  Dual-phase liquid xenon (LXe) detectors lead the direct search for particle
dark matter. Understanding the signal production process of nuclear recoils in
LXe is essential for the interpretation of LXe based dark matter searches. Up
to now, only two experiments have simultaneously measured both the light and
charge yield at different electric fields, neither of which attempted to
evaluate the processes leading to light and charge production. In this letter,
results from a neutron calibration of liquid xenon with simultaneous light and
charge detection are presented for energies from 3-74 keV, at electric fields
of 0.19, 0.49, and 1.02 kV/cm. No significant field dependence of the yields is
observed.
