Coronal Temperature Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration

The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray imager that observes the solar corona with unprecedentedly high angular resolution (consistent with its 1" pixel size). XRT has nine X-ray analysis filters with different temperature responses. One of the most significant scientific features of this telescope is its capability of diagnosing coronal temperatures from less than 1 MK to more than 10 MK, which has never been accomplished before. To make full use of this capability, accurate calibration of the coronal temperature response of XRT is indispensable and is presented in this article. The effect of on-orbit contamination is also taken into account in the calibration. On the basis of our calibration results, we review the coronal-temperature-diagnostic capability of XRT

Quadrupole Moments of Neutron-Deficient 20,21^{20, 21}Na

The electric-quadrupole coupling constant of the ground states of the proton drip line nucleus $^{20}$Na($I^{\pi}$ = 2$^{+}$, $T_{1/2}$ = 447.9 ms) and the neutron-deficient nucleus $^{21}$Na($I^{\pi}$ = 3/2$^{+}$, $T_{1/2}$ = 22.49 s) in a hexagonal ZnO single crystal were precisely measured to be $|eqQ/h| = 690 \pm 12$ kHz and 939 $\pm$ 14 kHz, respectively, using the multi-frequency $\beta$-ray detecting nuclear magnetic resonance technique under presence of an electric-quadrupole interaction. A electric-quadrupole coupling constant of $^{27}$Na in the ZnO crystal was also measured to be $|eqQ/h| = 48.4 \pm 3.8$ kHz. The electric-quadrupole moments were extracted as $|Q(^{20}$Na)$|$ = 10.3 $\pm$ 0.8 $e$ fm$^2$ and $|Q(^{21}$Na)$|$ = 14.0 $\pm$ 1.1 $e$ fm$^2$, using the electric-coupling constant of $^{27}$Na and the known quadrupole moment of this nucleus as references. The present results are well explained by shell-model calculations in the full $sd$-shell model space.Comment: Accepted for publication in Physics Letters

Nab: Measurement Principles, Apparatus and Uncertainties

The Nab collaboration will perform a precise measurement of 'a', the electron-neutrino correlation parameter, and 'b', the Fierz interference term in neutron beta decay, in the Fundamental Neutron Physics Beamline at the SNS, using a novel electric/magnetic field spectrometer and detector design. The experiment is aiming at the 10^{-3} accuracy level in (Delta a)/a, and will provide an independent measurement of lambda = G_A/G_V, the ratio of axial-vector to vector coupling constants of the nucleon. Nab also plans to perform the first ever measurement of 'b' in neutron decay, which will provide an independent limit on the tensor weak coupling.Comment: 12 pages, 6 figures, 1 table, talk presented at the International Workshop on Particle Physics with Slow Neutrons, Grenoble, 29-31 May 2008; to appear in Nucl. Instrum. Meth. in Physics Research

Simple method for excitation of a Bose-Einstein condensate

An appropriate, time-dependent modification of the trapping potential may be sufficient to create effectively collective excitations in a cold atom Bose-Einstein condensate. The proposed method is complementary to earlier suggestions and should allow the creation of both dark solitons and vortices.Comment: 8 pages, 7 figures, version accepted for publication in Phys. Rev.

The Energy Dependence of Stretched States Excited in (p,n) Reactions

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q^2

The A-dependence of the quasielastic A(e,e'p) reaction has been studied at SLAC with H-2, C, Fe, and Au nuclei at momentum transfers Q^2 = 1, 3, 5, and 6.8 (GeV/c)^2. We extract the nuclear transparency T(A,Q^2), a measure of the average probability that the struck proton escapes from the nucleus A without interaction. Several calculations predict a significant increase in T with momentum transfer, a phenomenon known as Color Transparency. No significant rise within errors is seen for any of the nuclei studied.Comment: 5 pages incl. 2 figures, Caltech preprint OAP-73

Stress, resilience, and cardiovascular disease risk among black women: Results from the women's health initiative

Background: Empirical data on the link between stress and cardiovascular disease (CVD) risk among black women is limited. We examined associations of stressful life events and social strain with incident CVD among black women and tested for effect modification by resilience. Methods and Results: Our analysis included 10 785 black women enrolled in the Women's Health Initiative Observational Study and Clinical Trials cohort. Participants were followed for CVD for up to 23 years (mean, 12.5). Multivariable Cox regression was used to estimate hazard ratios and 95% CIs for associations between stress-related exposures and incident CVD. We included interactions between follow-up time (age) and stressful life events because of evidence of nonproportional hazards. Effect modification by resilience was examined in the sub-cohort of 2765 women with resilience and stressful life events measures. Higher stressful life events were associated with incident CVD at ages 55 (hazard ratio for highest versus lowest quartile=1.80; 95% CI, 1.27-2.54) and 65 (hazard ratio for highest versus lowest quartile=1.40; 95% CI, 1.16-1.68), but not at older ages. Adjustment for CVD risk factors attenuated these associations. Similar associations were observed for social strain. In the sub-cohort of women with updated stressful life events and resilience measures, higher stressful life events were associated with incident CVD in multivariable-adjusted models (hazard ratio=1.61; 95% CI, 1.04-2.51). Resilience did not modify this association nor was resilience independently associated with incident CVD. Conclusions: In this cohort of older black women, recent reports of stressful life events were related to incident CVD. Resilience was unrelated to incident CVD. Clinical Trials Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00000611

β-delayed particle decay of 9C and the A = 9, T = 1/2 nuclear system: Experiment, data, and phenomenological analysis

The β decay of 9C (T1/2 = 126.5 ms) has been studied in two experiments observing about 15 × 107 and 8 × 107 decays, respectively, at the TISOL facility at TRIUMF; different detector configurations were employed in the two experiments. In this first of two papers, the two experimental setups are described, as well as data analysis and a phenomenological approach to deducing branching ratios to and from states in 9B. In the experiments single spectra, and double and triple coincidence spectra, were recorded. Several states in 9B were observed; β-branching ratios to these states, and particle decay channels from these states, are reported. In particular, secondary decays into the 5Li and 8Be ground states were observed. With the inclusion of a considerable continuum and additional states, fair agreement with the reported 9Li logft values is found with a phenomenological approach for deducing the branching ratios. To extend the discussion, in a second, forthcoming paper, a multichannel, multistate R-matrix analysis of these data will be described

β-delayed particle decay of 17ne into p + α + 12C through the isobaric analog state in 17F

We have observed the breakup of the isobaric analog state at 11.193 MeV in 17F into three particles via three channels: proton decay to the α-unbound 9.585 MeV state in 16O; and α decay to the proton-unbound 2.365 and 3.502/3.547 MeV states in 13N. Laboratory α-particle spectra corresponding to these three modes have been generated in Monte Carlo simulations using single-channel, single- and multilevel R-matrix formulas. A fit of these spectra to the α spectrum resulting from a triple-coincidence measurement results in excellent agreement with the experimental spectrum and allows branching ratios to be deduced for these rare decay modes

The Q2Q^2-dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron

The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution to the magnetic moment of the target nucleus with an energy-weighted integral of the difference of the helicity-dependent photoabsorption cross sections. The data collected by HERMES with a deuterium target are presented together with a re-analysis of previous measurements on the proton. This provides a measurement of the generalised GDH integral covering simultaneously the nucleon-resonance and the deep inelastic scattering regions. The contribution of the nucleon-resonance region is seen to decrease rapidly with increasing $Q^2$. The DIS contribution is sizeable over the full measured range, even down to the lowest measured $Q^2$. As expected, at higher $Q^2$ the data are found to be in agreement with previous measurements of the first moment of $g_1$. From data on the deuteron and proton, the GDH integral for the neutron has been derived and the proton--neutron difference evaluated. This difference is found to satisfy the fundamental Bjorken sum rule at $Q^2 = 5$ GeV$^2$.Comment: 12 pages, 10 figure