### Session K1: Astroparticle Symposium V: UHE Cosmic Rays - Auger North and Exotics

Chair: Gordon Thomson, University of Utah
Room: Green Center 211

 Saturday, October 24, 2009 1:50PM - 2:14PM K1.00001: The Northern Site of the Pierre Auger Observatory Invited Speaker: David Nitz The Pierre Auger Observatory is a multi-national project for research on ultra-high energy cosmic rays. The Southern Auger Observatory (Auger South) in Mendoza province, Argentina, was completed in 2008 with an instrumented area of 3,000 km$^2$. Science results form Auger South motivate the completion and extension of the investigations begun there by constructing the Northern Auger Observatory (Auger North), with a much larger acceptance for the extremely rare cosmic ray events above a few times $10^{19}$ eV. Auger North will have an instrumented area of 8,000 square miles (20,000 km$^2$) in Southeast Colorado, USA. The presentation covers the science of Auger North, the layout and the technical implementation, as well as current R\&D efforts underway in Colorado. Saturday, October 24, 2009 2:14PM - 2:26PM K1.00002: Development of Atmospheric Monitoring System for Auger North John Claus , Clint Allen , Adam Botts , Bryce Carande , Mike Calhoun , Lucas Emmert , Levi Hamilton , T.J. Heid , John Koop , Sarah Morgan , Shay Robinson , John Sherman , Lawrence Wiencke The Pierre Auger Northern Fluorescence Detector will measure air-showers over distances of 40 km. Vertical Aerosol profile of the atmosphere at the Pierre Auger Northern site will be measured using the side-scatter method over the 40 km baseline. An atmospheric monitoring telescope (AMT) will use a 3.5 m$^2$ mirror optimized for UV reflection to focus light from a laser onto a cluster of phototmultiplier tubes. The AMT has been built and final testing and modifications are being carried out before its installation later this year. A remotely programmed, 355 nm YAG laser with a final beam energy of 5 mJ is being used. The automation of the laser and the AMT is controlled via a single board computer (SBC). This talk will present an overview of this R\&D program. Saturday, October 24, 2009 2:26PM - 2:38PM K1.00003: Identification of clear atmospheric conditions in a search for exotic candidates at the Pierre Auger Observatory David Starbuck Stable periods of clear and cloudless atmospheric conditions were identified using data from the Pierre Auger Observatory's Central Laser Facility. The objecive of this study is to assist in a search for exotic signatures. This search uses longitudinal profiles reconstructed from data recorded by fluorescence detectors. Longitudinal profiles that show exotic behavior are usually caused by cloudy or hazy atmospheric conditions. Signatures that fit this description can be eliminated by limiting the search to periods of clear atmospheric conditions. Saturday, October 24, 2009 2:38PM - 2:50PM K1.00004: Measuring the speed resolution of extensive air showers at the Southern Pierre Auger Observatory Kathleen Gesterling , Fred Sarazin Ultra-high energy cosmic rays induce extensive air showers (EASs) in Earth's atmosphere which are assumed to propagate at the speed of light. The fluorescence detector (FD) at the Southern Pierre Auger Observatory detects the light signal from the EAS and directly measures the energy of the cosmic ray. When two or more FD sites observe an event, the geometry of the shower can be calculated independently of the velocity it is traveling. It is then possible to fit the time profile recorded in the FD using the shower speed as a free parameter. The analysis of a collection of stereo events allowed us to determine with what speed resolution we can measure EASs with sensitivity to subluminal components. Knowing the speed resolution we can look for objects propagating significantly below the speed of light. Saturday, October 24, 2009 2:50PM - 3:02PM K1.00005: Using Bayesian Inference to Determine Upper Limits on Exotic Cosmic Ray Composition Fractions David Schuster A method for determining cosmic ray composition fractions using Bayesian inference is presented. By systematically comparing observables from simulated extensive air showers to a given set of data, this method sets an upper limit on the compositional makeup of the data. The method is demonstrated on a simulated dataset of known composition and applications to a search for exotic particles in the Southern Pierre Auger Observatory dataset are discussed.