Events at Physics |
Events on Thursday, December 4th, 2014
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Particle Physics at the Highest Energies
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Peter Denton, Vanderbilt University
- Abstract: The highest energy scales accessible in particle physics are seen at the LHC and ultra high energy cosmic ray detectors such as Pierre Auger Observatory and Telescope Array. First, I consider applying a technique known as integral dispersion relations to extend the reach of the LHC. Integral dispersion relations use analyticity to link experimental values at one energy to those at all energies. This can be used to detect new physics in a model independent fashion at and above a machine's operating energy. Next, to probe physics at even higher energies, I consider the open question of ultra high energy cosmic ray anisotropy. In particular, I look at how problems such as low statistics and partial sky coverage affect an experiment's ability to determine anisotropy.
- Host: Westerhoff
- Astronomy Colloquium
- Cosmic-Ray Ionization Rates in the Galactic ISM
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall
- Speaker: Nick Indriolo, University of Michigan
- Abstract: Cosmic rays play a vital role in initiating the chemistry that occurs in molecular clouds. The ionization of H and H2 begins a network of ion-molecule reactions responsible for generating many of the diatomic and small polyatomic molecules observed in the interstellar medium. A few such species---HCO+, DCO+, OH+, H2O+, and H3+ in particular---are formed and destroyed by rather simple processes, making them powerful probes of the cosmic-ray ionization rate. I will discuss the current status of observations of these molecular ions within our Galaxy, as well as the conclusions that can be drawn from this ever-growing sample.