<p>Joint Theory Seminar Speaker: Tien-Tien Yu (U Oregon)<br />mail: tientien@uoregon.edu<br />Title: Updated BBN Constraints on Ultralight Scalar Dark Matter<br />Host: Verhaaren<br />Room: 432<br />Abstract: Ultralight scalars are an attractive dark matter candidate. <br />We consider the effect of such a dark matter candidate on predictions of Big Bang Nucleosynthesis. As a first study, we look at an ultralight scalar with universal couplings to all massive Standard Model particles. One striking consequence of this new coupling is a change in the predicted abundances of the light elements. In this talk, I will present updated constraints on ultralight scalar dark matter from Helium-4, taking into account the effect of the back-reaction of the Standard Model particles on the dark sector. This effect was neglected in previous works but has noticeable effects. Furthermore, I will present previously uncalculated constraints from deuterium, as well as a comparison to other probes for ultralight scalar dark matter. </p>
<p>Joint Theory Seminar Speaker: Stefania Gori (UC Santa Cruz)<br />mail: stefaniagori83@gmail.com<br />Title: New accelerator experiments for dark sectors<br />Host: Verhaaren<br />Room: 432<br />Abstract: Dark Matter (DM) provides strong evidence for physics beyond the Standard Model (SM). Arguably, rather than suggesting a specific mass scale for New Physics, it may point to a dark sector, weakly-coupled to the SM, as hinted at by the comparable abundances of dark matter and visible baryons. In this seminar, I will discuss new search strategies to broadly probe thermal Dark Matter scenarios at high-intensity accelerator experiments, with a special emphasis on the existing SeaQuest experiment at Fermilab and its possible upgrades. Specifically, I will focus on two interesting thermal dark sector scenarios: a model for inelastic Dark Matter and a model for strongly interacting Dark Matter, and demonstrate the unique capability of the SeaQuest experiment to discover the thermal DM region of these models.</p>
<p>Speaker: Da Liu</p><p>Institution: Argonne National Lab</p><p>Title: Composite Higgs Models at the LHC and beyond</p><p>Host: Markus Luty</p><p>Room: 185</p><p>Abstract: In this talk, I will discuss about the phenomenology of the composite Higgs models at the LHC and future lepton colliders. Spin-1 resonances and the top partners are the smoking gun of the composite Higgs models, their strong interactions will play an important role in the searching for the resonances and cascade decay channels can be important. I will discuss about their prospectives at the HL-LHC and highlight the possibility of left-handed third generation doublet as the massless bound state of the strong sector. In the meanwhile, I will briefly discuss about the universal relationship between the Higgs couplings predicted by the non-linearity and their phenomenological relevance.</p>