JILA Auditorium

**Special Physics Colloquium** — "Towards Precision Accelerator Based Neutrino Physics"

The Deep Underground Neutrino Experiment (DUNE) is an experiment under construction that will use a neutrino beam created at Fermilab in Illinois and sent through the earth to a very large detector in the Homestake mine in South Dakota. DUNE will attack many of the interesting outstanding questions in neutrino physics, and the core of its mission will be a search for CP violation by neutrinos. These measurements will require a neutrino beam of unprecedented intensity and a similarly unprecedented understanding of neutrino interactions with matter. The experiment itself, as well as recent ef

Driving atomic monolayers: From collective light scattering to universal heating dynamics

Ultracold atoms in a single plane of an optical lattice are an ideal system to study many-body phenomena even with single atom resolution. Here we report on two recent studies on this platform, where the atomic system is externally driven, albeit in very different ways. First, we will discuss a monolayer driven by resonant light and the implications of the regular sub-wavelength structure to light scattering. We observed a strongly sub-radiant response and an enhanced back-scattering, showing that a single atomic layer can make an efficient mirror.

New Insights into Plasma Turbulence

Many plasmas of interest – in astrophysical applications, in space, and in the laboratory – exhibit very large Reynolds numbers, implying that they are invariably found to be in a turbulent state. This pervading turbulence thus becomes a critical element in the understanding of phenomena such as energy dissipation, particle acceleration, magnetic field generation and dynamics, transport properties, etc. Because these plasmas are magnetized, theoretical descriptions of plasma turbulence have to take into account the dynamic interaction between the plasma and the magnetic field.

Using Debris Disks to Trace the Dynamics of Planetary Systems

Debris disks are signposts of mature planetary systems, and millimeter-size dust is an excellent tracer of the gravitational landscape around planets. I will describe observations using the Atacama Large Millimeter/Submillimeter Array (ALMA) that leverage the presence of debris disks to explore the dynamics of planetary systems. For example, we can use the vertical puffiness (or lack thereof) to hunt for otherwise invisible Uranus and Neptune analogs, and in systems with directly imaged companions we can use the chaotic zone extent as a measurement of the dynamical mass of the companion.

Reflections from 50 Years of Teaching Astronomy

I’ve had the opportunity to teach astronomy off and on for 50 years. In this colloquium, I’ll describe and share the most valuable, useful, and surprising lessons I’ve learned. Particular emphasis will be on the results of experiments conducted on large numbers of university students and faculty: What can be better than a clear, well-explained, interesting lecture? Is it true that student mistakes are not random (yes) and how should faculty respond to this? What technology increases learning, and what decreases it?

Supermassive Black Hole Outflows and Pairs

Supermassive black holes, once thought to be theoretical novelties, are now considered to play a major role in many astrophysical phenomena including galaxy evolution. Now that we live in the era of gravitational wave observations, it is interesting to look forward to a time when we can detect gravitational waves from supermassive black hole coalescence. A major question remains: Do supermassive black holes merge? I will review the case for supermassive black holes as active players in the universe, focusing on the black hole outflows.

The Terrestrial Planets of Other Stars

For at least the next decade, the only opportunity to study the atmospheres of terrestrial exoplanets will be scrutinize these worlds when they transit nearby small stars. There are 412 mid-to-late M-dwarfs within 15 parsecs, yet we know surprisingly little about them, let alone their attendant planets. I will discuss recent findings from the MEarth Project and TESS Mission, which seek to discover the most spectroscopically accessible terrestrial exoplanets.

Science Results from the Dual Van Allen Probes Mission

A principal goal of the Radiation Belt Storm Probes (RBSP) mission was to develop a much deeper understanding of the structure and dynamics of Earth’s radiation belts. Almost immediately after the late-August 2012 launch of the twin RBSP spacecraft into their highly elliptical orbits, it was discovered that a third Van Allen belt (or “storage ring”) of highly relativistic electrons can exist near the inner part of the traditionally recognized outer Van Allen zone. This feature has been the subject of much theoretical investigation and speculation since its discovery.