Fig. 6.

Measurements of the $t\overline{t}$ cross-section at $\sqrt{s}=7\mathrm{TeV}$ and $\sqrt{s}=8\mathrm{TeV}$ from this analysis ($e\mathit{\mu }$ $b$-tag) together with previous ATLAS results at $\sqrt{s}=7\mathrm{TeV}$ using the $ee$, $\mathit{\mu }\mathit{\mu }$ and $e\mathit{\mu }$ channels [61] and using a fit to jet multiplicities and missing transverse momentum in the $e\mathit{\mu }$ channel [62]. The uncertainties in $\sqrt{s}$ due to the LHC beam energy uncertainty are displayed as horizontal error bars, and the vertical error bars do not include the corresponding cross-section uncertainties. The three $\sqrt{s}=7\mathrm{TeV}$ measurements are displaced horizontally slightly for clarity. The NNLO+NNLL prediction [6, 7] described in Sect. 2 is also shown as a function of $\sqrt{s}$, for fixed $m_t$ $=172.5\text{GeV}$ and with the uncertainties from PDFs, ${\mathit{\alpha }}_{\mathrm{s}}$ and QCD scale choices indicated by the green band