Description:

Charles Collett -- “A Variable Path Length Cell for Transverse Acoustic Studies of Superfluid 3He”

Abstract: Bound states on the surface of superfluid 3He-B have recently been shown to be effectively probed using transverse sound. Predicted to be Majorana states in the specular scattering limit, the density of the surface states has been measured using the transverse acoustic impedance, as well as the attenuation of transverse sound in a fixed length cavity. We have developed a variable path length acoustic cell in order to perform in-situ variations of the acoustic path length, which will allow us to more precisely probe the transverse sound attenuation, enabling differentiation between bulk and surface effects. We will also explore cavity lengths down to the micron scale, where detection of transverse sound in the normal state of 3He should be possible.

Kevin Kelly-- “Sterile Neutrinos and CP Violation”

Abstract: Sterile neutrinos are an interesting extension to the standard model, acting as singlet fermions. Unlike "active" neutrinos, they do not interact via the weak force, but may play a role in neutrino oscillations. Several short-baseline experiments have observed anomalies that may be explained by a light sterile neutrino with a new mass splitting of 1 eV^2. Currently proposed experiments aim to observe the effects of a sterile neutrino on the oscillations from electron-type to muon-type neutrinos, and they will potentially confirm the 3 active neutrino + 1 sterile neutrino (3+1) scenario. In this talk, I will outline the framework of neutrino oscillations, including what impact a light sterile neutrino may have, and discuss the 3+1 scenario and the CP Violation that is a result of this extension.

Pizza will be available for $2/slice.