Events at Physics |
Events on Friday, November 13th, 2009
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Lepton) Flavor Violation in SUSY GUT and Randall-Sundrum Models
- Time: 2:30 pm
- Place: 2301 Sterling Hall
- Speaker: Mu-Chun Chen, U. C. Irvine
- Abstract: In the first part of this talk, I will discuss theoretical predictions of various SUSY GUT models for lepton flavor violation. Including the WMAP dark matter constraints, lower bounds on the branch fractions of these LFV rare charged lepton decays can be obtained. Furthermore, a next generation MECO-like experiment turns out to be the more robust way in distinguishing various GUT models.<br>
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In the second part of the talk, I will focus on flavor violation in RS models. Generically, RS models suffer from strong constraints due to the presence of the FCNCs at tree-level. Furthermore, these models require fine tuning in order to get large neutrino mixing. I will present a model based on the double tetrahedral family symmetry which successfully avoids the tree-level FCNCs in both quark and lepton sectors. In addition, our model gives rise to realistic masses and mixing angles for both quarks and leptons. - Host: Michael Ramsey-Musolf
- Physics Department Colloquium
- Inward Turbulent Diffusion of Plasmas in a Levitated Dipole
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Michael Mauel, Columbia University
- Abstract: The rearrangement of plasma due to turbulence is among the most important processes that occur in planetary magnetospheres and in experiments used for fusion energy research. Remarkably, fluctuations that occur in active magnetospheres drive particles inward and create centrally peaked profiles. Until now, the strong peaking seen in space has been undetectable in the laboratory because the loss of particles along the magnetic field is faster than the net driven flow across the magnetic field. Here, we report the first laboratory measurements in which a strong superconducting magnet is levitated and used to confine high temperature plasma in a configuration that resembles planetary magnetospheres. Levitation eliminates field-aligned particle loss, and the central plasma density increases dramatically. The buildup of density characterizes a turbulent pinch and is found equal to the rate predicted from measured electric field fluctuations. Our observations show that dynamic principles describing magnetospheric plasma are relevant to plasma confined by a levitated dipole.
- Host: Forest