A search for t -> tau nu q in t(t)over-bar production

We present a search for t (t) over bar events with a tau lepton in the final state. The data sample corresponds to an integrated luminosity of 194 pb(-1) collected with the CDF II detector from p (p) over bar collisions at a center of mass energy of 1.96 TeV. We observe two events with an expected signal of 1.0 +/- 0.2 events and a background of 1.3 +/- 0.3 events. We determine a 95% confidence level upper limit on r(tau), the ratio of the measured rate of t -> tau nu q to the expectation, of 5.2

Performance of the ATLAS Detector using First Collision Data

More than half a million minimum-bias events of LHC collision data were collected by the ATLAS experiment in December 2009 at centre-of-mass energies of 0.9 TeV and 2.36 TeV. This paper reports on studies of the initial performance of the ATLAS detector from these data. Comparisons between data and Monte Carlo predictions are shown for distributions of several track- and calorimeter-based quantities. The good performance of the ATLAS detector in these first data gives confidence for successful running at higher energies