Event Category: 4D Seminar

In this talk, I will detail two ways to search for low-mass axion dark matter using cosmic microwave background (CMB) polarization measurements. These appear, in particular, to be some of the most promising ways to directly detect fuzzy dark matter. Axion dark matter causes rotation of the polarization of light passing through it. This gives rise to two novel phenomena … Read More

In this talk, I will present signals from the absorption of fermionic dark matter by nuclear targets at direct detection and neutrino experiments. These signals arise from a set of dimension-6 operators which do not conserve dark matter number and can be broadly classified into “neutral current” and “charged current” varieties. I will present simple UV completions which lead to … Read More

Abstract: In this talk I will describe how causality and the analytic structure of scattering amplitudes impose non-trivial constraints on the standard model effective field theory (SMEFT). In the SMEFT, there are 64 independent operators at mass dimension eight that are quartic in bosons (either Higgs or gauge fields) and that contain four derivatives and/or field strengths, including both CP-conserving … Read More

Abstract: Supernovae can reach temperatures upwards of 30 MeV, allowing them to produce vast quantities of new particles on the MeV scale. In this talk, I will discuss two different models of MeV-scale dark sectors produced in supernovae and their associated direct and indirect signals. Specifically, I will first discuss a model in which dark photons are produced within supernovae … Read More

Abstract: Self-interacting Dark Matter (SIDM) could have a number of striking observable effects, including modifications to the dark matter density on sub-galactic scales. Recent studies have revealed both ultra-compact and ultra-diffuse satellite dwarf galaxies within the Milky Way; I will show that tidal stripping of SIDM satellite halos naturally leads to a wider range of halo density profiles.

There is a great deal of freedom to propose changes from the standard cosmology history of the universe prior to Big Bang Nucleosynthesis. In this talk I will highlight that tweaks to standard cosmology can significantly boost or deplete the expected relic abundance of dark matter. I will highlight some classic applications of these ideas in the context of neutralino … Read More

Abstract: So far, only gravitational signatures of dark matter have been observed. However, in many theories — in particular, all models which could be observed in laboratory experiments — dark matter has extra interactions with the Standard Model and/or itself. In this seminar, I’ll talk about the unusual behaviour that can arise if these interactions are long-ranged. While most computations … Read More

Abstract: Compositeness is an elegant way to address the hierarchy problem. In this talk, I will discuss about the phenomenology of the composite Higgs models at the LHC and beyond, in which Higgs arise as Nambu-Goldstone bosons. Under broad assumption of partial compositeness and symmetry breaking pattern, I will discuss about phenomenology of the spin-1 resonances and the top partners … Read More

Abstract: Direct detection experiments are making tremendous progress in measuring increasingly small energy depositions. As this energy threshold decreases, different excitation channels, such as nuclear recoil, electron transitions, and single phonon excitations, become available. We present a unified theoretical framework for computing direct detection rates via these channels, and expand on previous results in the literature. We derive the in-medium … Read More