Theory Seminars Archive

Thursday, March 24, 2016

Speaker: David Shih

Time: 3:30PM -- 4:30PM

Location: HP4351

Title: Dark Matter, the Higgs and Natural SUSY

Abstract: The natural MSSM is looking increasingly disfavored by the 125 GeV Higgs mass and dark matter direct detection. In this talk, I will present a simple, economical extension of the MSSM that generates the required Higgs mass and includes thermal WIMP dark matter consistent with all existing constraints, all while greatly reducing the fine-tuning. I will discuss prospects for future direct detection experiments and the LHC. 

Thursday, March 10, 2016

Speaker: Eder Izaguirre

Time: 3:30PM -- 4:30PM

Location: HP4351

Title: The vector portal: a window to a dark sector


An emerging paradigm in particle physics is the possibility that new matter resides in its own sector — a Dark Sector (DS) — connected to the Standard Model via a portal. In this talk I will focus on a well-motivated example of such a scenario: the vector portal. I will discuss two distinct phases of the theory. In one, matter in the DS is uncharged under the known forces and is a viable candidate for light Dark Matter. In the other phase of this framework, matter in the DS can instead acquire a non-quantized electromagnetic charge. I will describe proposals for new small-scale experiments to sharply test the different phases of the vector portal.

Thursday, February 25, 2016

Speaker: Matthew Baumgart

Time:  3:30PM -- 4:30PM

Location:  101 PA

Title:   Effective Field Theory of Heavy WIMP Annihilation


We systematically compute the annihilation rate for winos and higgsinos into the final state gamma + X.  The radiative corrections to this process receive enhancement from the large Bloch-Nordsieck-Violating Sudakov logarithm, log(2 M_\chi/M_W).  We resum the double logs and include single logs to fixed order using a formalism that combines nonrelativistic and soft-collinear effective field theories.  For the wino case, we adapt an exclusion curve using results of the HESS experiment.  At the thermal relic mass of 3 TeV, LL' corrections result in a ~30% reduction in rate relative to LL.  Nonetheless, single logs do not save the wino, and it is still excluded by an order of magnitude.  Experimental cuts produce an endpoint region which, our results show, significantly effects the higgsino rate at its thermal relic mass near 1 TeV and is deserving of further study.