Abstract:
We present the first measurement of $\sigma(gg \to t\bart$)/sigma($p\barp \to t\bart$). We use 0.96 fb-1 of $\sqrts=1.96$ TeV $p\barp$ collision data recorded with the CDF II detector at Fermilab. Using charged particles with low transverse momentum in $t\bart$ events, we find sigma(gg-->$t\bart$)/sigma($p\barp$-->$t\bart$)=0.07\pm 0.14(stat)\pm 0.07(syst), corresponding to a 95% confidence level upper limit of 0.33, in agreement with the standard model next-to-leading-order prediction of 0.15+/-0.05.