Table 1.

Number of events, the predicted signal fraction in the data sample, and the selection efficiency for signal after each selection step. The predicted signal fraction is derived from simulation assuming a $\text{t}\overline{\mathrm{t}}$ cross section of 163 pb [23] and a top-quark mass of 172.5 GeV

Selection step	Events	Sig. frac.	Sel. eff. for
		(%)	signal (%)
At least 6 jets	786,741	3	3.48
At least two b tags	26,304	17	0.91
$P_{\mathrm{gof}}>0.09$	3,691	39	0.30
$\mathrm{\Delta }{R}_{\mathrm{b}\overline{\mathrm{b}}}$	2,418	51	0.25