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L/T separated cross sections and beam asymmetries in kaon electroproduction above the resonance region

ORAL

Abstract

The 12 GeV JLab beam energy and the new Super-High Momentum Spectrometer (SHMS) in Hall C have enabled measurements of precision longitudinal-transverse separated cross sections in exclusive $K^+$ production from the proton above the resonance region. The data acquired by experiment E12-09-011, and the anticipated L/T separated cross sections will be an important step forward in understanding the nonperturbative structure of hadrons including strangeness and the transition from hadronic to partonic degrees of freedom in exclusive processes. Kaons were detected in the SHMS in coincidence with scattered electrons in the HMS. Kaon-proton separation was provided by a threshold aerogel detector and kaon-pion separation by a gas Cherenkov detector. Data were taken in near-parallel kinematics at two electron beam energies. Fitting the azimuthal angle dependence of the measured unpolarized cross section allows for a full separation of the structure functions $\sigma_L$, $\sigma_T$,$\sigma_{LT}$ and $\sigma_{TT}$ . The beam single spin asymmetry from a longitudinally polarized beam leads to a fifth structure function $\sigma_{\mathrm{LT}^{'}}$ . Kaon and pion asymmetries were acquired at ${Q^2}=3.0$, W=2.32, x=0.40. I will give an overview of the experiment and show initial results.

Authors

  • Mireille Muhoza

    The Catholic University of America

  • Richard Trotta

    The Catholic University of America