${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}$ Fraction in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96 TeV

VALUE CL% DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$<0.33$ 68 1
 2009 F
CDF ${{\mathit t}}{{\overline{\mathit t}}}$ correlations
$0.07$ $\pm0.14$ $\pm0.07$ 2
 2008 AG
CDF low $p_T$ number of tracks
 1 Based on 955 pb${}^{-1}$. AALTONEN 2009F used differences in the ${{\mathit t}}{{\overline{\mathit t}}}$ production angular distribution and polarization correlation to descriminate between ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}$ and ${{\mathit q}}$ ${{\overline{\mathit q}}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}$ subprocesses. The combination with the result of AALTONEN 2008AG gives $0.07$ ${}^{+0.15}_{-0.07}$.
 2 Result is based on 0.96 fb${}^{-1}$ of data. The contribution of the subprocesses ${{\mathit g}}$ ${{\mathit g}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}$ and ${{\mathit q}}$ ${{\overline{\mathit q}}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}$ is distinguished by using the difference between quark and gluon initiated jets in the number of small $p_T$ (0.3 GeV $<$ $p_T$ $<$ 3 GeV) charged particles in the central region ($\vert \eta \vert$ $<$ 1.1).
References:
 AALTONEN 2009F
PR D79 031101 Measurement of the Fraction of ${\mathit {\mathit t}}{\mathit {\overline{\mathit t}}}$ Production via Gluon-Gluon Fusion in ${{\mathit p}}{{\overline{\mathit p}}}$ Collisions at $\sqrt {s }$ = 1.96$~$TeV
 AALTONEN 2008AG
PR D78 111101 First Measurement of the Fraction of top-Quark Pair Production through gluon-gluon Fusion