A storage ring experiment to detect a proton electric dipole moment.

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10-29 e ⋅ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

Effect of an educational program in primary care: the case of lipid control in cardio-cerebrovascular prevention.

Lowering blood cholesterol levels reduces the risk of coronary heart disease. However, the effect of interventions depends on the patients' adherence to treatment. Primary care plays an important role in the detection, treatment and monitoring of disease, therefore different educational programs (EP) have been implemented to improve disease management in general practice. The present study is aimed to assess whether a general practitioner auditing and feedback EP may improve dyslipidaemia management in a primary care setting and to evaluate patients' adherence to prescribed lipid-lowering treatment. The quality of cardiovascular and cerebrovascular disease prevention before and after the implementation of an EP offered to 25 general practitioners (GPs), was evaluated. Clinical and prescription data on patients receiving at least one lipid-lowering treatment was collected. To evaluate the quality of the healthcare service provided, clinical and biochemical outcomes, and drug-utilization, process indicators were set up. Adherence was evaluated before and after the EP as the "Medication Possession Ratio" (MPR). A correlation analysis was carried out to estimate the effect of the MPR in achieving pre-defined clinical end-points. Prescription data for lipid-lowering drugs was collected in a sample of 839 patients. While no differences in the achievement of blood lipid targets were observed, a slight but significant improvement of the MPR was registered after the EP (MPR >0.8=64.2% vs 60.6%, p=0.0426). Moreover, high levels of statin adherence were associated with the achievement of total blood cholesterol target (OR=3.3 for MPR >0.8 vs MPR <0.5, 95% CI:1.7-6.7) or LDL therapeutic goal (OR=3.3 for MPR >0.8 vs MPR <0.5, 95% CI:1.5-7.2). The EP partially improved the defined clinical targets; probably, a more patient-based approach could be more appropriate to achieve the defined target. Further studies are needed to identify how healthcare services can be improved.

Overcoming depolarizing resonances with dual helical partial Siberian snakes.

Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

Polarized proton collisions at 205 GeV at RHIC.

The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

Observation of higher-order snake resonances in polarized proton acceleration in RHIC.

Higher-order and coupled snake resonances were observed during the 2002 polarized proton run in RHIC. Strong depolarization was observed when the fractional part of the vertical betatron tune approached 1/4, and when the fractional part of the horizontal tune approached 3/14. Because of the closed orbit error, each snake resonance splits into two. From the width of the observed snake resonances, we can derive the strength of the imperfection spin resonance. Our results appear consistent with the measured closed orbit error.

Observation of a hybrid spin resonance

A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This "hybrid" spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors.

Coherent compton x-ray sources.

Coherent x rays can be produced by scattering of laser light by a beam of relativistic electrons, provided that the electron beam is density modulated or the scattering is done at, or near, 90°. Since the coherent scattering is proportional to N2, where N is the number of electrons, and the incoherent scattering is proportional to N, also a modest degree of coherence can substantially increase the x-ray yield. The theory of laser-electron-beam scattering is reviewed and compared with the emission of radiation by an electron beam in an undulator. Examples of the practical implementation of an intense source of coherent x rays are discussed.