#### Ratio of the Production Cross Sections of ${{\mathit t}}{{\overline{\mathit t}}}{{\mathit \gamma}}$ to ${{\mathit t}}{{\overline{\mathit t}}}$ at $\sqrt {s }$ = 1.96 TeV

VALUE DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$0.024$ $\pm0.009$ 1
 2011 Z
CDF $\mathit E_{T}({{\mathit \gamma}}$ ) $>$ 10 GeV, $\vert {{\mathit \eta}}$ (${{\mathit \gamma}}$ )$\vert <$1.0
 1 Based on 6.0 fb${}^{-1}$ of data. The error is statistical and systematic combined. Events with lepton + $\not E_T$ + ${}\geq{}$3 jets(${}\geq{}1{{\mathit b}}$ ) with and without central, high $\mathit E_{T}$ photon are measured. The result is consistent with the SM prediction of $0.024$ $\pm0.005$. The absolute production cross section is measured to be $0.18$ $\pm0.08$ fb. The statistical significance is 3.0 standard deviations.
References:
 AALTONEN 2011Z
PR D84 031104 Evidence for ${{\mathit t}}{{\overline{\mathit t}}}{{\mathit \gamma}}$ Production and Measurement of $\sigma _{ {{\mathit t}} {{\overline{\mathit t}}} {{\mathit \gamma}} }/\sigma _{tt}$