CERN Accelerating science

A diagram illustrating the pair production of staus and subsequent decay into a two-$\tau$-lepton final state with missing transverse momentum from the neutralinos.

Illustration of the ABCD method for the multi-jet background determination for SR-lowMass (left) and SR-highMass (right). The control regions A, B, C, and signal region D for the ABCD method described in the text (labeled as CR-A, CR-B, CR-C and SR-lowMass/SR-highMass) are drawn as white boxes. Shown shaded and labeled VR are the regions E and F, which are used to validate the ABCD method and to estimate the systematic uncertainty. The transfer factor \textit{$T$} used in the ABCD method is the ratio of number of multi-jet events in the regions C and B.

Illustration of the ABCD method for the multi-jet background determination for SR-lowMass (left) and SR-highMass (right). The control regions A, B, C, and signal region D for the ABCD method described in the text (labeled as CR-A, CR-B, CR-C and SR-lowMass/SR-highMass) are drawn as white boxes. Shown shaded and labeled VR are the regions E and F, which are used to validate the ABCD method and to estimate the systematic uncertainty. The transfer factor \textit{$T$} used in the ABCD method is the ratio of number of multi-jet events in the regions C and B.

The \mttwo\ (top) and \met (bottom) post-fit distributions in the multi-jet background validation region VR-F (lowMass) at left and VR-F (highMass) at right. The stacked histograms show the contribution of each relevant SM process. The multi-jet shape is taken from VR-E in the ABCD method and the normalization is determined by the transfer factor $T$ and rescaled by a correction factor determined by the background-only fit to data, described in Section \ref{sec:fit}. The hatched bands represent the combined statistical and systematic uncertainties in the sum of the SM backgrounds shown. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines.

The \mttwo\ (top) and \met (bottom) post-fit distributions in the multi-jet background validation region VR-F (lowMass) at left and VR-F (highMass) at right. The stacked histograms show the contribution of each relevant SM process. The multi-jet shape is taken from VR-E in the ABCD method and the normalization is determined by the transfer factor $T$ and rescaled by a correction factor determined by the background-only fit to data, described in Section \ref{sec:fit}. The hatched bands represent the combined statistical and systematic uncertainties in the sum of the SM backgrounds shown. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines.

The \mttwo\ (top) and \met (bottom) post-fit distributions in the multi-jet background validation region VR-F (lowMass) at left and VR-F (highMass) at right. The stacked histograms show the contribution of each relevant SM process. The multi-jet shape is taken from VR-E in the ABCD method and the normalization is determined by the transfer factor $T$ and rescaled by a correction factor determined by the background-only fit to data, described in Section \ref{sec:fit}. The hatched bands represent the combined statistical and systematic uncertainties in the sum of the SM backgrounds shown. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines.

The \mttwo\ (top) and \met (bottom) post-fit distributions in the multi-jet background validation region VR-F (lowMass) at left and VR-F (highMass) at right. The stacked histograms show the contribution of each relevant SM process. The multi-jet shape is taken from VR-E in the ABCD method and the normalization is determined by the transfer factor $T$ and rescaled by a correction factor determined by the background-only fit to data, described in Section \ref{sec:fit}. The hatched bands represent the combined statistical and systematic uncertainties in the sum of the SM backgrounds shown. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines.

The pre-fit \mttwo~distribution in the $W$CR. The SM backgrounds other than multi-jet production are estimated from MC simulation. The multi-jet contribution is estimated from data using the OS--SS method. The hatched bands represent the combined statistical and systematic uncertainties of the total SM background. For illustration, the distributions from the SUSY reference points defined in Section \ref{sec:data} are also shown as dashed lines.

The post-fit yields in the $W$VR, $T$VRs, $Z$VRs and $VV$VRs. The SM backgrounds other than multi-jet production are estimated from MC simulation. The multi-jet contribution is negligible and is estimated from data using the ABCD method, using CRs obtained with the same technique used for the SRs, and described in Section \ref{sec:BG_QCD}. The hatched bands represent the combined statistical and systematic uncertainties of the total SM background. The background-only fit to data is used, described in Section \ref{sec:fit}. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines. The lower panel shows the ratio of data to the SM background estimate.

The post-fit \mttwo\ distribution for SR-lowMass (left) and SR-highMass (right). The stacked histograms show the expected SM backgrounds. The multi-jet contribution is estimated from data using the ABCD method. The contributions of multi-jet and $W$+jets events are scaled with the corresponding normalization factors derived from the background-only fit described in Section \ref{sec:fit}. The hatched bands represent the sum in quadrature of systematic and statistical uncertainties of the total SM background. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines. The last bin includes the overflow events.

The post-fit \mttwo\ distribution for SR-lowMass (left) and SR-highMass (right). The stacked histograms show the expected SM backgrounds. The multi-jet contribution is estimated from data using the ABCD method. The contributions of multi-jet and $W$+jets events are scaled with the corresponding normalization factors derived from the background-only fit described in Section \ref{sec:fit}. The hatched bands represent the sum in quadrature of systematic and statistical uncertainties of the total SM background. For illustration, the distributions from the SUSY reference points (defined in Section \ref{sec:data}) are also shown as dashed lines. The last bin includes the overflow events.

The 95\% CL exclusion contours for the combined fit of SR-lowMass and SR-highMass for simplified models with (a) combined $\stau^{+}_\mathrm{R,L} \stau^{-}_\mathrm{R,L}$ production and (b) $\stau^{+}_\mathrm{L} \stau^{-}_\mathrm{L}$ only production. The text provides details of exclusion curves and uncertainty bands.

The 95\% CL exclusion contours for the combined fit of SR-lowMass and SR-highMass for simplified models with (a) combined $\stau^{+}_\mathrm{R,L} \stau^{-}_\mathrm{R,L}$ production and (b) $\stau^{+}_\mathrm{L} \stau^{-}_\mathrm{L}$ only production. The text provides details of exclusion curves and uncertainty bands.