Test of "crab-waist" collisions at the DAPhiNE Phi factory.

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA.

Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.

[Assessment of plasma lipid profile in acute coronary syndromes. The use of fibrinolytics and heparin do not affect it significantly]. / Andamento del profilo lipidico plasmatico nelle sindromi coronariche acute. L'uso di fibrinolitici ed eparina non lo modificano significativamente.

BACKGROUND: Neurohormonal and metabolic responses to acute ischemic events associated with thrombolysis and heparin induce substantial changes in the lipid profile (acute phase response). The aim of this study was to assess changes in total cholesterol and triglycerides in patients with acute coronary syndrome, admitted to our Intensive Coronary Care Unit (ICCU). METHODS: The study included 1051 consecutive patients, 316 with unstable angina, 583 with Q wave acute myocardial infarction (AMI) and 152 with non-Q wave AMI. Total cholesterol and triglycerides were measured in all patients at time 0 (admission), at time 1 (the morning following admission), at time 2 (the morning after discontinuation of heparin treatment). RESULTS: The mean value of total cholesterol at admission was 235, 210 and 197 mg% at admission, time 1 and time 2, respectively. Triglyceride levels were 234, 178 and 189 mg%, respectively. In the subgroup of thrombolized AMI the reduction in total cholesterol at time 1 and time 2 resulted similar in comparison with non-thrombolized AMI (p = NS). The decrease in triglycerides showed a similar pattern in the different subgroups. Comparison was also done according to sex, age, and complications. CONCLUSIONS: These data confirm that mean total cholesterol and triglycerides at admission are sharply higher than values considered normal in the literature. Within 24 hours of admission there is a 10.7% drop in total cholesterol which increases to 16.2% after a few days (mean 3.4 days). Total cholesterol determination upon admission in patients with acute coronary syndromes is necessary in order to know the true concomitant lipid profile during the precipitating ischemic events. The decision of initiating early therapy with statins would then appear more justified.