partitioning.[]{data-label="fig:top_Dalitz"}](figure_1a)

![Dalitz distributions for the decay $t \rightarrow W b$ with (left) and without (right) the POWHEG style correction. The black outline indicates the physically allowed region of phase space. In the conventional parton shower approach, the region above the green dashed line is populated with radiation from the bottom quark and the regions below the blue dotted lines with radiation from the top quark. These boundaries correspond to the limits of the parton shower with symmetric phase space partitioning.[]{data-label="fig:top_Dalitz"}](figure_1b)

![Comparison of distributions generated using the standalone parton shower with those generated using a matrix element or POWHEG style correction to the decay $t \rightarrow W b$. Parton level $e^+e^- \rightarrow t \bar{t}$ events were generated at $\sqrt{s}=360 {\,\mathrm{GeV}}$. The left-hand plot shows the distribution of the minimum jet separation, $\Delta R$, and the right-hand plot the logarithm of the jet measure, $y_{32}$. []{data-label="fig:top_parton"}](figure_2a)

![Comparison of distributions generated using the standalone parton shower with those generated using a matrix element or POWHEG style correction to the decay $t \rightarrow W b$. Parton level $e^+e^- \rightarrow t \bar{t}$ events were generated at $\sqrt{s}=360 {\,\mathrm{GeV}}$. The left-hand plot shows the distribution of the minimum jet separation, $\Delta R$, and the right-hand plot 