${{\mathit t}}$-quark Polarization in ${{\mathit t}}{{\overline{\mathit t}}}$ Events in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV

INSPIRE   PDGID:
Q007PL7
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.
VALUE DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$-0.035$ $\pm0.014$ $\pm0.037$ 1
AAD
2013BE
 ATLS A$_{CPC}$
$0.020$ $\pm0.016$ ${}^{+0.013}_{-0.017}$ 1
AAD
2013BE
 ATLS A$_{CPV}$
1  Based on 4.7 fb${}^{-1}$ of data using the final states containing one or two isolated electrons or muons and jets with at least one ${{\mathit b}}$-tag.
References