Neutron Beam Effects on Spin Exchange Polarized He-3

We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable He-3 polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation over a range of neutron fluxes at LANSCE and ILL. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as the square root of the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the recombination-limited ion concentration, but is much larger than expected from earlier work.Comment: submitted to Physical Review Letter

High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents

We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 \pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.Comment: 5 pages and 5 figures. Paper accepted for publication in Phys. Rev. Let

One-Particle Measurement of the Antiproton Magnetic Moment

\DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace} \DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace} \DeclareRobustCommand{\mup}{$\mu_{p}${}{}\xspace} \DeclareRobustCommand{\mupbar}{\mu_{\pbar}{}{}\xspace} \DeclareRobustCommand{\muN}{$\mu_N${}{}\xspace For the first time a single trapped \pbar is used to measure the \pbar magnetic moment {\bm\mu}_{\pbar}. The moment {\bm\mu}_{\pbar} = \mu_{\pbar} {\bm S}/(\hbar/2) is given in terms of its spin ${\bm S}$ and the nuclear magneton (\muN) by \mu_{\pbar}/\mu_N = -2.792\,845 \pm 0.000\,012. The 4.4 parts per million (ppm) uncertainty is 680 times smaller than previously realized. Comparing to the proton moment measured using the same method and trap electrodes gives \mu_{\pbar}/\mu_p = -1.000\,000 \pm 0.000\,005 to 5 ppm, for a proton moment ${\bm{\mu}}_{p} = \mu_{p} {\bm S}/(\hbar/2)$, consistent with the prediction of the CPT theorem.Comment: 4 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1201.303

Polarization and relaxation of radon

Investigations of the polarization and relaxation of $^{209}$Rn by spin exchange with laser optically pumped rubidium are reported. On the order of one million atoms per shot were collected in coated and uncoated glass cells. Gamma-ray anisotropies were measured as a signal of the alignment (second order moment of the polarization) resulting from the combination of polarization and quadrupole relaxation at the cell walls. The temperature dependence over the range 130$^\circ$C to 220$^\circ$C shows the anisotropies increasing with increasing temperature as the ratio of the spin exchange polarization rate to the wall relaxation rate increases faster than the rubidium polarization decreases. Polarization relaxation rates for coated and uncoated cells are presented. In addition, improved limits on the multipole mixing ratios of some of the main gamma-ray transitions have been extracted. These results are promising for electric dipole moment measurements of octupole-deformed $^{223}$Rn and other isotopes, provided sufficient quantities of the rare isotopes can be produced.Comment: 4 pages, 4 figure

Prevalence of diabetic and impact on cardiovascular events and mortality in patients with chronic coronary syndromes, across multiple geographical regions and ethnicities

Background: In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity. Methods: CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia and Africa in 2009-2010, and followed-up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischemia, or prior revascularisation procedure. Results: Among 32,694patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to approximately 60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome(cardiovascular death, myocardial infarction or stroke)with an adjusted hazard ratio of1.28(95% CI 1.18-1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest. Conclusion: In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes

Two-neutron transfer reaction mechanisms in 12^{12}C(6^6He,4^{4}He)14^{14}C using a realistic three-body 6^{6}He model

The reaction mechanisms of the two-neutron transfer reaction $^{12}$C($^6$He,$^4$He) have been studied at 30 MeV at the TRIUMF ISAC-II facility using the SHARC charged-particle detector array. Optical potential parameters have been extracted from the analysis of the elastic scattering angular distribution. The new potential has been applied to the study of the transfer angular distribution to the 2$^+_2$ 8.32 MeV state in $^{14}$C, using a realistic 3-body $^6$He model and advanced shell model calculations for the carbon structure, allowing to calculate the relative contributions of the simultaneous and sequential two-neutron transfer. The reaction model provides a good description of the 30 MeV data set and shows that the simultaneous process is the dominant transfer mechanism. Sensitivity tests of optical potential parameters show that the final results can be considerably affected by the choice of optical potentials. A reanalysis of data measured previously at 18 MeV however, is not as well described by the same reaction model, suggesting that one needs to include higher order effects in the reaction mechanism.Comment: 9 pages, 9 figure

New generalized fuzzy metrics and fixed point theorem in fuzzy metric space

In this paper, in fuzzy metric spaces (in the sense of Kramosil and Michalek (Kibernetika 11:336-344, 1957)) we introduce the concept of a generalized fuzzy metric which is the extension of a fuzzy metric. First, inspired by the ideas of Grabiec (Fuzzy Sets Syst. 125:385-389, 1989), we define a new G-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by M Grabiec). Next, inspired by the ideas of Gregori and Sapena (Fuzzy Sets Syst. 125:245-252, 2002), we define a new GV-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by V Gregori and A Sapena). Moreover, we provide the condition guaranteeing the existence of a fixed point for these single-valued contractions. Next, we show that the generalized pseudodistance J:X×X→[0,∞) (introduced by Włodarczyk and Plebaniak (Appl. Math. Lett. 24:325-328, 2011)) may generate some generalized fuzzy metric NJ on X. The paper includes also the comparison of our results with those existing in the literature

High-precision branching-ratio measurement for the superallowed β\u3csup\u3e+\u3c/sup\u3e emitter 74Rb

A high-precision branching-ratio measurement for the superallowed β+ decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted β particles; the 8π spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting γ rays that were emitted following Gamow-Teller and nonanalog Fermi β+ decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring β-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4)×108 detected 74Rb β decays. A total of 58 γ-ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B 0=99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed ft value of 3082.8(65) s. Comparisons between this superallowed ft value and the world-average-corrected Ft̄ value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region. © 2013 American Physical Society

Probing the low-lying level structure of 94Zr through β¯ decay

223-227Low-lying states of 94Zr are populated following b- decay of 94Y, and the emitted g rays from 94Zr are detected using the 8p spectrometer composed of 20 Compton-suppressed HPGe detectors. High- statistics coincidence data have been used for the placement of very weak decay branches in the level scheme. Combining the results of level lifetimes from a previous experiment and the precisely measured branching ratio values of the weak decay branches from the present experiment, it is possible to extract the B(E2) values for all the possible decay branches from a given level. These values are helpful for proper identification of the collective and non-collective states of 94Zr. The experimental findings have been compared with predictions from shell-model calculations with a limited valence space; however, these calculations are inadequate in reproducing all of the measured spectroscopic quantities