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BSM PANDEMIC Seminars
BSM PANDEMIC Double Feature - Iftah Galon (RU) & Yikun Wang (UC)
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America/New_York
Description
Speaker: Iftah Galon (Rutgers University)
Title: Synchrotron-Like Radiation Beyond The Standard Model - Hunting for new physics with the Sokolov-Ternov effect
Abstract: Electron and positron beams in storage-rings self-polarize by emitting spin-flipping synchrotron radiation. This process is known as the Sokolov-Ternov effect. If new ultralight particles couple to electrons, their emission in synchrotron-like radiation can flip the electron spin, and therefore modify the characteristic self-polarization time. In this talk, I will present results for the rate of spin-flipping synchrotron-like radiation in several simplified models, and discuss how polarization time measurements from the Swiss-Light-Source, and SPEAR3 set new strong limits on ultralight axial-vectors coupled to electrons.
Speaker: Yikun Wang (University of Chicago)
Title: Nucleation is more than critical
Abstract: Electroweak baryogenesis is an attractive mechanism to generate the baryon asymmetry of the Universe via a strong first order electroweak phase transition. I will show that the phase transition patterns suggested by the vacuum structure at the critical temperatures, at which local minima are degenerate, with those obtained from computing the probability for nucleation via tunneling through the barrier separating local minima, could be very different and the nucleation probability calculation prefers different regions of parameter space for a strong first order electroweak phase transition. As an example of a model exhibiting such behavior, we study the Next-to-Minimal Supersymmetric Standard Model, whose scalar sector contains two SU(2) doublets and one gauge singlet. Such results demonstrate that analyzing only the vacuum structure via the critical temperatures can provide a misleading picture of the phase transition patterns, and, in turn, of the parameter space for certain classes of models suitable for electroweak baryogenesis.
