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 $\tilde{G}$ either via a Higgs $h$ or $Z$ 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.
<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 2×2D 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 bb̄h, 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 2×2D 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 bb̄h, 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.
Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using $139\,$fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13\,$TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or higgsino production decaying via Standard Model $W$, $Z$, or $h$ bosons are combined to extend the mass reach to the produced SUSY particles by 30-100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% CL cross-section upper limits by 15%-40%.
Expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.
$+1\sigma$ expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.
$-1\sigma$ expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.
This paper presents a search for pair production of higgsinos, the supersymmetric partners of the Higgs bosons, in scenarios with gauge-mediated supersymmetry breaking. Each higgsino is assumed to decay into a Higgs boson and a nearly massless gravitino. The search targets events where each Higgs boson decays into $b\bar{b}$, leading to a reconstructed final state with at least three energetic $b$-jets and missing transverse momentum. Two complementary analysis channels are used, with each channel specifically targeting either low or high values of the higgsino mass. The low-mass (high-mass) channel exploits 126 (139) fb$^{-1}$ of $\sqrt{s}=13$ TeV data collected by the ATLAS detector during Run 2 of the Large Hadron Collider. No significant excess above the Standard Model prediction is found. At 95% confidence level, masses between 130 GeV and 940 GeV are excluded for higgsinos decaying exclusively into Higgs bosons and gravitinos. Exclusion limits as a function of the higgsino decay branching ratio to a Higgs boson are also reported.
Post-fit SR yields of the high-mass channel. The upper panel shows the observed number of events, as well the post-fit background predictions in each region. The bottom panel shows the ratio of the observed data and the total background prediction. The shaded areas correspond to the total statistical and systematic uncertainties obtained after the fit and described in Section 6.
Post-fit SR yields of the high-mass channel. The upper panel shows the observed number of events, as well the post-fit background predictions in each region. The bottom panel shows the ratio of the observed data and the total background prediction. The shaded areas correspond to the total statistical and systematic uncertainties obtained after the fit and described in Section 6.
Post-fit SR yields of the high-mass channel. The upper panel shows the observed number of events, as well the post-fit background predictions in each region. The bottom panel shows the ratio of the observed data and the total background prediction. The shaded areas correspond to the total statistical and systematic uncertainties obtained after the fit and described in Section 6.
Higgsinos with masses near the electroweak scale can solve the hierarchy problem and provide a dark matter candidate, while detecting them at the LHC remains challenging if their mass-splitting is $\mathcal{O}$(1 GeV). This Letter presents a novel search for nearly mass-degenerate higgsinos in events with an energetic jet, missing transverse momentum, and a low-momentum track with a significant transverse impact parameter using 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV collected by the ATLAS experiment. For the first time since LEP, a range of mass-splittings between the lightest charged and neutral higgsinos from 0.3 GeV to 0.9 GeV is excluded at 95% confidence level, with a maximum reach of approximately 170 GeV in the higgsino mass.
Number of expected and observed data events in the SR (top), and the model-independent upper limits obtained from their consistency (bottom). The symbol $\tau_{\ell}$ ($\tau_{h}$) refers to fully-leptonic (hadron-involved) tau decays. The Others category includes contributions from minor background processes including $t\bar{t}$, single-top and diboson. The individual uncertainties can be correlated and do not necessarily sum up in quadrature to the total uncertainty. The bottom section shows the observed 95% CL upper limits on the visible cross-section ($\langle\epsilon\sigma\rangle_{\mathrm{obs}}^{95}$), on the number of generic signal events ($S_{\mathrm{obs}}^{95}$) as well as the expected limit ($S_{\mathrm{exp}}^{95}$) given the expected number (and $\pm 1\sigma$ deviations from the expectation) of background events.
Expected (dashed black line) and observed (solid red line) 95% CL exclusion limits on the higgsino simplified model being considered. These are shown with $\pm 1\sigma_{\mathrm{exp}}$ (yellow band) from experimental systematic and statistical uncertainties, and with $\pm 1\sigma_{\mathrm{theory}}^{\mathrm{SUSY}}$ (red dotted lines) from signal cross-section uncertainties, respectively. The limits set by the latest ATLAS searches using the soft lepton and disappearing track signatures are illustrated by the blue and green regions, respectively, while the limit imposed by the LEP experiments is shown in gray. The dot-dashed gray line indicates the predicted mass-splitting for the pure higgsino scenario.
Expected (dashed black line) and observed (solid red line) 95% CL exclusion limits on the higgsino simplified model being considered. These are shown with $\pm 1\sigma_{\mathrm{exp}}$ (yellow band) from experimental systematic and statistical uncertainties, and with $\pm 1\sigma_{\mathrm{theory}}^{\mathrm{SUSY}}$ (red dotted lines) from signal cross-section uncertainties, respectively. The limits set by the latest ATLAS searches using the soft lepton and disappearing track signatures are illustrated by the blue and green regions, respectively, while the limit imposed by the LEP experiments is shown in gray. The dot-dashed gray line indicates the predicted mass-splitting for the pure higgsino scenario.
A search for the decay of the Higgs boson to a $Z$ boson and a light, pseudoscalar particle, $a$, decaying respectively to two leptons and to two photons is reported. The search uses the full LHC Run 2 proton-proton collision data at $\sqrt{s}=13$ TeV, corresponding to 139 fb$^{-1}$ collected by the ATLAS detector. This is one of the first searches for this specific decay mode of the Higgs boson, and it probes unexplored parameter space in models with axion-like particles (ALPs) and extended scalar sectors. The mass of the $a$ particle is assumed to be in the range 0.1-33 GeV. The data are analysed in two categories: a merged category where the photons from the $a$ decay are reconstructed in the ATLAS calorimeter as a single cluster, and a resolved category in which two separate photons are detected. The main background processes are from Standard Model $Z$ boson production in association with photons or jets. The data are in agreement with the background predictions, and upper limits on the branching ratio of the Higgs boson decay to $Za$ times the branching ratio $a\to\gamma\gamma$ are derived at the 95% confidence level and they range from 0.08% to 2% depending on the mass of the $a$ particle. The results are also interpreted in the context of ALP models.
Post-fit distribution for $m_{\gamma\gamma}$ for the resolved category in number of events per 0.2 GeV for data. The figure uses $pp$ collision data at $\sqrt{s}=13$ TeV corresponding to 139 fb$^{-1}$.
Post-fit distribution for $m_{\gamma\gamma}$ for the resolved category in number of events per 0.2 GeV for a signal distribution for $m_a = 9$ GeV, and the signal plus background fit with its background component. The branching ratio of the Higgs boson decay to $Za$ times the branching ratio $a $->$ \gamma \gamma$ is assumed to be 50%. The figure uses $pp$ collision data at $\sqrt{s}=13$ TeV corresponding to 139 fb$^{-1}$.
Post-fit final discriminating variable $\Delta R_{Z\gamma}$ in the signal region of the merged category. Signal distributions for $m_a$ values used in this category are overlayed for comparison, assuming a branching ratio of the Higgs boson decay to $Za$ times the branching ratio $a $->$ \gamma \gamma$ of 100%. The signal yields have been multiplied by 10 for better visibility. The figure uses $pp$ collision data at $\sqrt{s}=13$ TeV corresponding to 139 fb$^{-1}$.
A search for a heavy CP-odd Higgs boson, $A$, decaying into a $Z$ boson and a heavy CP-even Higgs boson, $H$, is presented. It uses the full LHC Run 2 dataset of $pp$ collisions at $\sqrt{s}=13$ TeV collected with the ATLAS detector, corresponding to an integrated luminosity of $140$ fb$^{-1}$. The search for $A\to ZH$ is performed in the $\ell^+\ell^- t\bar{t}$ and $\nu\bar{\nu}b\bar{b}$ final states and surpasses the reach of previous searches in different final states in the region with $m_H>350$ GeV and $m_A>800$ GeV. No significant deviation from the Standard Model expectation is found. Upper limits are placed on the production cross-section times the decay branching ratios. Limits with less model dependence are also presented as functions of the reconstructed $m(t\bar{t})$ and $m(b\bar{b})$ distributions in the $\ell^+\ell^- t\bar{t}$ and $\nu\bar{\nu}b\bar{b}$ channels, respectively. In addition, the results are interpreted in the context of two-Higgs-doublet models.
<b><u>Overview of HEPData Record</u></b><br> <b>Upper limits on cross-sections:</b> <ul> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=0.5">95% CL upper limit on ggF A->ZH(tt) production for tanb=0.5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=1">95% CL upper limit on ggF A->ZH(tt) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=5">95% CL upper limit on ggF A->ZH(tt) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=1">95% CL upper limit on bbA A->ZH(tt) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=5">95% CL upper limit on bbA A->ZH(tt) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=10">95% CL upper limit on bbA A->ZH(tt) production for tanb=10</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=0.5">95% CL upper limit on ggF A->ZH(bb) production for tanb=0.5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=1">95% CL upper limit on ggF A->ZH(bb) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=5">95% CL upper limit on ggF A->ZH(bb) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=1">95% CL upper limit on bbA A->ZH(bb) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=5">95% CL upper limit on bbA A->ZH(bb) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=10">95% CL upper limit on bbA A->ZH(bb) production for tanb=10</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=20">95% CL upper limit on bbA A->ZH(bb) production for tanb=20</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=m(tt),L3hi_Zin,ggF-production">m(tt) distribution in the L3hi_Zin region of the lltt channel</a> <li><a href="?table=m(bb),2tag,0L,ggF-production">m(bb) distribution in the 2 b-tag 0L region of the vvbb channel</a> <li><a href="?table=m(bb),3ptag,0L,bbA-production">m(bb) distribution in the 3p b-tag 0L region of the vvbb channel</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin450,bbA-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis with the bbA signal shown</a> <li><a href="?table=m(tt),L3hi_Zin,bbA-production">m(tt) distribution in the L3hi_Zin region of the lltt channel with the bbA signal shown</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin350,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=350 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin400,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=400 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin450,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin500,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=500 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin550,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=550 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin600,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=600 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin700,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=700 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin800,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin130,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=130 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin150,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=150 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin200,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=200 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin250,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=250 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin300,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin350,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=350 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin400,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=400 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin450,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=450 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin500,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=500 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin600,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=600 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin700,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=700 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin800,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin130,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=130 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin150,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=150 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin200,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=200 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin250,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=250 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin300,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin350,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=350 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin400,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=400 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin450,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=450 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin500,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=500 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin600,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=600 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin700,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=700 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin800,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,2L">Fit discriminant mT(VH) in the 2L region of the vvbb channel</a> <li><a href="?table=mTVH,2tag,em">Fit discriminant mT(VH) in the em region of the vvbb channel</a> <li><a href="?table=mTVH,3ptag,2L">Fit discriminant mT(VH) in the 2L region of the vvbb channel</a> <li><a href="?table=mTVH,3ptag,em">Fit discriminant mT(VH) in the em region of the vvbb channel</a> <li><a href="?table=lep3pt,L3hi_Zin">pT(lepton,3) distribution in the L3hi_Zin region of the lltt channel</a> <li><a href="?table=etaHrestVH,L3hi_Zin">eta(H,VH rest frame) distribution in the signal region of the lltt channel</a> <li><a href="?table=ETmiss,2tag,0L">ETmiss distribution in the 2 b-tag signal region of the vvbb channel</a> <li><a href="?table=mtopnear,2tag,0L">m(top,near) distribution in the 2 b-tag signal region of the vvbb channel</a> <li><a href="?table=ETmiss,3ptag,0L">ETmiss distribution in the 3p b-tag signal region of the vvbb channel</a> <li><a href="?table=mtopnear,3ptag,0L">m(top,near) distribution in the 3p b-tag signal region of the vvbb channel</a> </ul> <b>Observed local significance:</b> <ul> <li><a href="?table=Local%20significance,%20lltt,%20ggF%20production">ggF A->ZH->lltt signals</a> <li><a href="?table=Local%20significance,%20lltt,%20bbA%20production">bbA A->ZH->lltt signals</a> <li><a href="?table=Local%20significance,%20vvbb,%20ggF%20production">ggF A->ZH->vvbb signals</a> <li><a href="?table=Local%20significance,%20vvbb,%20bbA%20production">bbA A->ZH->vvbb signals</a> </ul> <b>Acceptance and efficiency:</b> <ul> <li><a href="?table=Acceptance*efficiency,%20lltt,%20ggF%20production">ggF A->ZH->lltt signals</a> <li><a href="?table=Acceptance*efficiency,%20lltt,%20bbA%20production">bbA A->ZH->lltt signals</a> <li><a href="?table=Acceptance*efficiency,%20vvbb,%20ggF%20production">ggF A->ZH->vvbb signals</a> <li><a href="?table=Acceptance*efficiency,%20vvbb,%20bbA%20production">bbA A->ZH->vvbb signals</a> </ul>
The distribution of the fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis. <br><br><a href="?table=overview">return to overview</a>
The distribution of the fit discriminant mTVH in the 2 b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis. <br><br><a href="?table=overview">return to overview</a>
A search for W' bosons decaying to a top and a bottom quark in final states including an electron or a muon is performed with the CMS detector at the LHC. The analyzed data correspond to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 Tev. Good agreement with the standard model expectation is observed and no evidence for the existence of the W' boson is found over the mass range examined. The largest observed deviation from the standard model expectation is found for a W' boson mass ($m_\mathrm{W'}$) hypothesis of 3.8 TeV with a relative decay width of 1%, with a local (global) significance of 2.6 (2.0) standard deviations. Upper limits on the production cross sections of W' bosons decaying to a top and a bottom quark are set. Left- and right-handed W' bosons with $m_\mathrm{W'}$ below 3.9 and 4.3 TeV, respectively, are excluded at the 95% confidence level, under the assumption that the new particle has a narrow decay width. Limits are also set for relative decay widths up to 30%. These are the most stringent limits to date on this W' boson decay channel.
Post-fit distributions of $M_{\ell v jj}$ in the $R0_A$ control subregion for muons. The lower panel reports the data minus the expected number of events normalized to the statistical uncertainty of the data. The orange band represents the systematic uncertainties also normalized to the statistical uncertainty of the data.
Post-fit distributions of $M_{\ell v jj}$ in the $R0_A$ control subregion for electrons. The lower panel reports the data minus the expected number of events normalized to the statistical uncertainty of the data. The orange band represents the systematic uncertainties also normalized to the statistical uncertainty of the data.
Post-fit distributions of $M_{\ell v jj}$ in the $R2B_A$ subregion for muons. All process yields and nuisance parameters are set to the values obtained from the background plus signal fit. The signal considered for the fit corresponds to the purely right-handed production of a W' with $m_{W'}$ of 3.6 TeV and a relative width of 1$\%$ of the $m_{W'}$, and is represented by the solid red line. The lower panels show the data minus the expected number of events, normalized to the statistical uncertainty of the data. The orange band represents the systematic uncertainties, also normalized to the statistical uncertainty of the data.
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.
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.
A search for a new massive charged gauge boson, $W'$, is performed with the ATLAS detector at the LHC. The dataset used in this analysis was collected from proton-proton collisions at a centre-of-mass energy of $\sqrt{s} =13$ TeV, and corresponds to an integrated luminosity of 139 fb$^{-1}$. The reconstructed $tb$ invariant mass is used to search for a $W'$ boson decaying into a top quark and a bottom quark. The result is interpreted in terms of a $W'$ boson with purely right-handed or left-handed chirality in a mass range of 0.5-6 TeV. Different values for the coupling of the $W'$ boson to the top and bottom quarks are considered, taking into account interference with single-top-quark production in the $s$-channel. No significant deviation from the background prediction is observed. The results are expressed as upper limits on the $W' \rightarrow tb$ production cross-section times branching ratio as a function of the $W'$-boson mass and in the plane of the coupling vs the $W'$-boson mass.
<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>Exclusion contours:</b> <ul> <li><a href="?table=contour_lh">$W^{\prime}_L$ exclusion contour</a> <li><a href="?table=contour_rh">$W^{\prime}_R$ exclusion contour</a> </ul> <b>Upper limits:</b> <ul> <li><a href="?table=limit_lh_gf05">$W^{\prime}_L$ $g^{\prime}/g$ = 0.5 upper limit</a> <li><a href="?table=limit_lh_gf10">$W^{\prime}_L$ $g^{\prime}/g$ = 1.0 upper limit</a> <li><a href="?table=limit_lh_gf20">$W^{\prime}_L$ $g^{\prime}/g$ = 2.0 upper limit</a> <li><a href="?table=limit_rh_gf05">$W^{\prime}_R$ $g^{\prime}/g$ = 0.5 upper limit</a> <li><a href="?table=limit_rh_gf10">$W^{\prime}_R$ $g^{\prime}/g$ = 1.0 upper limit</a> <li><a href="?table=limit_rh_gf20">$W^{\prime}_R$ $g^{\prime}/g$ = 2.0 upper limit</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=0l_sr1">0L channel Signal Region 1</a> <li><a href="?table=0l_sr2">0L channel Signal Region 2</a> <li><a href="?table=0l_sr3">0L channel Signal Region 3</a> <li><a href="?table=0l_vr">0L channel Validation Region</a> <li><a href="?table=1l_sr_2j1b">1L channel 2j1b Signal Region</a> <li><a href="?table=1l_sr_3j1b">1L channel 3j1b Signal Region</a> <li><a href="?table=1l_sr_2j2b">1L channel 2j2b Signal Region</a> <li><a href="?table=1l_sr_3j2b">1L channel 3j2b Signal Region</a> <li><a href="?table=1l_cr_2j1b">1L channel 2j1b Control Region</a> <li><a href="?table=1l_cr_3j1b">1L channel 3j1b Control Region</a> <li><a href="?table=1l_vr_2j1b">1L channel 2j1b Validation Region</a> <li><a href="?table=1l_vr_3j1b">1L channel 3j1b Validation Region</a> </ul> <b>Acceptance and efficiencies:</b> <ul> <li><a href="?table=acc_0l_lh_gf10">0L channel $W^{\prime}_L$ $g^{\prime}/g$ = 1.0 Acc. X Eff.</a> <li><a href="?table=acc_0l_lh_gf05">0L channel $W^{\prime}_L$ $g^{\prime}/g$ = 0.5 Acc. X Eff.</a> <li><a href="?table=acc_0l_lh_gf20">0L channel $W^{\prime}_L$ $g^{\prime}/g$ = 2.0 Acc. X Eff.</a> <li><a href="?table=acc_1l_lh_gf10">1L channel $W^{\prime}_L$ $g^{\prime}/g$ = 1.0 Acc. X Eff.</a> <li><a href="?table=acc_1l_lh_gf05">1L channel $W^{\prime}_L$ $g^{\prime}/g$ = 0.5 Acc. X Eff.</a> <li><a href="?table=acc_1l_lh_gf20">1L channel $W^{\prime}_L$ $g^{\prime}/g$ = 2.0 Acc. X Eff.</a> <li><a href="?table=acc_0l_rh_gf10">0L channel $W^{\prime}_R$ $g^{\prime}/g$ = 1.0 Acc. X Eff.</a> <li><a href="?table=acc_0l_rh_gf05">0L channel $W^{\prime}_R$ $g^{\prime}/g$ = 0.5 Acc. X Eff.</a> <li><a href="?table=acc_0l_rh_gf20">0L channel $W^{\prime}_R$ $g^{\prime}/g$ = 2.0 Acc. X Eff.</a> <li><a href="?table=acc_1l_rh_gf10">1L channel $W^{\prime}_R$ $g^{\prime}/g$ = 1.0 Acc. X Eff.</a> <li><a href="?table=acc_1l_rh_gf05">1L channel $W^{\prime}_R$ $g^{\prime}/g$ = 0.5 Acc. X Eff.</a> <li><a href="?table=acc_1l_rh_gf20">1L channel $W^{\prime}_R$ $g^{\prime}/g$ = 2.0 Acc. X Eff.</a> </ul>
Distribution (events/100 GeV) of the reconstructed $m_{tb}$ for data and backgrounds in the 0-lepton channel's signal region 1 after the background-only fit to data. The systematics uncertainty is shown for the post-fit background sum, including the background statistical uncertainty. The individual background components are obtained after the fit, too. There are also the pre-fit background sum and the expected signal distribution. The distribution of the $W^{\prime}$ boson signal for a mass of 3 TeV is normalised to the predicted cross-section. The last bin in each distribution includes overflow.
Distribution (events/100 GeV) of the reconstructed $m_{tb}$ for data and backgrounds in the 0-lepton channel's signal region 2 after the background-only fit to data. The systematics uncertainty is shown for the post-fit background sum, including the background statistical uncertainty. The individual background components are obtained after the fit, too. There are also the pre-fit background sum and the expected signal distribution. The distribution of the $W^{\prime}$ boson signal for a mass of 3 TeV is normalised to the predicted cross-section. The last bin in each distribution includes overflow.
A search is presented for a third-generation leptoquark (LQ) coupled exclusively to a $\tau$ lepton and a b quark. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector, corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with $\tau$ leptons and a varying number of jets originating from b quarks are considered, targeting the single and pair production of LQs, as well as nonresonant $t$-channel LQ exchange. An excess is observed in the data with respect to the background expectation in the combined analysis of all search regions. For a benchmark LQ mass of 2 TeV and an LQ-b-$\tau$ coupling strength of 2.5, the excess reaches a local significance of up to 2.8 standard deviations. Upper limits at the 95% confidence level are placed on the LQ production cross section in the LQ mass range 0.5-2.3 TeV, and up to 3 TeV for $t$-channel LQ exchange. Leptoquarks are excluded below masses of 1.22-1.88 TeV for different LQ models and varying coupling strengths up to 2.5. The study of nonresonant $\tau\tau$ production through $t$-channel LQ exchange allows lower limits on the LQ mass of up to 2.3 TeV to be obtained.
Product of acceptance and efficiency of a vector LQ signal as a function of LQ mass under the assumption of exclusive LQ couplings to b quarks and $\tau$ leptons. The acceptances and efficiencies are restricted to the sensitive region of $S_\mathrm{T}^\mathrm{MET} > 800\,\mathrm{GeV}$ and are computed with respect to all possible decay modes of two $\tau$ leptons.
Product of acceptance and efficiency of a vector LQ signal as a function of LQ mass under the assumption of exclusive LQ couplings to b quarks and $\tau$ leptons. The acceptances and efficiencies are restricted to the sensitive region of $\chi < 4$ and are computed with respect to all possible decay modes of two $\tau$ leptons.
Postfit distributions of $S_\mathrm{T}^\mathrm{MET}$ in the $\mathrm{e}\mu$ channel of the 0b category for the combined 2016-2018 data set after a simultaneous fit of the background and vector LQ signal to the data. The number of events in each bin are divided by the respective bin width. The last bin includes the overflow.
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