Physics Division Seminar: Results from the Calcium Radius Experiment CREX

  • Physics Division Seminar: Results from the Calcium Radius Experiment CREX
    2021-10-15EDT12:00:00 ~ 2021-10-15EDT13:00:00
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Virtual Physics Division Seminar
Robert Michaels
Jefferson Lab
Results from the Calcium Radius Experiment CREX

Abstract:The Calcium Radius Experiment CREX ran in 2019 - 2020 in Hall A at the Thomas Jefferson National Accelerator Facility (JLab) and the first results will be presented. The experiment measured the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons from a 48Ca nucleus at an energy of 2.18 GeV and a scattering angle of 4.7 degrees. The Z boson that mediates the weak neutral interaction couples mainly to neutrons and provides a clean, model-independent measurement of the RMS radius Rn of the neutron distribution in the nucleus. The asymmetry was measured with an accuracy of 4.2% combined statistical and systematic error. The measurement is a fundamental test of nuclear structure theory and will be compared to ab-initio theoretical calculations and nuclear models. Together with the recent PREX (208Pb) result, CREX provides unique experimental input to pin down the density-dependence of the symmetry energy of neutron-rich nuclear matter, which has impacts on neutron star structure, heavy ion collisions, and atomic parity violation experiments. The experiment involved all aspects of the JLab accelerator, starting at the polarized source, and capitalizes on JLab’s unique strengths for carrying out high-precision parity experiments.

Friday, October 15, 2021
12:00 pm – 1:00pm

Event Date
Scientific Program
Contact Name
Douglas Higinbotham
(757) 269-7851