Table 1.

The relative uncertainties in ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}^{\text{vis}}$ and ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}$ and their sources, as obtained from the template fit. The uncertainty in the integrated luminosity and the MC statistical uncertainty are determined separately. The individual uncertainties are given without their correlations, which are however accounted for in the total uncertainties. Extrapolation uncertainties only affect ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}$. For these uncertainties, the ± notation is used if a positive variation produces an increase in ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}$, while the $\mp$ notation is used otherwise

Source	Uncertainty (%)
Trigger	0.3
Lepton ident./isolation	2.0
Muon momentum scale	0.1
Electron momentum scale	0.1
Jet energy scale	0.4
Jet energy resolution	0.4
$\mathrm{b}$ tagging	0.4
Pileup	0.1
$\mathrm{t}\overline{\mathrm{t}}$ ME scale	0.2
$\mathrm{t}\mathrm{W}$ ME scale	0.2
DY ME scale	0.1
PDF	1.1
Top quark $p_{\mathrm{T}}$	0.5
ME/PS matching	0.2
UE tune	0.3
$\mathrm{t}\overline{\mathrm{t}}$ ISR scale	0.4
$\mathrm{t}\mathrm{W}$ ISR scale	0.1
$\mathrm{t}\overline{\mathrm{t}}$ FSR scale	0.8
$\mathrm{t}\mathrm{W}$ FSR scale	0.1
$\mathrm{b}$ quark fragmentation	0.7
$\mathrm{b}$ hadron BF	0.1
Colour reconnection	0.3
DY background	0.9
$\mathrm{t}\mathrm{W}$ background	1.1
Diboson background	0.2
$\mathrm{W}$+jets background	0.2
$\mathrm{t}\overline{\mathrm{t}}$ background	0.2
Statistical	0.2
Integrated luminosity	2.5
MC statistical	1.1
Total ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}^{\text{vis}}$ uncertainty	3.8
Extrapolation uncertainties
$\mathrm{t}\overline{\mathrm{t}}$ ME scale	${\mp }_{0.1}^{0.3}$
PDF	${\pm }_{0.6}^{0.8}$
Top quark $p_{\mathrm{T}}$	${\mp }_{<0.1}^{0.5}$
$\mathrm{t}\overline{\mathrm{t}}$ ISR scale	${\mp }_{<0.1}^{0.1}$
$\mathrm{t}\overline{\mathrm{t}}$ FSR scale	${\pm }_{<0.1}^{0.1}$
UE tune	<0.1
Total ${\sigma }_{\mathrm{t}\overline{\mathrm{t}}}$ uncertainty	4.0