The radiative decay width measurement of the η-meson at GlueX

ORAL

Abstract

The PrimEx-eta experiment at Jefferson Lab is aiming to measure the radiative decay width of the η-meson via the Primakoff effect. It will provide a critical input to determine the η-η′ mixing angle and the light quark mass ratio model-independently. Three runs were performed with the GlueX experimental setup in Hall D in 2019, 2021, and 2022. We will discuss the status of experiment and how the radiative decay width is extracted from the η-meson photoproduction off a helium nucleus. We will also discuss the measurement of Compton scattering off an atomic electron, which is used to control experimental systematics, including the detection efficiency, the luminosity, and the measurement stability overtime.

*This work was partially supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contracts DE-SC0013620 and DE-AC05-06OR23177, and NSF awards PHY-1812396 and PHY-2111181.

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Presenters

  • Joerg Reinhold

    • Florida International University

Authors

  • Joerg Reinhold

    • Florida International University

  • Liping Gan

    • University of North Carolina Wilmington

  • Igal Jaegle

    • Jefferson Lab

  • Ashot Gasparian

    • North Carolina A&T State University

  • Alexander Somov

    • Jefferson Lab/Jefferson Science Associate

  • Andrew P Smith

    • Duke University