VERITAS Observations of M 87 in 2011/2012

The giant radio galaxy M 87 is located at a distance of 16.7 Mpc and harbors a super-massive black hole (6 billion solar masses) in its center. M 87 is one of just three radio galaxies known to emit TeV gamma-rays. The structure of its relativistic plasma jet, which is not pointing towards our line of sight, is spatially resolved in X-ray (Chandra), optical and radio (VLA/VLBA) observations. The mechanism and location of the TeV emitting region is one of the least understood aspects of AGN. In spring 2008 and 2010, the three TeV observatories VERITAS, MAGIC and H.E.S.S. detected two major TeV flares in coordinated observations. Simultaneous high-resolution observations at other wavelengths - radio (2008) and X-rays (2008/2010) - gave evidence that one of the TeV flares was related to an event in the core region; however, no common/repeated patterns could be identified so far. VERITAS continued to monitor M 87 in 2011/2012. The results of these observations are presented.Comment: 4 pages, 3 figures; conference proceedings of the 5th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma2012

D0D0bar Quantum Correlations, Mixing, and Strong Phases

Due to the presence of the quantum correlation between the pair-produced D0 and D0bar from the decay of the psi(3770), the time-integrated single and double tag decay rates depend on charm mixing amplitudes, doubly-Cabibbo-suppressed amplitudes, and the relative strong phase, delta, between D0 and D0bar decays to identical final states. Using 281 pb^-1 of integrated luminosity collected with the CLEO-c detector on the psi(3770) resonance, we measure the absolute branching fractions of D0 decays to K-pi+, CP eigenstates, and semileptonic final states to determine cos(delta) for K-pi+ and to limit the mixing amplitude y.Comment: 3 pages, to appear in the Proceedings of PANIC'05 (Particles and Nuclei International Conference), Santa Fe, NM, October 24-28 200