A CCD vertex deetctor for a high-energy linear e+e- collider

I present a summary of the experience with CCD-based vertex detectors at the SLD experiment at SLAC, and discuss their advantages for use at a future high-energy e+e- collider. The extensive R+D programme to improve further the vertexing capabilities of CCD detectors is also outlined.Comment: 14 pages latex including 4 embedded ps files, to appear in Proceedings Vertex99 Worksho

The Direct Detectability of Giant Exoplanets in the Optical

Motivated by the possibility that a coronagraph will be put on WFIRST/AFTA, we explore the direct detectability of extrasolar giant planets (EGPs) in the optical. We quantify a planet's detectability by the fraction of its orbit for which it is in an observable configuration ($f_\mathrm{obs}$). Using a suite of Monte Carlo experiments, we study the dependence of $f_\mathrm{obs}$ upon the inner working angle (IWA) and minimum achievable contrast ($C_\mathrm{min}$) of the direct-imaging observatory; the planet's phase function, geometric albedo, single-scattering albedo, radius, and distance from Earth; and the semi-major axis distribution of EGPs. We calculate phase functions for a given geometric or single-scattering albedo, assuming various scattering mechanisms. We find that the Lambertian phase function can predict significantly larger $f_\mathrm{obs}$'s with respect to the more realistic Rayleigh phase function. For observations made with WFIRST/AFTA's baseline capabilities ($C_\mathrm{min}\sim10^{-9}$, $\mathrm{IWA}\sim0.2''$), Jupiter-like planets orbiting stars within 10, 30, and 50 parsecs of Earth have volume-averaged observability fractions of ${\sim}$12%, 3%, and 0.5%, respectively. At 10 parsecs, such observations yield $f_\mathrm{obs}>1\%$ for low- to modest-eccentricity planets with semi-major axes in the range ${\sim}2 - 10$ AU. If $C_\mathrm{min}=10^{-10}$, this range extends to ${\sim}35$ AU. We find that, in all but the most optimistic configurations, the probability for detection in a blind search is low (${<}\,5\%$). However, with orbital parameter constraints from long-term radial-velocity campaigns and Gaia astrometry, the tools we develop in this work can be used to determine both the most promising systems to target and when to observe them.Comment: 16 pages, 16 figures. Accepted for publication in Ap

Summary of Discussion Question 4: Energy Expandability of a Linear Collider

We report on Discussion Question 4, in Sub-group 1 (`TeV-class') of the Snowmass Working Group E3: `Experimental Approaches: Linear Colliders', which addresses the energy expandability of a linear collider. We first synthesize discussions of the energy reach of the hardware of the 500 GeV designs for TESLA and NLC/JLC. Next, we review plans for increasing the energy to 800-1000 GeV. We then look at options for expanding the energies to 1500 GeV and sketch the two-beam accelerator approach to achieving multi-TeV energies.Comment: Presented at Snowmass 2001 (6 pages, 2 figures