October 16, 2006 (Monday) Srikanth Raghavendra, India
November 13, 2006 (Monday) Tuhin Roy, Boston
November 20, 2006 (Monday) Dave Soper, University of Oregon
November 27, 2006 (Monday) Marusa Bradac, KIPAC Institute, SLAC
Neutrino oscillation data suggest that mixing pattern in the lepton sector is bi-large. We have tried to understand this pattern in some specific supersymmetric models where we have considered the possibility of lepton number violaiton by both even and odd number of units. We propose an array of gauge singlet hidden sector superfields and three right-chiral neutrino superfields. We generate neutrino masses by proposing non-renormalizable interactions in the leptonic sector. We have also proposed a supergravity model by having a hidden sector superfield carrying lepton number. We suggest specific forms of the superpotential and the Kahler potential, which can give ? L = 2 terms in the low-energy regime but no ? L = 1 term, thereby making the lightest supersymmetric particle to be a candiate for dark matter.
4:00 pm, 472 Willamette Hall
Refreshments served at 3:45
Refreshments served at 3:45
Refreshments served at 3:45
The cluster of galaxies 1E0657-56 has been the subject of intense ongoing research in the last few years. This system is remarkably well-suited to addressing outstanding issues in both cosmology and fundamental physics. It is one of the hottest and most luminous X-ray clusters known and is unique in being a major supersonic cluster merger occurring nearly in the plane of the sky, earning it the nickname "the Bullet Cluster". In this talk I will present our measurements of the composition of this system, show the evidence for existence of dark matter, and describe limits that can be placed on the intrinsic properties of dark matter particles. In addition, I will explain how this cluster offers a serious challenge to MOdified Newtonian Dynamics (MOND) theories.
4:00 pm, 472 Willamette Hall
Refreshments served at 3:45