Coherent Photoproduction of pi^+ from 3^He

We have measured the differential cross section for the $\gamma$$^3$He$\rightarrow \pi^+ t$ reaction. This reaction was studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with the Hall-B bremsstrahlung tagging system in the energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid $^3$He target. The differential cross sections for the $\gamma$$^3$He$\rightarrow \pi^+ t$ reaction were measured as a function of photon-beam energy and pion-scattering angle. Theoretical predictions to date cannot explain the large cross sections except at backward angles, showing that additional components must be added to the model.Comment: 11 pages, 16 figure

Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive π0\pi^0 production

We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial $\sin \phi_h$ amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle $\phi_h$ of the produced neutral pion. The dependence of this amplitude on Bjorken $x$ and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.Comment: to be submitted PL

Evidence for a backward peak in the gamma+d->pi^0+d cross section near the eta threshold

High-quality cross sections for the reaction gamma+d->pi^0+d have been measured using the CLAS at Jefferson Lab over a wide energy range near and above the eta-meson photoproduction threshold. At backward c.m. angles for the outgoing pions, we observe a resonance-like structure near E_gamma=700 MeV. Our model analysis shows that it can be explained by eta excitation in the intermediate state. The effect is the result of the contribution of the N(1535)S_11 resonance to the amplitudes of the subprocesses occurring between the two nucleons and of a two-step process in which the excitation of an intermediate eta meson dominates.Comment: slightly modified title, additional paragraph and a table (Table 2) added on p. 5; to be submitted to EPJA, 6 pages, 3 figure

Hyperuricaemia and gout in New Zealand rural and urban Māori and non-Māori communities

Background: There are few current data on the prevalence of hyperuricaemia and gout in New Zealand, particularly among the indigenous Māori population. Aims: To determine the prevalence of gout and hyperuricaemia in rural and urban Māori and non-Māori community samples and describe the treatment and comorbidities of participants with gout. Methods: Participants aged 20-64 years were recruited by random selection from the electoral roll. Māori samples were selected from among those identified as being of Māori descent on the roll and who self-identified as being of Māori ethnicity at interview. Personal medical history, blood pressure, anthropometrics, fasting lipids, glucose, HbA1c and urate were recorded. Results: There were 751 participants. Mean serum urate (SU) was 0.30 mmol/L (0.06-0.69 mmol/L). Māori had a significantly higher prevalence of hyperuricaemia (SU > 0.40 mmol/L) compared with non-Māori (17.0% vs 7.5%, P = 0.0003). A total of 57 participants had a history of gout, with a higher prevalence in Māori compared with non-Māori (10.3% vs 2.3%, P 0.36 mmol/L. Participants with gout were more likely to have metabolic syndrome, diabetes, cardiac disease or hypertension. Conclusions: Gout and hyperuricaemia were more prevalent in Māori, and participants with gout were more likely to have comorbidities. There was not a higher overall adjusted cardiovascular disease risk in Māori participants with gout. Despite the high prevalence of gout, management remains suboptimal. (© 2012 The Authors; Internal Medicine Journal © 2012 Royal Australasian College of Physicians.