Polarization of strange quarks is preserved to a high degree when they
hadronize into Lambda baryons, as observed in Z decays at LEP. This opens up
the possibility for ATLAS and CMS to use strange-quark polarization
measurements as a characterization tool for new physics scenarios that produce
such quarks. Measurements in ttbar samples would be useful for obtaining
additional information about the polarization transfer from the strange quark
to the Lambda baryon. Already with 100/fb in Run 2, ttbar samples in ATLAS and
CMS become competitive in sensitivity with the Z samples of the LEP
experiments. Moreover, while the LEP measurements were done inclusively over
all quark flavors, which makes their interpretation dependent on various
modeling assumptions, ttbar events at the LHC offer multiple handles for
disentangling the different contributions experimentally. We also discuss the
possibility of measuring polarizations of up and down quarks.Comment: 16 pages; v2: minor improvements, published versio