Events at Physics
Events on Thursday, May 16th, 2013
- Theory Seminar (High Energy/Cosmology)
- Dark Matter Searches Using Radio Waves and Neutrinos
- Time: 11:00 am
- Place: 5280 Chamberlin Hall
- Speaker: Ranjan Laha, Ohio State University
- Abstract: The particle nature of dark matter is one of the biggest mysteries of present day science. I will discuss some of the efforts in detecting dark matter through radio waves and neutrinos. I will first talk about the recent hint of a 130 GeV gamma-ray line from the Galactic Center in the Fermi-LAT data. I will show that current radio observations of the Galactic Center marginally constrain the interpretation of the claimed gamma lines, independent of the underlying particle physics model, for a contracted NFW profile. Radio data of the Galactic Center with existing telescopes will play an important role in confirming or ruling out the dark matter interpretation of the gamma-ray line. I will then talk about neutrinos as a probe of dark matter. Neutrinos are the best probe of TeV-scale dark matter annihilation signal and I will show that galaxy clusters are the best indirect detection target for a neutrino telescope like IceCube -- this has been recently confirmed by the IceCube collaboration. Additionally I will also show how meson decay or W decay can constrain certain models of dark matter which have been proposed recently to solve all small-scale structure problems in LambdaCDM cosmology.
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Reanalysis of the Reactor Neutrino Anomaly
- Time: 2:30 pm
- Place: 4274 Chamberlin Hall
- Speaker: Anna Hayes-Sterbenz, Los Alamos National Laboratory
- Abstract: Recent analyses of the anti-neutrino flux from reactors has suggested that shot baseline reactor neutrino experiments saw only about 92.7% of the expected flux, a result is commonly referred to as the Reactor Neutrino Anomaly. In this talk I will present an independent analysis of this anomaly and the underlying nuclear physics determining the shape and magnitude of reactor neutrino spectra. In this analysis, we find that corrections due to forbidden beta-decays of fission fragments result in significant changes to the shape of the spectrum. These changes, which have not been taken into account in earlier anomaly analyses, leads to more anti-neutrinos being emitted at low (<2.5 MeV) and high energies (>4.5 MeV), and fewer anti-neutrinos between 2.5-4.5 MeV. The uncertainty in the shape of the spectrum also increases when the forbidden transitions are included. The measured spectrum from the near detector at Daya Bay should greatly help to reduce these uncertainties.
- Host: Karsten Heeger