Over the last 20 years, searches for dark matter above the proton mass have advanced significantly across direct and indirect searches, but sub-GeV dark matter has until recently been comparatively unprobed. In this talk, I will discuss the state of the Sub-GeV direct detection field, and prospects for applying quantum measurement techniques to lowering mass thresholds for new searches with event thresholds at the eV-scale.

Please go here for website and agenda information.

Zoom Link:  https://stanford.zoom.us/j/94678615030?pwd=YmtGUUoyTFhmSkVZYTRDajd1Z0NtUT09

Ph.D. Candidate: Abel Lawrence Peirson V
Research Advisor: Roger W. Romani

Axions are a well-motivated extension to the Standard Model and are among the best candidates to explain dark matter. Their detection is made difficult by the fact that they couple very weakly to particles in the Standard Model. High-energy astrophysical settings host extreme conditions wherein axions may be produced in great abundance. In this talk, I will discuss axion production in the highly magnetized plasma surrounding compact objects, particularly neutron stars. Once produced, axions may re-convert to photons, leading to anomalous emission.

Dark matter can lose energy and become trapped in celestial objects through repeated scatterings against their constituents. If dark matter is asymmetric in nature, there is no sizeable annihilation and therefore large amounts can be accumulated in the interior of stars and planets. Under these conditions, the captured dark matter at the centre grows in mass, eventually becoming unstable and collapsing. This process can lead to a small black hole which, depending on its initial mass, can either evaporate to high energy particles or grow by accretion destroying the host.

The angular resolution of a stellar interferometer, as for a single telescope, becomes better at smaller wavelengths and larger baselines. The goal for ground detectors would then be optical interferometers with baselines as long as the Earth’s diameter. The latter goal has been achieved in radio, but it becomes prohibitive in the optical, as the electromagnetic field oscillates too rapidly to record and analyze directly over km-long baselines.

Zoom Recording

The experimental value the muon g-2 is 4.2 sigma larger than the Standard Model prediction, when the hadronic vacuum polarization contribution (HVP) is determined from the measured R-ratio, and the HVP calculated in lattice QCD significantly exceeds the measured R-ratio value by a similar margin.  A review of existing e+e experiments reveals that the contribution of certain types of hadronic final states would not have been counted, due to the event selection and trigger requirements of experiments to date.

Here are the zoom coordinates for those of you that won't be able to make it in person: click this link, or manually connect via Meeting ID: 930 8017 8736, Password: 000000

Note that this joint seminar replaces Oren's previously announced separate talks at SLAC and SITP in the usual Friday slots.