We present a precise isospin analysis of the B -> (D) over bar (()*())D(()*())K decays using new recent experimental measurements on these final states. The decays B -> (D) over bar (()*())D(()*())K, originating from b -> c (c) over bars transitions, are linked by a rich set of isospin properties. The isospin relations that connect the decay modes are presented and a fit is performed to obtain the isospin amplitudes and phases. We discuss the results of the fit and present a new measurement of the ratio of branching fractions B(gamma(45) -> B(+)B(-)) and 8(gamma(4S) -> B(0)(B) over bar (0)). We finally discuss the implications of our findings for the measurement of the unitarity matrix parameters sin(2 beta) and cos(2 beta) using these decays. (C) 2011 Elsevier B.V. All rights reserved.

Magnet Safety Systems (MSS) frequently use quench detection based on voltage measurement, in order to protect superconducting magnets. Disconnecting quench detection cables and using a voltage generator to simulate quench voltages is a good way to check the system. This paper describes another method, with a hardware and software in-line control system, used to periodically check the MSS of the 28 superconducting magnets of the T2K proton beam line, at J-PARC. With in-line control, an isolated simulation voltage is added to each real input voltage of the detectors, without disconnecting quench detection cables. In-line control can also check if quench detection cables are connected or not, and if a detection wire is broken. In-line control is realized with additional electronic hardware and software on the MSS electronic boards and with a connection to a PC with a specific software and Graphic User Interface running under Windows. Nevertheless, quench detection and safety actions are always based on hardware only. Extreme care is taken so that in-line control cannot prevent the MSS to protect the magnet system, even if software stops running. Other remote functions are also available with this system, like monitoring of analog and logical signals and setting of detection and electronic parameters, if needed.

The T2K (Tokai-to-Kamioka) experiment is a long baseline neutrino oscillation experiment in Japan, for which a near detector complex (ND280), used to characterize the beam, will be built 280 m from the target in the off-axis direction of the neutrino beam produced using the 50 GeV proton synchrotron of J-PARC (Japan Proton Accelerator Research Complex). The central part of the ND280 is a detector including 3 large Time Projection Chambers based on Micromegas gas amplification technology with anodes pixelated into about 125,000 pads and requiring therefore compact and low power readout electronics. A 72-channel front-end Application Specific Integrated Circuit has been developed to read these TPCs. Each channel includes a low noise charge preamplifier, a pole zero compensation stage, a second order Sallen-Key low pass filter and a 511-cell Switched Capacitor Array. This electronics offers a large flexibility in sampling frequency (50 MHz max.), shaping time (16 values from 100 ns to 2 mu s), gain (4 ranges from 120 W to 600 fC), while taking advantage of the low physics events rate of 0.3 Hz. Fabricated in 0.35 mu m CMOS technology, the prototype has been validated and meets all the requirements for the experiment so that mass production has been launched at the end of 2007.