arXiv subjects

K. Honscheid

Publications and source records attributed to K. Honscheid.

585 records · Page 33Linked to original sources

arXiv2009

An Analysis of DES Cluster Simulations through the IMCAT and Shapelets Weak Lensing Pipelines

We have run two completely independent weak lensing analysis pipelines on a set of realistic simulated images of a massive galaxy cluster with a singular isothermal sphere profile (galaxy velocity dispersion sigma_v=1250 km/ sec). The suite of images was constructed using the simulation tools developed by the Dark Energy Survey. We find that both weak lensing pipelines can accurately recover the velocity dispersion of our simulated clusters, suggesting that current weak lensing tools are accurate enough for measuring the shear profile of massive clusters in upcoming large photometric surveys. We also demonstrate how choices of some cuts influence the final shear profile and sigma_v measurement. Analogously to the STEP program, we make all of these cluster simulation images publically available for other groups to analyze through their own weak lensing pipelines.

astro-ph.IM↗

arXiv2009

Particle Physics and Astrophysics -- A whitepaper in response to a call to the Astronomy and Astrophysics Community from the Committee on Astro2010 for State of the Profession Position Papers

We discuss some of the key science questions that are bringing particle physicists and astrophysicists together, and comment on some of the cultural and funding issues that have arisen as these two communities become increasingly intertwined.

astro-ph.CO↗

arXiv2008

The Dark Energy Camera (DECam)

In this paper we describe the Dark Energy Camera (DECam), which will be the primary instrument used in the Dark Energy Survey. DECam will be a 3 sq. deg. mosaic camera mounted at the prime focus of the Blanco 4m telescope at the Cerro-Tololo International Observatory (CTIO). It consists of a large mosaic CCD focal plane, a five element optical corrector, five filters (g,r,i,z,Y), a modern data acquisition and control system and the associated infrastructure for operation in the prime focus cage. The focal plane includes of 62 2K x 4K CCD modules (0.27"/pixel) arranged in a hexagon inscribed within the roughly 2.2 degree diameter field of view and 12 smaller 2K x 2K CCDs for guiding, focus and alignment. The CCDs will be 250 micron thick fully-depleted CCDs that have been developed at the Lawrence Berkeley National Laboratory (LBNL). Production of the CCDs and fabrication of the optics, mechanical structure, mechanisms, and control system for DECam are underway; delivery of the instrument to CTIO is scheduled for 2010.

astro-ph↗

arXiv2001

The Power Supply System of the CLEO III Silicon Detector

The CLEO III detector has recently commenced data taking at the Cornell electron Storage Ring (CESR). One important component of this detector is a 4 layer double-sided silicon tracker with 93% solid angle coverage. This detector ranges in size and number of readout channels between the LEP and LHC silicon detectors. In order to reach the detector performance goals of signal-to-noise ratios greater than 15:1 low noise front-end electronics together with highly regulated low noise power supplies were used. In this paper we describe the low-noise power supply system and associated monitoring and safety features used by the CLEO III silicon tracker.

hep-ex↗

arXiv1996

Nonleptonic Decays and Lifetimes of b-quark and c-quark Hadrons

We review recent experimental results on lifetimes and hadronic decays of hadrons that contain $c$ and $b$ quarks. The theoretical implications of these results are also considered. An understanding of hadronic decays of heavy quarks is required to interpret the CP violating asymmetries in $B$ decays that will be observed in experiments planned for the near future.

hep-ph↗

arXiv1995

The Cherenkov Correlated Timing Detector: Materials, Geometry and Timing Constraints

The key parameters of Cherenkov Correlated Timing (CCT) detectors are discussed. Measurements of radiator geometry, optical properties of radiator and coupling materials, and photon detector timing performance are presented.

hep-ex↗

arXiv1995

The Cherenkov Correlated Timing Detector: Beam Test Results from Quartz and Acrylic Bars

Several prototypes of a Cherenkov Correlated Timing (CCT) Detector have been tested at the KEK-PS test beam line. We describe the results for Cherenkov light yields and timing characteristics from quartz and acrylic bar prototypes. A Cherenkov angle resolution is found to be 15 mrad at a propagation distance of 100 cm with a 2 cm thick quartz bar prototype.

hep-ex↗

arXiv1994

Semileptonic B Meson Decays and Interfering Amplitudes

Consequences of the interference between external and internal spectator amplitudes for the lifetimes and semileptonic decay fractions of $B^0$ and $B^+$ mesons are discussed. Extrapolating from the constructive interference observed in 11 exclusive hadronic $B$ decays we find an inclusive semileptonic decay fraction of $(11.2 \pm 0.5 \pm 1.7)$\%, significantly closer to the experimental results than previous predictions.

hep-ph↗

arXiv1993

The Semileptonic Decay Fraction of B Mesons in the Light of Interfering Amplitudes

Consequences of the interference between spectator amplitudes for the lifetimes and semileptonic decay fractions of B^0 and B^+ mesons are discussed. Assuming duality and constructive interference between spectator amplitudes we are able to explain the low experimental value for the semileptonic decay fraction of $B$ mesons. Extracting these amplitudes from a fit to 11 exclusive hadronic B decay fractions we find a_1 = 1.05 +/- 0.03 +/- 0.10, a_2 =+0.227 +/ 0.012 +/- 0.022, an inclusive semileptonic decay fraction of (11.2 +/- 0.5 +/- 1.7), and a lifetime ratio tau(B^+) / tau(B^0) = 0.83 +/- 0.01 +/- 0.01.

hep-ph↗