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We present the result of our most recent search for T-violation in 205 Tl, which is interpreted in terms of an electric dipole moment of the electron de. We find de = (6.9 ± 7.4) × 10 −28 e cm. The present apparatus is a major upgrade of the atomic beam magnetic-resonance device used to set the previous limit on de. PACS numbers: 11.30.Er, 14.60.Cd, 32.10.Dk We report a new result in the search for the electric dipole moment (EDM) of the electron, a quantity of interest in connection with CP violation and extensions to the standard model of particle physics [1][2][3]. In heavy paramagnetic atoms an electron EDM results in an atomic EDM enhanced by a factor R ≡ d atom /d e . Thus we search for a permanent EDM of atomic thallium in the 6 2 P 1/2 F = 1 ground state, where R −585 [4]. Experimental MethodLike its predecessor [5,6], the new experiment [7] uses magnetic resonance with two oscillating rf fields [8] separated by a space containing an intense electric field E, and employs laser optical pumping for state selection and analysis. To control systematic effects arising from motional magnetic fields E × v/c, the previous experiment employed a single pair of counterpropagating vertical atomic beams. The present experiment has two pairs separated by 2.54 cm, each consisting of Tl and Na (see Fig.1). The spatially separated beams are nominally exposed to identical magnetic but opposite electric fields; this provides common-mode noise rejection and control of some systematic effects. Sodium serves as a comagnetometer: it is susceptible to the same systematic effects but insensitive to d e , since R is roughly proportional to the cube of the nuclear charge. Furthermore, sodium's two 3 2 S 1/2 ground state hyperfine levels F =2, 1 have g F = ±1/2, which in principle permits the separation of two different types of motional field effects. Figure 1 shows a schematic diagram of the experiment with the up beams active. Atoms leave the trichamber oven thermally distributed among the ground state hyperfine levels. After some collimation they enter the quantizing magnetic field B, nominally in theẑ direction and typically 0.38 Gauss. Laser beams then depopulate the states with non-zero magnetic quantum numbers m F . Thus, in the first optical region 590 nm z polarized light selects the m F = 0 Zeeman sublevel of either the F = 2 or the F = 1 Na ground state. (B Tl cos ω Tl t + B Na cos ω Na t)x, where 2B Tl = B Na and 1.506ω Tl ω Na . These resonant fields apply 'π/2' pulses, creating coherent superpositions of the m F = 0 states of each species. The atoms then move into the electric field, nominally parallel or anti-parallel to B. Typically |E| = 1.23 × 10 5 V/cm. The second rf field is coherent with the first, differing only by a relative phase shift α. In the analysis regions the atoms are probed with the same laser that performed the state selection. Fluorescence photons accompanying the atomic decays are reflected by polished aluminum paraboloids into Winston cones [9] made of UV-transmitting plastic. These lightpi...

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ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.