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Dijet invariant mass distribution, $m_{jj}$, for $\Wboson$ boson candidates (left) and three-jet invariant mass, $m_{jjj}$, for top quark candidates (right) in data compared to the sum of $\ttbar$ simulation and multi-jet background. The ratio comparing data to prediction is shown below each distribution. The hatched bands reflect the sum of the statistical and systematic errors added in quadrature. The $\ttbar$ simulation corresponds to $\mtop = 172.5\,\textrm{GeV}$.

Dijet invariant mass distribution, $m_{jj}$, for $\Wboson$ boson candidates (left) and three-jet invariant mass, $m_{jjj}$, for top quark candidates (right) in data compared to the sum of $\ttbar$ simulation and multi-jet background. The ratio comparing data to prediction is shown below each distribution. The hatched bands reflect the sum of the statistical and systematic errors added in quadrature. The $\ttbar$ simulation corresponds to $\mtop = 172.5\,\textrm{GeV}$.

$\rtt$ distribution as obtained after applying the analysis event selection shown together with the expected sum of $\ttbar$ simulation and multi-jet background. The distribution is shown before the $\chi^2$ fit is applied. The ratio comparing data to prediction is shown below the figure. The hatched bands reflect the sum of the statistical and systematic errors added in quadrature. The $\ttbar$ simulation corresponds to $\mtop = 172.5\,\textrm{GeV}$.

Templates for the $\rtt$ distributions for $\ttbar$ MC samples generated at $\mtop$ values of $167.5$, $172.5$, and $177.5\,\textrm{GeV}$, respectively. Results from the combined, simultaneous fit to all five $\rtt$ distributions are superimposed (black line with blue filled area). For each distribution it consists of a Novosibirsk function (red line) describing the signal part and a Landau function (green dashed-line) describing the combinatorial background part. Their parameters are assumed to depend linearly on $\mtop$. The $\chi^2$ per degree of freedom obtained for each of the three template distribution corresponds to $1.22$, $3.98$, and $1.96$ respectively. The plot under each distribution shows the residuals obtained from calculating the difference between the combined fit and the simulated $\rtt$ distribution normalised to the statistical uncertainty for each bin individually.

Templates for the $\rtt$ distributions for $\ttbar$ MC samples generated at $\mtop$ values of $167.5$, $172.5$, and $177.5\,\textrm{GeV}$, respectively. Results from the combined, simultaneous fit to all five $\rtt$ distributions are superimposed (black line with blue filled area). For each distribution it consists of a Novosibirsk function (red line) describing the signal part and a Landau function (green dashed-line) describing the combinatorial background part. Their parameters are assumed to depend linearly on $\mtop$. The $\chi^2$ per degree of freedom obtained for each of the three template distribution corresponds to $1.22$, $3.98$, and $1.96$ respectively. The plot under each distribution shows the residuals obtained from calculating the difference between the combined fit and the simulated $\rtt$ distribution normalised to the statistical uncertainty for each bin individually.

Templates for the $\rtt$ distributions for $\ttbar$ MC samples generated at $\mtop$ values of $167.5$, $172.5$, and $177.5\,\textrm{GeV}$, respectively. Results from the combined, simultaneous fit to all five $\rtt$ distributions are superimposed (black line with blue filled area). For each distribution it consists of a Novosibirsk function (red line) describing the signal part and a Landau function (green dashed-line) describing the combinatorial background part. Their parameters are assumed to depend linearly on $\mtop$. The $\chi^2$ per degree of freedom obtained for each of the three template distribution corresponds to $1.22$, $3.98$, and $1.96$ respectively. The plot under each distribution shows the residuals obtained from calculating the difference between the combined fit and the simulated $\rtt$ distribution normalised to the statistical uncertainty for each bin individually.

Template distributions shown simultaneously for three separate input values of $\mtop$ ($167.5$, $172.5$, and $177.5\,\textrm{GeV}$), highlighting the sensitivity of the $\rtt$ shape to $\mtop$. The plot under the distribution shows the ratio of $\mtop$ at $167.5$, and $177.5\,\textrm{GeV}$ to $\mtop$ at $172.5\,\textrm{GeV}$.

The difference mean, $\left(\mtop^{\textrm{meas}}-\mtop^{\textrm{gen}}\right)$, based on the results of a fit to a single Gaussian function. The black markers correspond to cases where the pseudo events were drawn from the $\rtt$ histograms, and the open marker points where pseudo events were drawn from the parameterisations. The solid blue line corresponds to a polynomial fit to the five black markers and their corrected uncertainties.

The left plot shows the $\rtt$ distribution in data with the total fit (in magenta) and its decomposition into signal (in red) and the multi-jet background (in blue). The errors shown are statistical only. The right plot shows the ellipses corresponding to the $1$-$\sigma$ (solid line) and $2$-$\sigma$ (dashed line) statistical uncertainty. The central point in the figure indicates the values obtained for $\mtop$ on the $x$--axis, and the fitted background fraction, $\fbkgd$, obtained within the fit range of the $\rtt$ distribution on the $y$--axis. The plots do not take into account the small bias correction described in Section~\ref{sec:systematics_nonclosure}. The top-quark mass, after this correction, is $173.72 \pm 0.55 \stat \pm 1.01 \syst \,\textrm{GeV}$.

The left plot shows the $\rtt$ distribution in data with the total fit (in magenta) and its decomposition into signal (in red) and the multi-jet background (in blue). The errors shown are statistical only. The right plot shows the ellipses corresponding to the $1$-$\sigma$ (solid line) and $2$-$\sigma$ (dashed line) statistical uncertainty. The central point in the figure indicates the values obtained for $\mtop$ on the $x$--axis, and the fitted background fraction, $\fbkgd$, obtained within the fit range of the $\rtt$ distribution on the $y$--axis. The plots do not take into account the small bias correction described in Section~\ref{sec:systematics_nonclosure}. The top-quark mass, after this correction, is $173.72 \pm 0.55 \stat \pm 1.01 \syst \,\textrm{GeV}$.