Measurement of eta photoproduction on the proton from threshold to 1500 MeV

Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.Comment: 18 pages, 14 figures, 4 tables Submitted to EPJ

Neutral pion photoproduction off protons in the energy range 0.3 GeV < E(gamma) < 3 GeV

Single pi0 photoproduction has been studied with the CB-ELSA experiment at Bonn using tagged photon energies between 0.3 and 3.0 GeV. The experimental setup covers a very large solid angle of about 98% of 4 pi. Differential cross sections (d sigma)/(d Omega) have been measured. Complicated structures in the angular distributions indicate a variety of different resonances being produced in the s channel intermediate state gamma p --> N* (Delta*) --> p pi0. A combined analysis including the data presented in this letter along with other data sets reveals contributions from known resonances and evidence for a new resonance N(2070)D15.Comment: LaTeX file, 4 pages, 4 encapsulated postscript figures, submitted to Phys. Rev. Lett. The publication of hep-ex/0407022 is accompanied by hep-ex/0311045 on photoproduction of eta mesons. Reference [3]: changed, reference [17]: citation added. Figure 3, 4: SAID added up to 2 GeV for comparison, update

Academic Performance and Behavioral Patterns

Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

Photoproduction of eta mesons off protons for photon energies from 0.75 GeV to 3 GeV

Total and differential cross sections for the reaction p(gamma, eta)p have been measured for photon energies in the range from 750 MeV to 3 GeV. The low-energy data are dominated by the S11 wave which has two poles in the energy region below 2 GeV. Eleven nucleon resonances are observed in their decay into p eta. At medium energies we find evidence for a new resonance N(2070)D15 with (mass, width) = (2068+-22, 295+-40) MeV. At photon energies above 1.5 GeV, a strong peak in forward direction develops, signalling the exchange of vector mesons in the t channel.Comment: LaTeX, 4 pages including 4 eps-figures, submitted to Phys. Rev. Lett. The publication of hep-ex/0311045 is accompanied by hep-ex/0407022 on photoproduction of neutral pions, submitted to Phys. Rev. Lett. Fits published in the latest version are based on additional data, new beam asymmetry data from GRAAL are included, for instance. The data demanded more resonant contributions which were studied in detail. PWA reference adde

Double jeopardy:subordinates' worldviews and poor performance as predictors of abusive supervision

Purpose - To test a moderated mediation model where a positive relationship between subordinates’ perceptions of a dangerous world—the extent to which an individual views the world as a dangerous place—and supervisory abuse is mediated by their submission to authority figures, and that this relationship is heightened for more poorly performing employees. Design/Methodology/Approach - Data were obtained from 173 subordinates and 45 supervisors working in different private sector organizations in Pakistan. Findings - Our model was supported. It appears that subordinates’ dangerous worldviews are positively associated with their perceptions of abusive supervision and that this is because such views are likely to lead to greater submission to authority figures. But this is only for those employees who are performing more poorly. Implications - We highlight the possibility that individual differences (worldviews, attitudes to authority figures, and performance levels) may lead employees to become victims of abusive supervision. As such, our research informs organizations on how they may better support supervisors in managing effectively their subordinate relationships and, in particular, subordinate poor performance. Originality/Value - We add to recent work exploring subordinate-focused antecedents of abusive supervision, finding support for the salience of the previously untested constructs of individual worldviews, authoritarian submission, and individual job performance. In so doing we also extend research on dangerous worldviews into a new organizational setting. Finally, our research takes place within a new Pakistani context, adding to the burgeoning non-US based body of empirical work into the antecedents and consequences of abusive supervision

The UKCAT-12 study: educational attainment, aptitude test performance, demographic and socio-economic contextual factors as predictors of first year outcome in a cross-sectional collaborative study of 12 UK medical schools

Most UK medical schools use aptitude tests during student selection, but large-scale studies of predictive validity are rare. This study assesses the United Kingdom Clinical Aptitude Test (UKCAT), and its four sub-scales, along with measures of educational attainment, individual and contextual socio-economic background factors, as predictors of performance in the first year of medical school training

Photon beam asymmetry Sigma for eta and eta ' photoproduction from the proton

Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $\gamma p \to \eta p$ reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the $\gamma p \to \eta^\prime p$ reaction. For $\gamma p \to \eta p$, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For $\gamma p \to \eta^\prime p$, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn-Gatchina model strengthens the evidence for four nucleon resonances -- the $N(1895)1/2^-$, $N(1900)3/2^+$, $N(2100)1/2^+$ and $N(2120)3/2^-$ resonances -- which presently lack the "four-star" status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process.Comment: 10 pages, 3 figure