The Physics & Astronomy Colloquium Series presents Krishna Kumar, of University of Massachusetts, on “Electrons are not Ambidextrous: New Insights from a Subatomic Matter of Fact”, on Friday, March 29, at 4:10 p.m. in Clippinger Labs 194.
Krishna Kumar
Abstract: For over a hundred years, one way with which subatomic forces in Nature have been studied is bombarding relativistic elementary particles on quasi-stationary nuclear matter. The most precise and detailed information on fundamental forces and the size and shapes of atomic nuclei and their constituents have come from using accelerated electron beams. Over the past forty years, significant new discoveries about subatomic matter have been made by exploiting an intrinsic quantum property of elementary particles known as “spin”, which manifests itself as a left- or right-handedness when particles move at relativistic speeds. There is a tiny difference (of order parts per million) between the probabilities for scattering left- and right-handed electrons off subatomic matter, which can be used to gain unique new insights into the size of nuclei, the nature of constituent quarks, and to search for new forces that might have shaped the evolution of the early universe. I will describe the experimental technique to measure the tiny left-right probability difference in electron scattering, report on the nuclear and particle physics implications of recent measurements, and motivate the need for new and more precise experiments.
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