Date

A search for top-squark pair production, in final states containing a top quark, a charm quark and missing transverse momentum, using the 139 fb$^{-1}$ of $pp$ collision data collected by the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
JHEP 07 (2024) 250, 2024.
Inspire Record 2759516 DOI 10.17182/hepdata.144439

This paper presents a search for top-squark pair production in final states with a top quark, a charm quark and missing transverse momentum. The data were collected with the ATLAS detector during LHC Run 2 and corresponds to an integrated luminosity of 139fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV. The analysis is motivated by an extended Minimal Supersymmetric Standard Model featuring a non-minimal flavour violation in the second- and third-generation squark sector. The top squark in this model has two possible decay modes, either $\tilde{t}_1 \rightarrow c\tilde{\chi}_1^0$ or $\tilde{t}_1\rightarrow t\tilde{\chi}_1^0$, where the $\tilde{\chi}_1^0$ is undetected. The analysis is optimised assuming that both of the decay modes are equally probable, leading to the most likely final state of $tc + E_{\text{T}}^{\text{miss}}$. Good agreement is found between the Standard Model expectation and the data in the search regions. Exclusion limits at 95% CL are obtained in the $m(\tilde{t}_1)$ vs $m(\tilde{\chi}_1^0)$ plane and, in addition, limits on the branching ratio of the $\tilde{t}_1\rightarrow t\tilde{\chi}_1^0$ decay as a function of $m(\tilde{t}_1)$ are also produced. Top-squark masses of up to 800 GeV are excluded for scenarios with light neutralinos, and top-squark masses up to 600 GeV are excluded in scenarios where the neutralino and the top squark are almost mass degenerate.

66 data tables match query

<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>Exclusion contours:</b> <ul> <li><a href="?table=mass_obs">Observed exclusion contour in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=mass_exp">Expected exclusion contour in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=mass_band_1">$\pm1\sigma$ exclusion contour in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=mass_band_2">$\pm1\sigma$ exclusion contour in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=br_m1_obs">Observed exclusion contour in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$</a> <li><a href="?table=br_m1_exp">Expected exclusion contour in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$</a> <li><a href="?table=br_m1_band_1">$\pm1\sigma$ exclusion contour in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$</a> <li><a href="?table=br_m1_band_2">$\pm1\sigma$ exclusion contour in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$</a> </ul> <b>Upper limits:</b> <ul> <li><a href="?table=mass_upperLimits_obs">Observed upper limits on the top-spartner pair production cross-section at the 95% CL in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=br_m1_upperLimits_obs">Observed upper limits on the top-spartner pair production cross-section at the 95% CL in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$.</a> <li><a href="?table=mass_upperLimits_exp">Expected upper limits on the top-spartner pair production cross-section at the 95% CL in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$</a> <li><a href="?table=br_m1_upperLimits_exp">Expected upper limits on the top-spartner pair production cross-section at the 95% CL in the $m_{\tilde{t}_1} - $BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1)$ plane, assuming $m_{\tilde\chi^0_1} = 1 \mathrm{GeV}$.</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=SRA_ntop">SRA region number of top-tagged jets distribution</a> <li><a href="?table=SRA_mttwo">SRA region $m_{\mathrm{T2}}(j^{b}_{R=1.0}, c)$ distribution</a> <li><a href="?table=SRB_ptc">SRB region leading c-tagged jet $p_{\mathrm{T}}$</a> <li><a href="?table=SRB_mtj">SRB region $m_{\mathrm{T}}(j, E_{\mathrm{T}}^{\mathrm{miss}})_{\mathrm{close}}$ distribution</a> <li><a href="?table=SRC_metsig">SRC region missing transverse momentum significance distribution</a> <li><a href="?table=SRC_mtj">SRC region $m_{\mathrm{T}}(j, E_{\mathrm{T}}^{\mathrm{miss}})_{\mathrm{close}}$ distribution</a> <li><a href="?table=SRD_NN">SRD NN signal score distribution</a> <li><a href="?table=SRD_meff">SRD $m_{\mathrm{eff}}$ distribution</a> </ul> <b>Pull distributions:</b> <ul> <li><a href="?table=SRABCPull">Pull plots showing the SRA, SRB and SRC post-fit data and SM agreement using the background-only fit configuration</a> <li><a href="?table=SRDPull">Pull plots showing the SRD post-fit data and SM agreement using the background-only fit configuration</a> </ul> <b>Cut flows:</b> <ul> <li><a href="?table=cutflow_SRA">Cutflow of 3 signal points in the SRA region.</a> <li><a href="?table=cutflow_SRB">Cutflow of 3 signal points in the SRB region.</a> <li><a href="?table=cutflow_SRC">Cutflow of 3 signal points in the SRC region.</a> <li><a href="?table=cutflow_SRD750">Cutflow of 3 signal points in the SRD750 region.</a> <li><a href="?table=cutflow_SRD1000">Cutflow of 3 signal points in the SRD1000 region.</a> <li><a href="?table=cutflow_SRD1250">Cutflow of 3 signal points in the SRD1250 region.</a> <li><a href="?table=cutflow_SRD1500">Cutflow of 3 signal points in the SRD1500 region.</a> <li><a href="?table=cutflow_SRD1750">Cutflow of 3 signal points in the SRD1750 region.</a> <li><a href="?table=cutflow_SRD2000">Cutflow of 3 signal points in the SRD2000 region.</a> </ul> <b>Acceptance and efficiencies:</b> <ul> <li> <b>SRA_bin1:</b> <a href="?table=Acc_SRA_bin1">Acceptance table of the SRA$^{[450,575]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRA_bin1">Efficiency table of the SRA$^{[450,575]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRA_bin2:</b> <a href="?table=Acc_SRA_bin2">Acceptance table of the SRA$^{\geq 575}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRA_bin2">Efficiency table of the SRA$^{\geq 575}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRB_bin1:</b> <a href="?table=Acc_SRB_bin1">Acceptance table of the SRB$^{[100,150]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRB_bin1">Efficiency table of the SRB$^{[100,150]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRB_bin2:</b> <a href="?table=Acc_SRB_bin2">Acceptance table of the SRB$^{[150,400]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRB_bin2">Efficiency table of the SRB$^{[150,400]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRB_bin3:</b> <a href="?table=Acc_SRB_bin3">Acceptance table of the SRB$^{\geq 400}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRB_bin3">Efficiency table of the SRB$^{\geq 400}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRC_bin1:</b> <a href="?table=Acc_SRC_bin1">Acceptance table of the SRC$^{[100,150]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRC_bin1">Efficiency table of the SRC$^{[100,150]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRC_bin2:</b> <a href="?table=Acc_SRC_bin2">Acceptance table of the SRC$^{[150,300]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRC_bin2">Efficiency table of the SRC$^{[150,300]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRC_bin3:</b> <a href="?table=Acc_SRC_bin3">Acceptance table of the SRC$^{[300,500]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRC_bin3">Efficiency table of the SRC$^{[300,500]}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRC_bin4:</b> <a href="?table=Acc_SRC_bin4">Acceptance table of the SRC$^{\geq 500}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRC_bin4">Efficiency table of the SRC$^{\geq 500}$ in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin1:</b> <a href="?table=Acc_SRD_bin1">Acceptance table of the SRD750 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin1">Efficiency table of the SRD750 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin2:</b> <a href="?table=Acc_SRD_bin2">Acceptance table of the SRD1000 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin2">Efficiency table of the SRD1000 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin3:</b> <a href="?table=Acc_SRD_bin3">Acceptance table of the SRD1250 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin3">Efficiency table of the SRD1250 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin4:</b> <a href="?table=Acc_SRD_bin4">Acceptance table of the SRD1500 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin4">Efficiency table of the SRD1500 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin5:</b> <a href="?table=Acc_SRD_bin5">Acceptance table of the SRD1750 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin5">Efficiency table of the SRD1750 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <li> <b>SRD_bin6:</b> <a href="?table=Acc_SRD_bin6">Acceptance table of the SRD2000 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> <a href="?table=Eff_SRD_bin6">Efficiency table of the SRD2000 in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.</a> </ul> <b>Truth Code snippets</b> are available under "Resources" (purple button on the left)

Observed exclusion limits at the 95% CL in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$.

Observed exclusion limits at the 95% CL in the $\tilde{t}_1 - \tilde\chi^0_1$ mass plane, assuming BR$(\tilde{t}_1 \rightarrow t + \tilde\chi^0_1) = 0.5$ and a $+1 \sigma$ deviation of the NNLO+NNLL theoretical cross-section of a $\tilde{t}_1$ pair-production.

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Search for pair-produced higgsinos decaying via Higgs or $Z$ bosons to final states containing a pair of photons and a pair of $b$-jets with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Lett.B 856 (2024) 138938, 2024.
Inspire Record 2773395 DOI 10.17182/hepdata.144072

A search is presented for the pair production of higgsinos $\tilde{\chi}$ in gauge-mediated supersymmetry models, where the lightest neutralinos $\tilde{\chi}_1^0$ decay into a light gravitino $\tilde{G}$ in association with either a Higgs $h$ or a $Z$ boson. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV. It targets final states in which a Higgs boson decays into a photon pair, while the other Higgs or $Z$ boson decays into a $b\bar{b}$ pair, with missing transverse momentum associated with the two gravitinos. Search regions dependent on the amount of missing transverse momentum are defined by the requirements that the diphoton mass should be consistent with the mass of the Higgs boson, and the $b\bar{b}$ mass with the mass of the Higgs or $Z$ boson. The main backgrounds are estimated with data-driven methods using the sidebands of the diphoton mass distribution. No excesses beyond Standard Model expectations are observed and higgsinos with masses up to 320 GeV are excluded, assuming a branching fraction of 100% for $\tilde{\chi}_1^0\rightarrow h\tilde{G}$. This analysis excludes higgsinos with masses of 130 GeV for branching fractions to $h\tilde{G}$ as low as 36%, thus providing complementarity to previous ATLAS searches in final states with multiple leptons or multiple $b$-jets, targeting different decays of the electroweak bosons.

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<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <b>Histograms:</b><ul> <li><a href=?table=Distribution1>Figure 3a: $m_{\gamma\gamma}$ Distribution in VR1</a> <li><a href=?table=Distribution2>Figure 3b: $E_{\mathrm{T}}^{\mathrm{miss}}$ Distribution in VR1</a> <li><a href=?table=Distribution3>Figure 3c: $m_{\gamma\gamma}$ Distribution in VR2</a> <li><a href=?table=Distribution4>Figure 3d: $E_{\mathrm{T}}^{\mathrm{miss}}$ Distribution in VR2</a> <li><a href=?table=Distribution5>Figure 4a: N-1 $m_{\gamma\gamma}$ Distribution for SR1h</a> <li><a href=?table=Distribution6>Figure 4b: N-1 $m_{\gamma\gamma}$ Distribution for SR1Z</a> <li><a href=?table=Distribution7>Figure 4c: N-1 $m_{\gamma\gamma}$ Distribution for SR2</a> <li><a href=?table=Distribution8>Auxiliary Figure 1: Signal and Validation Region Yields</a> </ul> <b>Tables:</b><ul> <li><a href=?table=YieldsTable1>Table 3: Signal Region Yields & Model-independent Limits</a> <li><a href=?table=Cutflow1>Auxiliary Table 1: Benchmark Signal Cutflows</a> </ul> <b>Cross section limits:</b><ul> <li><a href=?table=X-sectionU.L.1>Figure 5: 1D Cross-section Limits</a> <li><a href=?table=X-sectionU.L.2>Auxiliary Figure 3: 2D Cross-section Limits</a> </ul> <b>2D CL limits:</b><ul> <li><a href=?table=Exclusioncontour1>Figure 6: Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour2>Figure 6: $+1\sigma$ Variation for Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour3>Figure 6: $-1\sigma$ Variation for Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour4>Figure 6: Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour5>Figure 6: $+1\sigma$ Variation for Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour6>Figure 6: $-1\sigma$ Variation for Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> </ul> <b>2D Acceptance and Efficiency maps:</b><ul> <li><a href=?table=Acceptance1>Auxiliary Figure 4a: Acceptances SR1h</a> <li><a href=?table=Acceptance2>Auxiliary Figure 4b: Acceptances SR1Z</a> <li><a href=?table=Acceptance3>Auxiliary Figure 4c: Acceptances SR2</a> <li><a href=?table=Efficiency1>Auxiliary Figure 5a: Efficiencies SR1h</a> <li><a href=?table=Efficiency2>Auxiliary Figure 5b: Efficiencies SR1Z</a> <li><a href=?table=Efficiency3>Auxiliary Figure 5c: Efficiencies SR2</a> </ul>

Distribution of the diphoton invariant mass in validation region VR1. The solid histograms are stacked to show the SM expectations after the 2&times;2D background estimation technique is applied. Background and signal predictions are normalised to the luminosity. The background category "h (other)" includes events originating from VBF, Vh, ggF, thq, thW and bb&#772;h, all subdominant in this signature. Statistical and systematic uncertainties are indicated by the shaded area. The lower panel of each plot shows the ratio of the data to the SM prediction for the respective bin. The first and last bins include the underflows and overflows respectively.

Distribution of the missing transverse momentum in validation region VR1. The solid histograms are stacked to show the SM expectations after the 2&times;2D background estimation technique is applied. Background and signal predictions are normalised to the luminosity. The background category "h (other)" includes events originating from VBF, Vh, ggF, thq, thW and bb&#772;h, all subdominant in this signature. Statistical and systematic uncertainties are indicated by the shaded area. The lower panel of each plot shows the ratio of the data to the SM prediction for the respective bin. The first and last bins include the underflows and overflows respectively.

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Search for leptoquark pair production decaying into $te^- \bar{t}e^+$ or $t\mu^- \bar{t}\mu^+$ in multi-lepton final states in $pp$ collisions at 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
Eur.Phys.J.C 84 (2024) 818, 2024.
Inspire Record 2673386 DOI 10.17182/hepdata.150507

A search for leptoquark pair production decaying into $te^- \bar{t}e^+$ or $t\mu^- \bar{t}\mu^+$ in final states with multiple leptons is presented. The search is based on a dataset of $pp$ collisions at $\sqrt{s}$=13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139~fb$^{-1}$. Events are selected with two or more light leptons (electron or muon) and at least two jets out of which at least one jet is identified as coming from a $b$-hadron. Four signal regions, with the requirement of at least three light leptons, are considered based on the number of leptons of a given flavour. The main background processes are estimated using dedicated control regions in a simultaneous fit with the signal regions to data. No excess above the Standard Model background prediction is observed and 95% confidence level limits on the production cross section times branching ratio are derived as a function of the leptoquark mass. Under the assumption of exclusive decays into $te^{-}$ ($t\mu^{-}$), the corresponding lower limit on the scalar mixed-generation leptoquark mass $m_{\mathrm{LQ}_{\mathrm{mix}}^{\mathrm{d}}}$ is at 1.58 (1.59) TeV and on the vector leptoquark mass $m_{\tilde{U}_1}$ at 1.67 (1.67) TeV in the minimal coupling scenario and at 1.95 (1.95) TeV in the Yang-Mills scenario.

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Selection efficiency times acceptance summed over two signal regions for the scalar leptoquark signals as a function of $m_{\mathrm{LQ}_{mix}^{\mathrm{d}}}$, assuming B = 1.

Selection efficiency times acceptance summed over two signal regions for the vector leptoquark signals as a function of $m_{\tilde{U}_{1}}$, assuming B = 1 and Yang-Mills coupling scenario.

Summary of the observed and expected 95% CL upper limits on the cross section for $\mathrm{LQ}_{\mathrm{mix}}^{\mathrm{d}}$ pair production as a function of $m_{\mathrm{LQ}_{\mathrm{mix}}^{\mathrm{d}}}$ under the assumptions of B(LQ$\rightarrow te$)=1.

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Differential cross-section measurements of the production of four charged leptons in association with two jets using the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
JHEP 01 (2024) 004, 2024.
Inspire Record 2690799 DOI 10.17182/hepdata.144086

Differential cross-sections are measured for the production of four charged leptons in association with two jets. These measurements are sensitive to final states in which the jets are produced via the strong interaction as well as to the purely-electroweak vector boson scattering process. The analysis is performed using proton-proton collision data collected by ATLAS at $\sqrt{s}=13$ TeV and with an integrated luminosity of 140 fb$^{-1}$. The data are corrected for the effects of detector inefficiency and resolution and are compared to state-of-the-art Monte Carlo event generator predictions. The differential cross-sections are used to search for anomalous weak-boson self-interactions that are induced by dimension-six and dimension-eight operators in Standard Model effective field theory.

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Predicted and observed yields as a function of $m_{jj}$ in the VBS-Enhanced region. Overflow events are included in the last bin of the distribution.

Predicted and observed yields as a function of $m_{jj}$ in the VBS-Suppressed region. Overflow events are included in the last bin of the distribution.

Predicted and observed yields as a function of $m_{4\ell}$ in the VBS-Enhanced region. Overflow events are included in the last bin of the distribution.

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Measurement of $ZZ$ production cross-sections in the four-lepton final state in $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Lett.B 855 (2024) 138764, 2024.
Inspire Record 2723369 DOI 10.17182/hepdata.144768

This paper reports cross-section measurements of $ZZ$ production in $pp$ collisions at $\sqrt{s}=13.6$ TeV at the Large Hadron Collider. The data were collected by the ATLAS detector in 2022, and correspond to an integrated luminosity of 29 fb$^-1$. Events in the $ZZ\rightarrow4\ell$ ($\ell = e$, $\mu$) final states are selected and used to measure the inclusive and differential cross-sections in a fiducial region defined close to the analysis selections. The inclusive cross-section is further extrapolated to the total phase space with a requirement of 66 $< m_Z <$ 116 GeV for both $Z$ bosons, yielding $16.8 \pm 1.1$ pb. The results are well described by the Standard Model predictions.

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The measured differential cross-sections compared to the predictions in the $m_{4\ell}$ bins

The measured differential cross-sections compared to the predictions in the $p_T^{4\ell}$ bins


Observation of $W\gamma\gamma$ triboson production in proton-proton collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Lett.B 848 (2024) 138400, 2024.
Inspire Record 2686237 DOI 10.17182/hepdata.144508

This letter reports the observation of $W(\ell\nu)\gamma\gamma$ production in proton-proton collisions. This measurement uses the full Run 2 sample of events recorded at a center-of-mass energy of $\sqrt{s} = 13$ TeV by the ATLAS detector at the LHC, corresponding to an integrated luminosity of 140 fb$^{-1}$. Events with a leptonically-decaying $W$ boson and at least two photons are considered. The background-only hypothesis is rejected with an observed and expected significance of $5.6$ standard deviations. The inclusive fiducial production cross section of $W(e\nu)\gamma\gamma$ and $W(\mu\nu)\gamma\gamma$ events is measured to be $\sigma_{\mathrm{fid}} = 13.8 \pm 1.1 (\mathrm{stat}) \substack{+2.1 \\ -2.0} (\mathrm{syst}) \pm 0.1 (\mathrm{lumi})$ fb, in agreement with the Standard Model prediction.

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The measured fiducial $W(\rightarrow e\nu / \mu\nu)\gamma\gamma$ integrated cross section compared with both the signal event generator predictions.


Combination of searches for singly and doubly charged Higgs bosons produced via vector-boson fusion in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2024-189, 2024.
Inspire Record 2807795 DOI 10.17182/hepdata.153847

A combination of searches for singly and doubly charged Higgs bosons, $H^{\pm}$ and $H^{\pm\pm}$, produced via vector-boson fusion is performed using 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV, collected with the ATLAS detector during Run 2 of the Large Hadron Collider. Searches targeting decays to massive vector bosons in leptonic final states (electrons or muons) are considered. New constraints are reported on the production cross-section times branching fraction for charged Higgs boson masses between 200 GeV and 3000 GeV. The results are interpreted in the context of the Georgi-Machacek model for which the most stringent constraints to date are set for the masses considered in the combination.

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Post-fit $m_{\mathrm{WZ}}$ distribution in the signal region for the SM background-only hypothesis. Data are shown as black markers with vertical error bars representing the statistical uncertainty. Filled histograms show contributions of various SM processes, with the hatched band representing the total uncertainty. The line shows the prediction of the GM model for $\sin \theta_{\mathrm{H}} = 0.17$ and $m_{\mathrm{H_5}} = 375$ GeV, where the $\sin \theta_{\mathrm{H}}$ value corresponds to the expected $95\%$ CL limit for that $H_5$ mass.

Post-fit $m_{\mathrm{T}}$ distribution in the signal region for the SM background-only hypothesis. Data are shown as black markers with vertical error bars representing the statistical uncertainty. Filled histograms show contributions of various SM processes, with the hatched band representing the total uncertainty. The line shows the prediction of the GM model for $\sin \theta_{\mathrm{H}} = 0.17$ and $m_{\mathrm{H_5}} = 375$ GeV, where the $\sin \theta_{\mathrm{H}}$ value corresponds to the expected $95\%$ CL limit for that $H_5$ mass.

Expected and observed exclusion limits at 95% CL for $\sigma_{\mathrm{VBF}}(H_{5}^{\pm}) \times \mathcal{B}(H_{5}^{\pm} \to W^{\pm}Z)$ as a function of $m_{\mathrm{H_5}}$. The inner (outer) band represents the $68\%$ ($95\%$) confidence interval around the median expected limit.

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Studies of the energy dependence of diboson polarization fractions and the Radiation Amplitude Zero effect in WZ production with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
Phys.Rev.Lett. 133 (2024) 101802, 2024.
Inspire Record 2762099 DOI 10.17182/hepdata.149992

This Letter presents the first study of the energy-dependence of diboson polarization fractions in $WZ \rightarrow \ell\nu \ell'\ell'~(\ell, \ell'=e, \mu)$ production. The data set used corresponds to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally-polarized bosons are defined. A non-zero fraction of events with two longitudinally-polarized bosons is measured with an observed significance of 5.3 standard deviations in the region with $100<p_T^Z\leq200$ GeV and 1.6 standard deviations in the region with $p_T^Z>200$ GeV, where $p_T^Z$ is the transverse momentum of the $Z$ boson. This Letter also reports the first study of the Radiation Amplitude Zero effect. Events with two transversely-polarized bosons are analyzed for the $\Delta Y(\ell_W Z)$ and $\Delta Y(WZ)$ distributions defined respectively as the rapidity difference between the lepton from the $W$ boson decay and the $Z$ boson and the rapidity difference between the $W$ boson and the $Z$ boson. Significant suppression of events near zero is observed in both distributions. Unfolded $\Delta Y(\ell_W Z)$ and $\Delta Y(WZ)$ distributions are also measured and compared to theoretical predictions.

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Polarization fractions in the region with $100<p_T^Z\leq200$ GeV using three unconstrained parameters.

Polarization fractions in the region with $p_T^Z>200$ GeV using three unconstrained parameters.

Fraction of events where both bosons are longitudinally polarized in the region with $100<p_T^Z\leq200$ GeV using two unconstrained parameters.

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Search for neutral long-lived particles that decay into displaced jets in the ATLAS calorimeter in association with leptons or jets using $pp$ collisions at $\sqrt{s}=13$ TeV

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2024-181, 2024.
Inspire Record 2807458 DOI 10.17182/hepdata.153520

A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV delivered by the LHC is presented. The analysis is composed of three channels. The first targets pair-produced LLPs, where at least one LLP is produced with sufficiently low boost that its decay products can be resolved as separate jets. The second and third channels target LLPs respectively produced in association with a $W$ or $Z$ boson that decays leptonically. In each channel, different search regions target different kinematic regimes, to cover a broad range of LLP mass hypotheses and models. No excesses of events relative to the background predictions are observed. Higgs boson branching fractions to pairs of hadronically decaying neutral LLPs larger than 1% are excluded at 95% confidence level for proper decay lengths in the range of 30 cm to 4.5 m depending on the LLP mass, a factor of three improvement on previous searches in the hadronic calorimeter. The production of long-lived dark photons in association with a $Z$ boson with cross-sections above 0.1 pb is excluded for dark photon mean proper decay lengths in the range of 20 cm to 50 m, improving previous ATLAS results by an order of magnitude. Finally, long-lived photo-phobic axion-like particle models are probed for the first time by ATLAS, with production cross-sections above 0.1 pb excluded in the 0.1 mm to 10 m range.

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Observed (solid line) and expected (dashed line) upper limits at the 95&percnt; CL on the cross-section times branching fraction as a function of c&tau; for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.

Observed (solid line) and expected (dashed line) upper limits at the 95&percnt; CL on the cross-section times branching fraction as a function of c&tau; for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.

Observed (solid line) and expected (dashed line) upper limits at the 95&percnt; CL on the cross-section times branching fraction as a function of c&tau; for a selection of HS signal models in the CalR+2J channel for HS models with mediator masses of (a) 125 GeV, (b) 600 GeV and (c) 1000 GeV.

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Differential cross-sections for events with missing transverse momentum and jets measured with the ATLAS detector in 13 TeV proton-proton collisions

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
JHEP 08 (2024) 223, 2024.
Inspire Record 2765017 DOI 10.17182/hepdata.149990

Measurements of inclusive, differential cross-sections for the production of events with missing transverse momentum in association with jets in proton-proton collisions at $\sqrt{s}=13~$TeV are presented. The measurements are made with the ATLAS detector using an integrated luminosity of $140~$fb$^{-1}$ and include measurements of dijet distributions in a region in which vector-boson fusion processes are enhanced. They are unfolded to correct for detector resolution and efficiency within the fiducial acceptance, and are designed to allow robust comparisons with a wide range of theoretical predictions. A measurement of differential cross sections for the $Z~\to \nu\nu$ process is made. The measurements are generally well-described by Standard Model predictions except for the dijet invariant mass distribution. Auxiliary measurements of the hadronic system recoiling against isolated leptons, and photons, are also made in the same phase space. Ratios between the measured distributions are then derived, to take advantage of cancellations in modelling effects and some of the major systematic uncertainties. These measurements are sensitive to new phenomena, and provide a mechanism to easily set constraints on phenomenological models. To illustrate the robustness of the approach, these ratios are compared with two common Dark Matter models, where the constraints derived from the measurement are comparable to those set by dedicated detector-level searches.

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The measured $p_\text{T}^\text{miss}$ differential cross-sections in the $p_\text{T}^\text{miss}+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.

The measured $p_\text{T}^\text{recoil}$ differential cross-sections in the $1\mu+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.

The measured $p_\text{T}^\text{recoil}$ differential cross-sections in the $1e+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.

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