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| CMS-PAS-SUS-16-047 | ||
| Search for supersymmetry in events with at least one photon, missing transverse momentum, and large transverse event activity in proton-proton collisions at 13 TeV | ||
| CMS Collaboration | ||
| March 2017 | ||
| Abstract: A search for physics beyond the standard model in final states with at least one photon, large transverse momentum imbalance, and large total transverse event activity is presented. This event selection provides good sensitivity for gauge mediated supersymmetry models in which pair-produced gluinos or squarks decay via short-living neutralinos to photons and gravitinos. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ of proton-proton collisions recorded by the CMS experiment at the LHC in 2016. No excess of events above the standard model background is observed. The data is interpreted in simplified models of gluino- and squark pair production, in which gluinos and squarks decay via gauginos to photons. Gluino masses of up to 2 TeV and squark masses up to 1.6 TeV are excluded. | ||
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Links:
CDS record (PDF) ;
inSPIRE record ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, JHEP 12 (2017) 142. The superseded preliminary plots can be found here. |
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| Figures & Tables | Summary | Additional Figures | References | CMS Publications |
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Additional information on efficiencies needed for reinterpretation of these results are available here. Additional technical material for CMS speakers can be found here. |
| Figures | |
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Figure 1:
Feynman diagrams for simulated signal processes: T6gg (top left), T6Wg (top right), T5gg (bottom left) and T5Wg (bottom right). |
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Figure 1-a:
Feynman diagrams for simulated signal processes T6gg. |
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Figure 1-b:
Feynman diagrams for simulated signal processes T6Wg. |
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Figure 1-c:
Feynman diagrams for simulated signal processes T5gg. |
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Figure 1-d:
Feynman diagrams for simulated signal processes T5Wg. |
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Figure 2:
Validation of the non-genuine ${ {p_{\mathrm {T}}} ^\text {miss}}$ background estimation method with $\gamma$+jets and multijet simulations. The low-$EM{H_{\mathrm {T}}} $ selection is shown on the left, the high-$EM{H_{\mathrm {T}}} $ selection on the right. |
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Figure 2-a:
Validation of the non-genuine ${ {p_{\mathrm {T}}} ^\text {miss}}$ background estimation method with $\gamma$+jets and multijet simulations. The low-$EM{H_{\mathrm {T}}} $ selection is shown. |
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Figure 2-b:
Validation of the non-genuine ${ {p_{\mathrm {T}}} ^\text {miss}}$ background estimation method with $\gamma$+jets and multijet simulations. The high-$EM{H_{\mathrm {T}}} $ selection is shown. |
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Figure 3:
Validation of the background estimation method for electrons misreconstructed as photons, using W and $ {\mathrm{ t } {}\mathrm{ \bar{t} } } $ simulation. The low-(high-)$EM{H_{\mathrm {T}}} $ selection is shown on the left (right). |
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Figure 3-a:
Validation of the background estimation method for electrons misreconstructed as photons, using W and $ {\mathrm{ t } {}\mathrm{ \bar{t} } } $ simulation. The low-$EM{H_{\mathrm {T}}} $ selection is shown. |
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Figure 3-b:
Validation of the background estimation method for electrons misreconstructed as photons, using W and $ {\mathrm{ t } {}\mathrm{ \bar{t} } } $ simulation. The high-$EM{H_{\mathrm {T}}} $ selection is shown. |
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Figure 4:
Validation of the background estimation methods with photons reconsructed in the endcap. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The low-(high-)$EM{H_{\mathrm {T}}} $ selection is shown on the left (right). Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distributions, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 4-a:
Validation of the background estimation methods with photons reconsructed in the endcap. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The low-$EM{H_{\mathrm {T}}} $ selection is shown. Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distribution, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 4-b:
Validation of the background estimation methods with photons reconsructed in the endcap. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The high-$EM{H_{\mathrm {T}}} $ selection is shown. Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distribution, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 5:
Observed data compared to the background prediction. Two signal models are shown added to the background. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The low-(high-)$EM{H_{\mathrm {T}}} $ selection is shown on the left (right). Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distributions, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 5-a:
Observed data compared to the background prediction. Two signal models are shown added to the background. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The low-$EM{H_{\mathrm {T}}} $ selection is shown. Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distribution, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 5-b:
Observed data compared to the background prediction. Two signal models are shown added to the background. The expectation for the T5Wg signal scenario with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV and the T6gg signal scenario with a squark mass of 1750 GeV and a neutralino mass of 1650 GeV are shown added to the background. The high-$EM{H_{\mathrm {T}}} $ selection is shown. Below the $ { {p_{\mathrm {T}}} ^\text {miss}} $ distribution, the data divided by the background prediction are shown as black dots, and the relative background components are shown as colored areas. |
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Figure 6:
Exclusion limits at 95% CL for T6gg (top left) T6Wg (top right), T5gg (bottom left) and T5Wg (bottom right) models. The solid black curve represents the observed exclusion contour and the uncertainty due to the signal cross section. The red dashed curves represent the expected exclusion contours and the experimental uncertainties. |
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Figure 6-a:
Exclusion limits at 95% CL for the T6gg model. The solid black curve represents the observed exclusion contour and the uncertainty due to the signal cross section. The red dashed curves represent the expected exclusion contours and the experimental uncertainties. |
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Figure 6-b:
Exclusion limits at 95% CL for the T6Wg model. The solid black curve represents the observed exclusion contour and the uncertainty due to the signal cross section. The red dashed curves represent the expected exclusion contours and the experimental uncertainties. |
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Figure 6-c:
Exclusion limits at 95% CL for the T5gg model. The solid black curve represents the observed exclusion contour and the uncertainty due to the signal cross section. The red dashed curves represent the expected exclusion contours and the experimental uncertainties. |
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Figure 6-d:
Exclusion limits at 95% CL for the T5Wg model. The solid black curve represents the observed exclusion contour and the uncertainty due to the signal cross section. The red dashed curves represent the expected exclusion contours and the experimental uncertainties. |
| Tables | |
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Table 1:
Observed data compared to the background prediction and the expected signal yields for the T5Wg model with $m_{\tilde{g}}= $ 1600 GeV and $m_{gaugino}=$ 100 GeV. The quadratic sum of statistical and systematical uncertainties are given. Only experimental uncertainties for the signal model are stated. |
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Table 2:
Systematic uncertainties for data-driven backgrounds (first two rows) and simulation (all other rows). If two values are given, the first one is for SM simulation, while the latter is for signal simulation. The PDF and scale uncertainty for signal simulation is for the shape only, as the uncertainty on the rate is considered by [34]. |
| Summary |
| A search for physics beyond the standard model in final states with at least one photon, transverse momentum imbalance, and total transverse event activity has been presented using data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ of proton-proton collisions recorded by the CMS experiment at the LHC in 2016. The SM background is estimated from data and simulation, and is validated in several control regions. No signs of new physics beyond the SM are found, and the data are interpreted in simplified models motivated by GMSB. Gluino masses up to 2 TeV and squark masses up to 1.6 TeV are excluded. |
| Additional Figures | |
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Additional Figure 1:
Covariance between the search regions. |
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Additional Figure 2:
Correlation between the search regions. |
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Additional Figure 3:
Observed significance for T6gg model. |
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Additional Figure 4:
Observed significance for T6Wg model. |
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Additional Figure 5:
Observed significance for T5gg model. |
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Additional Figure 6:
Observed significance for T5Wg model. |
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Additional Figure 7:
Signal yield after several analysis cuts for the T6Wg model with a gluino mass of 1600 GeV and a gaugino mass of 100 GeV. The number of events which would have been produced in the collisions is given in the first bin. The second bin contains events, in which a reconstructed photon with the criteria defined in the analysis is reconstructed. The third bin contains events which have $ EM {H_{\mathrm {T}}} > $ 700 GeV in addition to a photon. In nearly all events of this model, $EM {H_{\mathrm {T}}} $ exceeds 700 GeV. The fourth bin contains events with a reconstructed photon, $ EM {H_{\mathrm {T}}} > $ 700 GeV, and $|\Delta \phi (\pm { {p_{\mathrm {T}}} ^\text {miss}} , {p_{\mathrm {T}}} ^{\gamma })|> $ 0.3. The last six bins are the event yields in the search regions. |
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Additional Figure 8:
Observed and expected exclusion contours for SUS-16-047 (this analysis) and SUS-16-046 for the T6gg model. |
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Additional Figure 9:
Observed and expected exclusion contours for SUS-16-047 (this analysis) and SUS-16-046 for the T6Wg model. |
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Additional Figure 10:
Observed and expected exclusion contours for SUS-16-047 (this analysis), SUS-16-046, and SUS-16-023 for the T5gg model. |
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Additional Figure 11:
Observed and expected exclusion contours for SUS-16-047 (this analysis) and SUS-16-046 for the T5Wg model. |
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