1. Particle Physics Seminar

    "Cross section measurements by the radiative return method at Belle"

    Presented by Jason D. Crnkovic, University of Washington, Seattle

    Thursday, February 13, 2014, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: Vladimir Tishchenko

    The Belle experiment has produced exclusive cross-section measurements of electron-positron annihilation to hadronic final-states via the radiative return method. Although the Belle detector was designed to study CP-violation in B-meson decays, it is a general-purpose detector with a large solid angle coverage that allows for cross-section measurements. The Belle experiment has taken data at different energies, but was primarily operated as a fixed energy experiment with a CMS energy corresponding to the Upsilon-4S resonance. The radiative return method allows for cross-section measurements to be made over a range of energy bins using a dataset collected at a fixed energy. The Belle dataset provides an opportunity to systematically measure low-energy (3 GeV or less) exclusive hadronic final-state cross-sections. These low-energy cross-sections are used in the Standard Model calculation of the leading-order Hadronic Vacuum Polarization contribution to the muon anomalous magnetic moment and the running of alpha. This presentation will focus on the Belle cross-section measurement of electron-positron annihilation to the three-pion final-state via the radiative return method.