Measurements of Absolute Hadronic Branching Fractions of D Mesons

Using e+e- collisions recorded at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we determine absolute hadronic branching fractions of charged and neutral D mesons. Among measurements for both Cabibbo-favored and Cabibbo-suppressed modes, we obtain reference branching fractions B(D0 -> K-pi+)=(3.91 +- 0.08 +- 0.09)% and B(D+ -> K-pi+pi+)=(9.5 +- 0.2 +- 0.3)%, where the uncertainties are statistical and systematic, respectively. Using a determination of the integrated luminosity, we also extract the e+e- -> DDbar cross sections.Comment: 3 pages, to appear in the Proceedings of PANIC'05 (Particles and Nuclei International Conference), Santa Fe, NM, October 24-28 200

Simultaneous Least Squares Treatment of Statistical and Systematic Uncertainties

We present a least squares method for estimating parameters from measurements of event yields in the presence of background and crossfeed. We adopt a unified approach to incorporating the statistical and systematic uncertainties on the experimental measurements input to the fit. We demonstrate this method with a fit for absolute hadronic D meson branching fractions, measured in e+e- -> \psi(3770) -> D\bar D$ transitions.Comment: 9 pages, 2 figures; minor clarifications, one figure adde

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

Fast response time fiber optical pH and oxygen sensors

While fluorescence-based fiber optic sensors for measuring both pH and oxygen concentration (O2) are well known, current sensors are often limited by their response time and drift, which limits the use of existing fiber optic sensors of this type in wider applications, for example in physiology and other fields. Several new fiber optical sensors have been developed and optimized, with respect to key features such as tip shape and coating layer thickness. In this work, preliminary results on the performance of a suite of pH sensors with fast response times, < 3 second and oxygen sensors (O2) with response times < 0.2 second. The sensors have been calibrated and their performance analyzed using the Henderson–Hasselbalch equation (pH) and classic Lehrer-model (O2)

Bell Inequalities Classifying Bi-separable Three-qubit States

We present a set of Bell inequalities that gives rise to a finer classification of the entanglement for tripartite systems. These inequalities distinguish three possible bi-separable entanglements for three-qubit states. The three Bell operators we employed constitute an external sphere of the separable cube.Comment: 8 page

The X-ray coronae of the two brightest galaxies in the Coma cluster

We use deep Chandra X-ray Observatory observations to examine the coronae of the two brightest cluster galaxies in the Coma cluster of galaxies, NGC 4874 and NGC 4889. We find that NGC 4889 hosts a central depression in X-ray surface brightness consistent with a cavity or pair of cavities of radius 0.6 kpc. If the central cavity is associated with an AGN outburst and contains relativistic material, its enthalpy should be around 5x10^55 erg. The implied heating power of this cavity would be around an order of magnitude larger than the energy lost by X-ray emission. It would be the smallest and youngest known cavity in a brightest cluster galaxy and the lack of over pressuring implies heating is still gentle. In contrast, NGC 4874 does not show any evidence for cavities, although it hosts a well-known wide-angle-tail radio source which is visible outside the region occupied by the X-ray corona. These two galaxies show that AGN feedback can behave in varied ways in the same cluster environment.Comment: 11 pages, 11 figures, accepted by MNRA

Cooling in the X-ray halo of the rotating, massive early-type galaxy NGC 7049

The relative importance of the physical processes shaping the thermodynamics of the hot gas permeating rotating, massive early-type galaxies is expected to be different from that in non-rotating systems. Here, we report the results of the analysis of XMM-Newton data for the massive, lenticular galaxy NGC 7049. The galaxy harbours a dusty disc of cool gas and is surrounded by an extended hot X-ray emitting gaseous atmosphere with unusually high central entropy. The hot gas in the plane of rotation of the cool dusty disc has a multi-temperature structure, consistent with ongoing cooling. We conclude that the rotational support of the hot gas is likely capable of altering the multiphase condensation regardless of the $t_{\rm cool}/t_{\rm ff}$ ratio, which is here relatively high, $\sim 40$. However, the measured ratio of cooling time and eddy turnover time around unity ($C$-ratio $\approx 1$) implies significant condensation, and at the same time, the constrained ratio of rotational velocity and the velocity dispersion (turbulent Taylor number) ${\rm Ta_t} > 1$ indicates that the condensing gas should follow non-radial orbits forming a disc instead of filaments. This is in agreement with hydrodynamical simulations of massive rotating galaxies predicting a similarly extended multiphase disc.Comment: 11 pages, 12 figures, accepted for publication in MNRA