages, accepted for publication in MNRAS pink page