CERN Accelerating science

Invariant mass of the \gamjet\ pair for events passing the final selections. The bin widths are chosen to be twice the mass resolution at the centre of each bin. Overlaid is the fitted background function integrated over each bin (solid line), with three examples of \qstar signals, as described in the text. For better visibility the \qstar signals are only drawn for \Mgj{} within $\pm$25\% of the nominal signal mass. The bottom panel shows the statistical significance of the difference between data and background in each bin.

The 95\% CL upper limits on $\sigma\times BR\times A\times \varepsilon$ for a hypothetical signal with a Gaussian-shaped $m_{\gamma j}$ distribution as a function of the signal mass $m_\mathrm{G}$ for four values of the relative width $\sigma_\mathrm{G}/m_\mathrm{G}$.

The 95\% CL upper limits on $\sigma \times BR\times A\times \varepsilon$ for QBHs decaying to a photon and a jet, as a function of the threshold mass $M_\mathrm{th}$, assuming $M_{D} = M_\mathrm{th}$ and $n=6$. The limits take into account statistical and systematic uncertainties. Points along the solid black line indicate the mass of the signal where the limit is computed. The black short dashed line is the central value of the expected limit. Also shown are the $\pm 1\sigma$ and $\pm 2\sigma$ uncertainty bands indicating the underlying distribution of possible limit outcomes under the background-only hypothesis. The predicted visible cross-section for QBHs is shown as the long dashed line.

The 95\% CL upper limits on $\sigma \times BR\times A\times \varepsilon$ for excited quarks decaying to a photon and a jet, as a function of the signal mass $m_{q^*}$. The limits take into account statistical and systematic uncertainties. Points along the solid black line indicate the mass of the signal where the limit is computed. The black short dashed line is the central value of the expected limit. Also shown are the $\pm 1\sigma$ and $\pm 2\sigma$ uncertainty bands indicating the underlying distribution of possible limit outcomes under the background-only hypothesis. The long dashed line shows the predicted visible cross-section for excited-quark production from \pythia.