Longitudinal Spin Transfer to $\Lambda$ and $\bar\Lambda$ Hyperons Produced in Polarized Proton-Proton Collisions at $\sqrt{s} = 200$ GeV

The longitudinal spin transfer, $D_{LL}$, of $\Lambda$ and $\bar\Lambda$ hyperons in longitudinally polarized proton-proton collisions is sensitive to the polarization of strange quarks and anti-quarks in the polarized proton, as well as polarized fragmentation. The STAR collaboration previously reported $D_{LL}$ from a data sample obtained in 2005 that corresponds to an integrated luminosity of 2 $pb^{-1}$ with 50\% beam polarization. Considerably larger data samples corresponding to 6.5 $pb^{-1}$ and 25 $pb^{-1}$ with beam polarization of 57\% were obtained in 2006 and 2009. The analysis of these data is in progress and is anticipated to widen the kinematic range and considerably improve the precision of the $D_{LL}$ measurements. The status of the analysis will be discussed.