E. Iacopini

Experimental method to detect the vacuum birefringence induced by a magnetic field

Abstract In this letter a method of measuring the birefringence induced in vacuum by a magnetic field is described: this effect is evaluated using the non-linear Euler-Heisenberg-Weisskopf lagrangian. The optical apparatus discussed here mau detect an induced ellipticity on a laser beam down to 10 −11 .

Digital techniques applied to phase-sensitive detection

A phase-sensitive detector, based on digital techniques, has been designed and tested. The main features of this instrument are presented and compared with those of a commercial analogue device.

Measurement of the 2S12−2P12 splitting in the (μ−4He)+ muonic ion

Abstract The measurement of the 2S 1 2 → 2P 1 2 energy transition in muonic helium is presented. The energy difference S1 is found to be Sexp1 = 1381.3±0.5 meV. This result agrees with the expected value S 1 = 1381.2±0.3 meV obtained assuming the previously measured value for the 2S 1 2 → 2P 3 2 energy difference.

Search for decays of the W± and Z bosons into quark-antiquark pairs

Abstract The invariant mass distribution of jet pairs observed in the UA2 central calorimeter is examined in the search for an excess of events in the region of the W ± and Z bosons, which would reveal their decays into quark-antiquark pairs. We give a detailed account of the methods of analysis used to optimize the mass resolution achieving ≅±10%. A structure is observed at the level of ≅ 3 standard deviations in the mass region of W ± and Z with shape and position consistent with expectation from their qqdecays. It contains 632 ± 190 events, 1.4 standard deviations above the standard model prediction of 340 ± 80 events.

Measurement of the magnetic birefringence in oxygen and nitrogen gases

Abstract The Cotton-Mouton constant for oxygen and nitrogen has been measured at room temperature and pressure using a laser with λ = 514.5 nm .

Magnetic birefringence measurement in hydrogen and deuterium gases

The first measurement of the magnetic birefringence (Cotton–Mouton effect) in molecular hydrogen and deuterium has been performed. The Cotton–Mouton constant of H2 and D2 has been measured at room temperature, atmospheric pressure, and for λ=514.5 nm. Comparison with theoretical calculations shows very good agreement in both cases.

Effects of a magnetic field on the optical properties of dielectric mirrors

AbstractWe have measured the changes in the polarization state of a monochromatic (λ=514.5 nm) light beam on reflection at normal incidence by a multilayer dielectric mirror placed in a time-modulated magnetic field. The dominant effect is a Faraday rotationΦ≃3.7×10−10 rad/G. The sensitivity (around 40Hz) obtained isn

Muonic X-rays and Muon Capture in Low Pressure Argon

simeq 6 times 10^{ - 9} {text{ rad/}}sqrt {{text{Hz}}}