Measuring quark polarizations at ATLAS and CMS

Measuring the polarizations of quarks produced in new physics
processes could provide crucial information about the new physics
Lagrangian. The polarizations of heavy quarks (b and c) are expected
to be largely preserved in the lightest baryons they hadronize into,
Lambda_b and Lambda_c, respectively. Furthermore, it is known
experimentally that s-quark polarization is preserved as well, in
Lambda baryons. We propose how ATLAS and CMS can measure polarizations
of b, c and s quarks using certain decays of the corresponding
baryons. For calibrating these measurements, we suggest to use ttbar
and W+c samples. We estimate that the Run 2 dataset will suffice for
measuring the quark polarizations in these samples with precisions of
order 10%.