2019 Fall Graduate Colloquium Series: Alexandria Mendoza/Robby Vukelich

DateOctober 18, 2019Time3:35 - 5:00 pm
LocationBaylor Sciences Building, Room E.125
2019 Fall Graduate Colloquium Series

Alexandria Mendoza
Dynamics of Nonspherical, Fractal-Like Water-Ice Particles in a Plasma Environment

Plasmas containing small solid-state particles (also known as dust particles) are ubiquitous in nature and laboratories. Existing models typically assume that the dust particles are spherical but several observations and simulations indicate that a significant amount of dust particles are nonspherical. Because dust particles are not spherical they show different dynamics from spherical particles in a plasma environment namely, they align in the direction perpendicular to the force equilibrium line, rotate about their alignment axis due to the interaction between the dipole moment and the surrounding electric field, and show vortex motion while maintaining their alignment and rotation when they are exposed to a nonconservative drag force.


Robby Vukelich

A Measurement of the Atomic Hydrogen Lamb shift and the Proton Charge Radius

Previous measurements of the proton charge radius by the average of high-resolution spectroscopy of atomic hydrogen and elastic scattering of electrons compared to the muonic hydrogen Lamb shift differed by ~4%. Over the past decade, scientists have attempted to determine the source of the discrepancy found by the two different methods, also known as the proton radius puzzle. A recent measurement of the atomic hydrogen Lamb shift has shown the proton charge radius to agree with that found from the muonic hydrogen Lamb shift but not that of the averaged value.

N. Bezginov et al.
DOI: 10.1126/science.aau7807
Science 365 (6457), 1007-1012.

For more information contact: Dr. Kenneth Park 254-710-2282
PublisherDepartment of Physics
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