${{\boldsymbol t}}$-quark Polarization in ${{\boldsymbol t}}{{\overline{\boldsymbol t}}}$ Events in ${{\boldsymbol p}}{{\boldsymbol p}}$ Collisions at $\sqrt {s }$ = 7 TeV
INSPIRE search
The double differential distribution in polar angles, ${{\mathit \theta}_{{1}}}$ (${{\mathit \theta}_{{2}}}$) of the decay particle of the top (anti-top) decay products, is parametrized as (1/${{\mathit \sigma}}$)d${{\mathit \sigma}}$/(dcos ${{\mathit \theta}_{{1}}}$ dcos ${{\mathit \theta}_{{2}}}$) = (1/4) ( 1 + A$_{t}$ cos ${{\mathit \theta}_{{1}}}$ + A$_{{{\overline{\mathit t}}}}$ cos ${{\mathit \theta}_{{2}}}$ $−$ C cos ${{\mathit \theta}_{{1}}}$ cos ${{\mathit \theta}_{{2}}}$ ). The charged lepton is used to tag ${{\mathit t}}$ or ${{\overline{\mathit t}}}$. The coefficient A$_{t}$ and A$_{{{\overline{\mathit t}}}}$ measure the average helicity of ${{\mathit t}}$ and ${{\overline{\mathit t}}}$, respectively. A$_{CPC}$ = A$_{t}$ = A$_{{{\overline{\mathit t}}}}$ assumes $\mathit CP$ conservation, whereas A$_{CPV}$ = A$_{t}$ = $−A_{{{\overline{\mathit t}}}}$ corresponds to maximal $\mathit CP$ violation.
