Polarized Structure Function $\sigma_{LT'}$ for $p({\vec e},e'K^+)\Lambda$ in the Nucleon Resonance Region

The first measurements of the polarized structure function $$\sigma_{LT'}$$ for the reaction $$p(\vec e,e'K^+)\Lambda$$ in the nucleon resonance region are reported. Measurements are included from threshold up to $W$=2.05 GeV for central values of $Q^2$ of 0.65 and 1.00 GeV$^2$, and nearly the entire kaon center-of-mass angular range. $$\sigma_{LT'}$$ is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate s-channel resonances, as well as resonant and non-resonant processes. The results for $$\sigma_{LT'}$$ are comparable in magnitude to previously reported results from CLAS for $$\sigma_{LT}$$, the real part of the same response. An intriguing sign change in $$\sigma_{LT'}$$ is observed in the high $Q^2$ data at $$W\approx 1.9$$ GeV. Comparisons to several existing model predictions are shown.