Last year, the STAR Collaboration at RHIC published the first observation of global hyperon polarization in heavy ion collisions. This polarization may be used to extract rotational substructure of the flow field. The result represented a striking validation of the near-equilibrium hydrodynamic paradigm and established the quark-gluon plasma at RHIC as by far the most vortical fluid in nature. More recent studies quantify the vortical structure systematics to challenge hydro models in detail. In addition to the rotational fluid substructure, hyperon polarization should probe the strong magnetic fields expected in heavy ion collisions. Measuring these fields is crucial for establishing and quantifying the so-called Chiral Magnetic Effect at RHIC. Experimental uncertainties are currently too large to conclusively measure the magnetic field, but detector upgrades at STAR and dedicated running at RHIC may allow a breakthrough in this year's (2018) run.
URL of online video: https://bluejeans.com/s/kWVsE/
It seems like a terrible time to be a scientist in the United States. Federal budgets aren't being passed, and when they are, funding for science never seems to increase. The debate over immigration reform-including what to do about visas for high-skilled workers, such as scientists-is stalled. Everyone agrees that cybersecurity is a problem, but no one seems to have a solution. Meanwhile, we have no meaningful debate in Congress or in the administration on climate change or energy policy. This lecture will cover how we got here, why we are stuck, some speculation on how the current administration is impacting research, and how the scientific community can impact policy.
URL of online video: https://bluejeans.com/s/NPfzO/
URL of online video: https://bluejeans.com/s/jH62H/
In the 50+ years since its discovery, the cosmic microwave background (CMB) has yielded surprisingly detailed and precise information about the form, content and dynamics of the early universe. High angular resolution maps, and polarization data at all angular scales, are the focus of current and next-generation instruments. I will describe what we already know about the universe from the CMB, and lay the ground for future revelations from the CMB, with special emphasis on the Atacama Cosmology Telescope (ACT). ACT is a special-purpose 6m telescope situated at 17,000 ft in the dry Atacama Desert of northern Chile, at a latitude of 23 degrees South. ACT's millimeter-wave detectors measure both polarization and intensity at very fine angular scales (arcminutes). I will describe the ACT instrument and its data in the context of other ongoing and proposed CMB projects, their scientific impact, and the potential discovery space. I will include a brief description of the upcoming Simons Observatory.
URL of online video: https://bluejeans.com/s/fldME/
The Muon g-2 experiment at Fermilab is measuring the anomalous magnetic dipole moment of the muon with an improved factor of four accuracy (140 ppb). The new measurement is inspired by the > 3sigma discrepancy between the Brookhaven experimental measurement and Standard Model prediction, where the discrepancy gives hints of new physics beyond the Standard Model. The Fermilab's Muon g - 2 experiment is taking physics data and is projected to accumulate 1 x BNL statistics by the end of the spring 2018 Fermilab's accelerator shutdown. In this presentation, I will discuss the scientific motivation and physics of muon g - 2 experiments and conclude with a snapshot of data results from the beginning of the physics run.
URL of online video: https://bluejeans.com/s/Oghdn/
Understanding the dynamical behavior of many-particle systems following a deep quench is a central issue in both statistical mechanics and complex systems theory. One of the basic questions centers on the issue of predictability: given a system with a random initial state evolving through a well-defined stochastic dynamics, how much of the information contained in the state at future times depends on the initial condition (``nature'') and how much on the dynamical realization (``nurture'')? We discuss this question and present both old and new results for both homogeneous and random systems in low and high dimension.
URL of online video: https://bluejeans.com/s/8dyf0/
Our universe is immersed in magnetized plasma, electrically conducting ionized gas. Some of the most fundamental and long-standing astrophysical problems, such as the magnetization of the universe, collimation of astrophysical jets, the accretion process and transport in astrophysical disks (surrounding e.g. black holes) and their coronas can only be explored through plasma physics. Our sun as a natural laboratory for plasma physics provides inspiring as well as challenging problems, including its dynamo cycles, heating, and the replication of its core reaction, fusion energy, on earth in a lab. There is an abundance of observational/experimental data emerging from natural phenomena of space and astrophysical plasmas, as well as laboratory plasma experiments, for plasma physicists to explore. I will review some of these topics, in particular magnetic reconnection, the rearrangement of the magnetic field topology of plasmas, which energizes many processes in nature and has been shown to also be critical in the nonlinear dynamics of many processes in toroidal fusion plasmas. Using global simulations, I will demonstrate the instrumental role of magnetic reconnection, which enables an innovative technique for producing current in fusion plasmas.
URL of online video: https://bluejeans.com/s/qPfJq/
A century of coherent experimental and theoretical investigations uncovered the laws of nature that underlie nuclear physics, Quantum Chromodynamics (QCD) and the electroweak interactions. While analytic techniques of quantum field theory have played a key role in understanding the dynamics of matter in high energy processes, they become inapplicable to low-energy nuclear structure and reactions, and dense systems. Expected increases in computational resources into the exascale era will enable Lattice QCD calculations to determine a range of important strong interaction processes directly from QCD. However, important finite density systems, non equilibrium systems, and inelastic processes are expected to remain a challenge for conventional computation. In this presentation, I will discuss the state-of-the-art Lattice QCD calculations, progress that is expected in the near future, and the potential of quantum computing to address Grand Challenge problems in nuclear physics.
URL of online video: https://bluejeans.com/s/bmCRl/
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