Longitudinal Spin Transfer of $\Lambda$ and $\bar\Lambda$ 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, and 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. In 2006 and 2009 larger data samples were obtained, corresponding to 8.5 $pb^{-1}$ and 25 $pb^{-1}$ with beam polarizations of 53\% and 57\%, respectively. These data are expected to considerably improve the precision of the $D_{LL}$ measurement and extend their range to larger transverse momenta, $p_{T}$. Increased acceptance of jet triggered events in 2009 are expected to enhance the sample of $\Lambda$ and $\bar\Lambda$ hyperons associated to jets. The analysis status will be discussed.