3,487 research outputs found

    Tests of Transfer Reaction Determinations of Astrophysical S-Factors

    Get PDF
    The 16O(3He,d)17F{}^{16}O ({}^{3}He,d) {}^{17}F reaction has been used to determine asymptotic normalization coefficients for transitions to the ground and first excited states of 17F{}^{17}F. The coefficients provide the normalization for the tails of the overlap functions for 17F16O+p{}^{17}F \to{}^{16}O + p and allow us to calculate the S-factors for 16O(p,γ)17F{}^{16}O (p,\gamma){}^{17}F at astrophysical energies. The calculated S-factors are compared to measurements and found to be in very good agreement. This provides the first test of this indirect method to determine astrophysical direct capture rates using transfer reactions. In addition, our results yield S(0) for capture to the ground and first excited states in 17F^{17}F, without the uncertainty associated with extrapolation from higher energies.Comment: 6 pages, 2 figure

    Introduction to The Special Issue: Advances in Methods and Measurement in Family Psychology

    Get PDF
    This special issue presents a collection of reports that highlight recent advances in methods and measurement and also shed light on the complexity of family psychology. The importance of theory in guiding solid family science is evident throughout these reports. The reports include guides for researchers who incorporate direct observation into their research protocols and the ever-expanding field of tele-health interventions. Advanced analytic approaches are offered in the areas of grid sequence analysis, latent fixed-effects models, and the Factors of Curves Model (FOCUS). These sophisticated analytic approaches may be applied to advance systemic thinking in family psychology. The last set of articles illustrate how complex and innovative methodologies are applied to address important societal issues. Work experiences and marital relationships in African American couples address the importance of spillover effects in contemporary families. The creation of biobehavioral plasticity index has the potential to inform gene x environment contributions to family functioning. Finally, the unique methodological issues that are particularly germane to the diverse nature of stepfamilies and nonresident fathers are addressed. We hope that readers of this special issue will return to these reports as resources and examples of theory-driven methods and measurements

    Asymptotic Normalization Coefficients for 13C+p->14N

    Get PDF
    The 13C(14N,13C)14N^{13}C(^{14}N,^{13}C)^{14}N proton exchange reaction has been measured at an incident energy of 162 MeV. Angular distributions were obtained for proton transfer to the ground and low lying excited states in 14N^{14}N. Elastic scattering of 14N^{14}N on 13C^{13}C also was measured out to the rainbow angle region in order to find reliable optical model potentials. Asymptotic normalization coefficients for the system 13C+p14N^{13}C+p\to {}^{14}N have been found for the ground state and the excited states at 2.313, 3.948, 5.106 and 5.834 MeV in 14N^{14}N. These asymptotic normalization coefficients will be used in a determination of the S-factor for 7Be(p,γ)8B^{7}Be(p,\gamma)^{8}B at solar energies from a measurement of the proton transfer reaction 14N(7Be,8B)13C^{14}N(^{7}Be,^{8}B)^{13}C.Comment: 5 pages, 6 figure

    Big Gay Church: Religion, Religiosity, and Visual Culture

    Get PDF
    Five academics explore their performed occupations of the National Art Education Association Annual Meetings. They have annually mounted Big Gay Church (BGC) services that deconstruct and question the ways visual culture, media representations, scriptural interpretations, and religious teaching have constructed (at times harmful) depictions of lesbian, gay, bisexual, transgender, queer and questioning (LGBTQ2) subjects. This essay recounts how co-authors have drawn on their multiple experiences with/in churches to play with religious rituals and narratives in ways that queerly comment on the damage or support organized religions offer LGBTQ2 students and educators

    Convergence and stability theorems for the Picard-Mann hybrid iterative scheme for a general class of contractive-like operators

    Get PDF
    In this paper we use the general class of contractive-like operators introduced by Bosede and Rhoades (J. Adv. Math. Stud. 3(2):1-3, 2010) to prove strong convergence and stability results for Picard-Mann hybrid iterative schemes considered in a real normed linear space. We establish the strong convergence and stability of the Picard iterative scheme as a corollary. Our results generalize and improve a multitude of results in the literature, including the recent results of Chidume (Fixed Point Theory Appl. 2014:233, 2014)

    Weighing Super-Massive Black Holes with Narrow Fe Kα\alpha Line

    Full text link
    It has been suggested that the narrow cores of the Fe Kα\alpha emission lines in Active Galactic Nuclei (AGNs) are likely produced in the torus, the inner radius of which can be measured by observing the lag time between the VV and KK band flux variations. In this paper we compare the virial products of the infrared time lags and the narrow Fe Kα\alpha widths for 10 type 1 AGNs with the black hole masses from other techniques. We find the narrow Fe Kα\alpha line width is in average 2.60.4+0.9^{+0.9}_{-0.4} times broader than expected assuming an isotropic velocity distribution of the torus at the distance measured by the infrared lags. We propose the thick disk model of the torus could explain the observed larger line width. Another possibility is the contamination by emission from the broad line region or the outer accretion disk. Alternatively, the narrow iron line might originate from the inner most part of the obscuring torus within the sublimation radius, while the infrared emission from outer cooler part. We note the correlation between the black hole masses based on this new technique and those based on other known techniques is statistically insignificant. We argue that this could be attributed to the small sample size and the very large uncertainties in the measurements of iron K line widths. The next generation of X-ray observatories could help verify the origin of the narrow iron Kα\alpha line and the reliability of this new technique.Comment: 12 pages, 2 figures, 2 tables, Science China G, in pres

    Multiple electromagnetic electron positron pair production in relativistic heavy ion collisions

    Get PDF
    We calculate the cross sections for the production of one and more electron-positron pairs due to the strong electromagnetic fields in relativistic heavy ion collisions. Using the generating functional of fermions in an external field we derive the N-pair amplitude. Neglecting the antisymmetrisation in the final state we find that the total probability to produce N pairs is a Poisson distribution. We calculate total cross sections for the production of one pair in lowest order and also include higher-order corrections from the Poisson distribution up to third order. Furthermore we calculate cross sections for the production of up to five pairs including corrections from the Poisson distribution.Comment: 13 pages REVTeX, 4 Postscript figures, This and related papers may also be obtained from http://www.phys.washington.edu/~hencken
    corecore