A search for dark matter (DM) particles produced in association with a hadronically decaying vector boson is performed using $pp$ collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$, recorded by the ATLAS detector at the Large Hadron Collider. This analysis improves on previous searches for processes with hadronic decays of $W$ and $Z$ bosons in association with large missing transverse momentum (mono-$W/Z$ searches) due to the larger dataset and further optimization of the event selection and signal region definitions. In addition to the mono-$W/Z$ search, the as yet unexplored hypothesis of a new vector boson $Z^\prime$ produced in association with dark matter is considered (mono-$Z^\prime$ search). No significant excess over the Standard Model prediction is observed. The results of the mono-$W/Z$ search are interpreted in terms of limits on invisible Higgs boson decays into dark matter particles, constraints on the parameter space of the simplified vector-mediator model and generic upper limits on the visible cross sections for $W/Z$+DM production. The results of the mono-$Z^\prime$ search are shown in the framework of several simplified-model scenarios involving DM production in association with the $Z^\prime$ boson.
The product of the acceptance and effifiency. Defined as the number of signal events satisfying the full set of selection criteria, divided by the total number of generated signal events, after the full event selection for the combined mono-W and mono-Z signal of the simplified vector-mediator model, shown in dependence on mass of the Z' mediator (mZp). For a given model, the signal contributions from each category are summed together.
The product of the acceptance and effifiency. Defined as the number of signal events satisfying the full set of selection criteria, divided by the total number of generated signal events, after the full event selection for the mono-Z' dark fermion and dark-Higgs signal models, shown in dependence on the mass of the Z' mediator (mZp). For a given model, the signal contributions from each category are summed together.
The observed and expected MET distributions with 36.1fb-1 of data with sqrt(s) = 13 TeV in the mono-W/Z signal region with the merged event topology after the profile-likelihood fit. This is shown for the 0b-tagged jet, high purity, event category.
Several extensions of the Standard Model predict the production of dark matter particles at the LHC. An uncharted signature of dark matter particles produced in association with $VV=W^\pm W^\mp$ or $ZZ$ pairs from a decay of a dark Higgs boson $s$ is searched for using 139 fb$^{-1}$ of $pp$ collisions recorded by the ATLAS detector at a center-of-mass energy of 13 TeV. The $s\to V(q\bar q)V(q\bar q)$ decays are reconstructed with a novel technique aimed at resolving the dense topology from boosted $VV$ pairs using jets in the calorimeter and tracking information. Dark Higgs scenarios with $m_s > 160$ GeV are excluded.
Data overlaid on SM background post-fit yields stacked in each SR and CR category and E<sub>T</sub><sup>miss</sup> bin with the maximum-likelihood estimators set to the conditional values of the CR-only fit, and propagated to SR and CRs. Pre-fit uncertainties cover differences between the data and pre-fit background prediction.
Dominant sources of uncertainty for three dark Higgs scenarios after the fit to Asimov data generated from the expected values of the maximum-likelihood estimators including predicted signals with m<sub>Z'</sub> = 1 TeV and m<sub>s</sub> of (a) 160 GeV, (b) 235 GeV, and (c) 310 GeV. The uncertainty in the fitted signal yield relative to the theory prediction is presented. Total is the quadrature sum of statistical and total systematic uncertainties, which consider correlations.
The ratios (μ) of the 95% C.L. upper limits on the combined s→ W<sup>±</sup>W<sup>∓</sup> and s→ ZZ cross section to simplified model expectations for the m<sub>Z'</sub>=0.5 TeV scenario, for various m<sub>s</sub> hypotheses. The observed limits (solid line) are consistent with the expectation under the SM-only hypothesis (dashed line) within uncertainties (filled band), except for a small excess for m<sub>s</sub>=160 GeV, discussed in the text.
This paper presents a search for dark matter, $\chi$, using events with a single top quark and an energetic $W$ boson. The analysis is based on proton-proton collision data collected with the ATLAS experiment at $\sqrt{s}=$ 13 TeV during LHC Run 2 (2015-2018), corresponding to an integrated luminosity of 139 fb$^{-1}$. The search considers final states with zero or one charged lepton (electron or muon), at least one $b$-jet and large missing transverse momentum. In addition, a result from a previous search considering two-charged-lepton final states is included in the interpretation of the results. The data are found to be in good agreement with the Standard Model predictions and the results are interpreted in terms of 95% confidence-level exclusion limits in the context of a class of dark matter models involving an extended two-Higgs-doublet sector together with a pseudoscalar mediator particle. The search is particularly sensitive to on-shell production of the charged Higgs boson state, $H^{\pm}$, arising from the two-Higgs-doublet mixing, and its semi-invisible decays via the mediator particle, $a$: $H^{\pm} \rightarrow W^\pm a (\rightarrow \chi\chi)$. Signal models with $H^{\pm}$ masses up to 1.5 TeV and $a$ masses up to 350 GeV are excluded assuming a tan$\beta$ value of 1. For masses of $a$ of 150 (250) GeV, tan$\beta$ values up to 2 are excluded for $H^{\pm}$ masses between 200 (400) GeV and 1.5 TeV. Signals with tan$\beta$ values between 20 and 30 are excluded for $H^{\pm}$ masses between 500 and 800 GeV.
<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>Exclusion contours:</b> <ul> <li><a href="?table=highst_mamh_obs">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mamh_exp">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_mhtb_lowma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mhtb_lowma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_mhtb_highma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mhtb_highma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mamh_obs">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mamh_exp">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mhtb_lowma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mhtb_lowma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mhtb_highma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mhtb_highma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mamh_obs">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mamh_exp">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mhtb_lowma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mhtb_lowma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mhtb_highma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mhtb_highma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mamh_obs">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mamh_exp">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_lowma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_lowma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_highma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_highma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mamh_obs">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mamh_exp">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mhtb_lowma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mhtb_lowma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mhtb_highma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mhtb_highma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mamh_obs">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_mamh_exp">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_lowma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_lowma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_highma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mamh_obs">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mamh_exp">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mhtb_lowma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mhtb_lowma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mhtb_highma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mhtb_highma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mamh_exp">2L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mhtb_lowma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mhtb_highma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_dmtt_mamh_obs">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mamh_exp">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=highst_dmtt_mhtb_lowma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mhtb_lowma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=highst_dmtt_mhtb_highma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mhtb_highma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mamh_obs">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mamh_exp">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mhtb_lowma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mhtb_lowma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mhtb_highma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mhtb_highma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mamh_obs">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mamh_exp">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_lowma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_lowma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_highma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_highma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mamh_obs">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mamh_exp">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_lowma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_lowma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_highma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_highma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mamh_obs">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mamh_exp">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_lowma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_lowma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_highma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_highma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mamh_obs">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mamh_exp">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_lowma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_lowma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_highma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_highma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mamh_obs">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mamh_exp">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_lowma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_lowma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_highma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_highma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mamh_exp">2L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_lowma_obs">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_lowma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_highma_obs">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_highma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> </ul> <b>Upper limits:</b> <ul> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=SR0L_mwtagged">0L region m(b1,W-tagged)</a> <li><a href="?table=SR0L_mtbmet">0L region m_{\mathrm{T}}^{\mathrm{b,E_{\mathrm{T}^{\mathrm{miss}}}}}</a> <li><a href="?table=SR0L_nwtagged">0L region N_{\mathrm{W-tagged}}</a> <li><a href="?table=SR1L_Had_mbj">1L hadronic top $m_{\mathrm{b1},\mathrm{\cancel{b1}}}$</a> <li><a href="?table=SR1L_Lep_mbj">1L leptonic top $m_{\mathrm{b1},\mathrm{\cancel{b1}}}$</a> <li><a href="?table=SR1L_Lep_nwtaggged">1L leptonic top region N_{\mathrm{W-tagged}}</a> </ul> <b>Cut flows:</b> <ul> <li><a href="?table=cutflow_SR0L">Cutflow of 4 signal points in the 0L regions.</a> <li><a href="?table=cutflow_SR1L_Had">Cutflow of 4 signal points in the 1L hadronic top regions.</a> <li><a href="?table=cutflow_SR1L_Lep">Cutflow of 4 signal points in the 1L leptonic top region.</a> </ul> <b>Acceptance and efficiencies:</b> <ul> <li> <b>highst_grid1_0L:</b> <a href="?table=highst_grid1_Acc_0L">Acceptance table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=highst_grid1_Eff_0L">Efficiency table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>highst_grid2_0L:</b> <a href="?table=highst_grid2_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=highst_grid2_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>highst_grid3_0L:</b> <a href="?table=highst_grid3_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=highst_grid3_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>highst_grid1_1L:</b> <a href="?table=highst_grid1_Acc_1L">Acceptance table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=highst_grid1_Eff_1L">Efficiency table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>highst_grid2_1L:</b> <a href="?table=highst_grid2_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=highst_grid2_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>highst_grid3_1L:</b> <a href="?table=highst_grid3_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=highst_grid3_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>lowst_grid1_0L:</b> <a href="?table=lowst_grid1_Acc_0L">Acceptance table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=lowst_grid1_Eff_0L">Efficiency table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>lowst_grid2_0L:</b> <a href="?table=lowst_grid2_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=lowst_grid2_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>lowst_grid3_0L:</b> <a href="?table=lowst_grid3_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=lowst_grid3_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>lowst_grid1_1L:</b> <a href="?table=lowst_grid1_Acc_1L">Acceptance table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=lowst_grid1_Eff_1L">Efficiency table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>lowst_grid2_1L:</b> <a href="?table=lowst_grid2_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=lowst_grid2_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>lowst_grid3_1L:</b> <a href="?table=lowst_grid3_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=lowst_grid3_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> </ul> <b>Truth Code snippets</b> are available under "Resources" (purple button on the left)
The observed exclusion contour at 95% CL as a function of the $m_a$ vs. $m_{H^{\pm}}$ and assuming tan$\beta$ = 1, $m_{\mathrm{DM}} = 10 \mathrm{GeV}$, $g_{\chi} = 1$ and sin$\theta = 0.7$. Masses that are within the contours are excluded. Only signals simulating the tW+DM final states are considered in this contour.
The expected exclusion contour at 95% CL as a function of the $m_a$ vs. $m_{H^{\pm}}$ and assuming tan$\beta$ = 1, $m_{\mathrm{DM}} = 10 \mathrm{GeV}$, $g_{\chi} = 1$ and sin$\theta = 0.7$. Masses that are within the contours are excluded. Only signals simulating the tW+DM final states are considered in this contour.
Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140 fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or $b$-jet and either one lepton ($e$, $\mu$), photon, or second light jet or $b$-jet in the anomalous regions. No significant deviations from the background hypotheses are observed.
Distributions of the anomaly score from the AE for data and five benchmark BSM models. Their legends, from top to bottom, are; (1) charged Higgs boson production in association with a top quark, $tbH^{+}$ with $H^{+} \rightarrow t\bar{b}$; (2) a Kaluza-Klein gauge boson, $W_{KK}$, with the SM $W$ boson and a radion $\phi$; (3) a $Z'$ boson decaying to a composite lepton $E$ and $\ell$, with $E \rightarrow Z\ell$ with a mass of 0.5 TeV; (4) the SSM $W$'$\rightarrow W Z' \rightarrow \ell\nu q\bar{q}$; (5) a simplified dark-matter model with an $Z$ axial-vector mediator $Z' \rightarrow q\bar{q}$, where one of the quarks radiates a $W$ boson decaying to $\ell\nu$. The BSM predictions represent the expected number of events from 140 $fb^{-1}$ of data for heavy particle ($H^{+}$ ,$W_{KK}$ , $Z'$ , $W'$ and $Z'$, respectively) masses around 2 TeV. The distributions for the BSM models are smoothed to remove fluctuations due to low MC event counts. The vertical lines indicate the start of the three anomaly regions (ARs). The labels of the three ARs indicate the visible cross section for hypothetical processes yielding the same number of events as observed in the 140 $fb^{-1}$ dataset. The AE is applied to preselected events without any requirements on invariant mass distributions.
Invariant mass distributions of jet+Y for $M_{jY}$ > 0.3 TeV in the 10 pb AR along with the fit of Eq. (1). The fits are represented by the lines, while the associated statistical uncertainties are indicated by the shaded bands. The lower panels show the bin-by-bin significances of deviations from the fit, calculated as $(d_{\textit{i}} - f_{i})/\delta_{\textit{i}}$, where $d_{i}$ is the data yield, $f_{\textit{i}}$ is the fit value, and $\delta_{i}$ is the data uncertainty in the $\textit{i}$-th bin.
Values of $\Delta Z$ for the discovery sensitivity, as defined in the text, as a function of the invariant mass $\textit{m}$. The j+j invariant mass distribution is calculated in the 10 pb AR. Positive percentages indicate improvements in sensitivity. Horizontal dashed lines are drawn at 100% and 200% to guide the eye. The five benchmark BSM models are (1) charged Higgs boson production in association with a top quark, $tbH^{+}$ with $H^{+} \rightarrow t\bar{b}$; (2) a Kaluza-Klein gauge boson, $W_{KK}$, with the SM $W$ boson and a radion $\phi$; (3) a $Z'$ boson decaying to a composite lepton $E$ and $\ell$, with $E \rightarrow Z\ell$; (4) the sequential standard model $W' \rightarrow W Z' \rightarrow \ell\nu q\bar{q}$; (5) a simplified dark-matter model with an axial-vector mediator $Z' \rightarrow q\bar{q}$, where one of the quarks radiates a $W$ boson decaying to $\ell\nu$. The multiple markers shown for the composite-lepton model at the same invariant mass values correspond to different composite lepton ($E$) masses between 0.25 and 3.5 TeV. The center positions of the markers are set to the masses of the corresponding heavy particles.
Several extensions of the Standard Model predict the production of dark matter particles at the LHC. A search for dark matter particles produced in association with a dark Higgs boson decaying into $W^{+}W^{-}$ in the $\ell^\pm\nu q \bar q'$ final states with $\ell=e,\mu$ is presented. This analysis uses 139 fb$^{-1}$ of $pp$ collisions recorded by the ATLAS detector at a centre-of-mass energy of 13 TeV. The $W^\pm \to q\bar q'$ decays are reconstructed from pairs of calorimeter-measured jets or from track-assisted reclustered jets, a technique aimed at resolving the dense topology from a pair of boosted quarks using jets in the calorimeter and tracking information. The observed data are found to agree with Standard Model predictions. Scenarios with dark Higgs boson masses ranging between 140 and 390 GeV are excluded.
Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>β=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=500 GeV, with the preselections applied.
Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>β=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=1000 GeV, with the preselections applied.
Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>β=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=1700 GeV, with the preselections applied.
Forum