Date

Search for long-lived particles produced in $pp$ collisions at $\sqrt{s}=13$ TeV that decay into displaced hadronic jets in the ATLAS muon spectrometer

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.D 99 (2019) 052005, 2019.
Inspire Record 1704138 DOI 10.17182/hepdata.85748

A search for the decay of neutral, weakly interacting, long-lived particles using data collected by the ATLAS detector at the LHC is presented. The analysis in this paper uses 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV recorded in 2015-2016. The search employs techniques for reconstructing vertices of long-lived particles decaying into jets in the muon spectrometer exploiting a two vertex strategy and a novel technique that requires only one vertex in association with additional activity in the detector that improves the sensitivity for longer lifetimes. The observed numbers of events are consistent with the expected background and limits for several benchmark signals are determined.

122 data tables

- - - - - - - - - - - - - - - - - - - - <br/><b>Muon RoI Cluster trigger efficiency:</b> <br/><i>mPhi=100:</i> <a href="85748?version=1&table=Table1">Barrel</a> <i>mPhi=125:</i> <a href="85748?version=1&table=Table2">Barrel</a> <br/><i>mPhi=200:</i> <a href="85748?version=1&table=Table3">Barrel</a> <i>mPhi=400:</i> <a href="85748?version=1&table=Table4">Barrel</a> <br/><i>mPhi=600:</i> <a href="85748?version=1&table=Table5">Barrel</a> <i>mPhi=1000:</i> <a href="85748?version=1&table=Table6">Barrel</a> <br/><i>Stealth SUSY:</i> <a href="85748?version=1&table=Table7">Barrel</a> <br/><i>Baryogenesis nubb:</i> <a href="85748?version=1&table=Table8">Barrel</a> <i>Baryogenesis cbs:</i> <a href="85748?version=1&table=Table9">Barrel</a> <br/><i>Baryogenesis lcb:</i> <a href="85748?version=1&table=Table10">Barrel</a> <i>Baryogenesis tautaunu:</i> <a href="85748?version=1&table=Table11">Barrel</a> <br/><i>mPhi=100:</i> <a href="85748?version=1&table=Table12">Endcaps</a> <i>mPhi=125:</i> <a href="85748?version=1&table=Table13">Endcaps </a> <br/><i>mPhi=200:</i> <a href="85748?version=1&table=Table14">Endcaps</a> <i>mPhi=400:</i> <a href="85748?version=1&table=Table15">Endcaps</a> <br/><i>mPhi=600:</i> <a href="85748?version=1&table=Table16">Endcaps</a> <i>mPhi=1000:</i> <a href="85748?version=1&table=Table17">Endcaps</a> <br/><i>Stealth SUSY:</i> <a href="85748?version=1&table=Table18">Endcaps</a> <br/><i>Baryogenesis nubb:</i> <a href="85748?version=1&table=Table19">Endcaps</a> <i>Baryogenesis cbs:</i> <a href="85748?version=1&table=Table20">Endcaps</a> <br/><i>Baryogenesis lcb:</i> <a href="85748?version=1&table=Table21">Endcaps</a> <i>Baryogenesis tautaunu:</i> <a href="85748?version=1&table=Table22">Endcaps</a> <br/><b>MS vertex efficiency:</b> <br/><i>mPhi=100:</i> <a href="85748?version=1&table=Table23">Barrel</a> <i>mPhi=125:</i> <a href="85748?version=1&table=Table24">Barrel</a> <br/><i>mPhi=200:</i> <a href="85748?version=1&table=Table25">Barrel</a> <i>mPhi=400:</i> <a href="85748?version=1&table=Table26">Barrel</a> <br/><i>mPhi=600:</i> <a href="85748?version=1&table=Table27">Barrel</a> <i>mPhi=1000:</i> <a href="85748?version=1&table=Table28">Barrel</a> <br/><i>Stealth SUSY:</i> <a href="85748?version=1&table=Table29">Barrel</a> <br/><i>Baryogenesis nubb:</i> <a href="85748?version=1&table=Table30">Barrel</a> <i>Baryogenesis cbs:</i> <a href="85748?version=1&table=Table31">Barrel</a> <br/><i>Baryogenesis lcb:</i> <a href="85748?version=1&table=Table32">Barrel</a> <i>Baryogenesis tautaunu:</i> <a href="85748?version=1&table=Table33">Barrel</a> <br/><i>mPhi=100:</i> <a href="85748?version=1&table=Table34">Endcaps</a> <i>mPhi=125:</i> <a href="85748?version=1&table=Table35">Endcaps</a> <br/><i>mPhi=200:</i> <a href="85748?version=1&table=Table36">Endcaps</a> <i>mPhi=400:</i> <a href="85748?version=1&table=Table37">Endcaps</a> <br/><i>mPhi=600:</i> <a href="85748?version=1&table=Table38">Endcaps</a> <i>mPhi=1000:</i> <a href="85748?version=1&table=Table39">Endcaps</a> <br/><i>Stealth SUSY:</i> <a href="85748?version=1&table=Table40">Endcaps</a> <br/><i>Baryogenesis nubb:</i> <a href="85748?version=1&table=Table41">Endcaps</a> <i>Baryogenesis cbs:</i> <a href="85748?version=1&table=Table42">Endcaps</a> <br/><i>Baryogenesis lcb:</i> <a href="85748?version=1&table=Table43">Endcaps</a> <i>Baryogenesis tautaunu:</i> <a href="85748?version=1&table=Table44">Endcaps</a> <br/><b>Exclusion limits:</b> <br/><i>mPhi=125, mS=5:</i> <a href="85748?version=1&table=Table45">2Vx</a> <a href="85748?version=1&table=Table46">1Vx</a> <a href="85748?version=1&table=Table47">Combined</a> <br/><i>mPhi=125, mS=8:</i> <a href="85748?version=1&table=Table48">2Vx</a> <a href="85748?version=1&table=Table49">1Vx</a> <a href="85748?version=1&table=Table50">Combined</a> <br/><i>mPhi=125, mS=15:</i> <a href="85748?version=1&table=Table51">2Vx</a> <a href="85748?version=1&table=Table52">1Vx</a> <a href="85748?version=1&table=Table53">Combined</a> <br/><i>mPhi=125, mS=25:</i> <a href="85748?version=1&table=Table54">2Vx</a> <a href="85748?version=1&table=Table55">1Vx</a> <a href="85748?version=1&table=Table56">Combined</a> <br/><i>mPhi=125, mS=40:</i> <a href="85748?version=1&table=Table57">2Vx</a> <a href="85748?version=1&table=Table58">1Vx</a> <a href="85748?version=1&table=Table59">Combined</a> <br/><i>Stealth SUSY mG=250:</i> <a href="85748?version=1&table=Table60">2Vx</a> <br/><i>Stealth SUSY mG=500:</i> <a href="85748?version=1&table=Table61">2Vx</a> <a href="85748?version=1&table=Table62">1Vx</a> <a href="85748?version=1&table=Table63">Combined</a> <br/><i>Stealth SUSY mG=800:</i> <a href="85748?version=1&table=Table64">2Vx</a> <a href="85748?version=1&table=Table65">1Vx</a> <a href="85748?version=1&table=Table66">Combined</a> <br/><i>Stealth SUSY mG=1200:</i> <a href="85748?version=1&table=Table67">2Vx</a> <a href="85748?version=1&table=Table68">1Vx</a> <a href="85748?version=1&table=Table69">Combined</a> <br/><i>Stealth SUSY mG=1500:</i> <a href="85748?version=1&table=Table70">2Vx</a> <a href="85748?version=1&table=Table71">1Vx</a> <a href="85748?version=1&table=Table72">Combined</a> <br/><i>Stealth SUSY mG=2000:</i> <a href="85748?version=1&table=Table73">2Vx</a> <a href="85748?version=1&table=Table74">1Vx</a> <a href="85748?version=1&table=Table75">Combined</a> <br/><i>mPhi=100, mS=8:</i> <a href="85748?version=1&table=Table76">2Vx</a> <br/><i>mPhi=100, mS=25:</i> <a href="85748?version=1&table=Table77">2Vx</a> <br/><i>mPhi=200, mS=8:</i> <a href="85748?version=1&table=Table78">2Vx</a> <br/><i>mPhi=200, mS=25:</i> <a href="85748?version=1&table=Table79">2Vx</a> <br/><i>mPhi=200, mS=50:</i> <a href="85748?version=1&table=Table80">2Vx</a> <br/><i>mPhi=400, mS=50:</i> <a href="85748?version=1&table=Table81">2Vx</a> <br/><i>mPhi=400, mS=100:</i> <a href="85748?version=1&table=Table82">2Vx</a> <br/><i>mPhi=600, mS=50:</i> <a href="85748?version=1&table=Table83">2Vx</a> <br/><i>mPhi=600, mS=150:</i> <a href="85748?version=1&table=Table84">2Vx</a> <br/><i>mPhi=1000, mS=50:</i> <a href="85748?version=1&table=Table85">2Vx</a> <br/><i>mPhi=1000, mS=150:</i> <a href="85748?version=1&table=Table86">2Vx</a> <br/><i>mPhi=1000, mS=400:</i> <a href="85748?version=1&table=Table87">2Vx</a> <br/><i>Baryogenesis nubb, mChi=10</i> <a href="85748?version=1&table=Table88">2Vx</a> <a href="85748?version=1&table=Table89">1Vx</a> <a href="85748?version=1&table=Table90">Combined</a> <br/><i>Baryogenesis nubb, mChi=30</i> <a href="85748?version=1&table=Table91">2Vx</a> <a href="85748?version=1&table=Table92">1Vx</a> <a href="85748?version=1&table=Table93">Combined</a> <br/><i>Baryogenesis nubb, mChi=50</i> <a href="85748?version=1&table=Table94">2Vx</a> <a href="85748?version=1&table=Table95">1Vx</a> <a href="85748?version=1&table=Table96">Combined</a> <br/><i>Baryogenesis nubb, mChi=100</i> <a href="85748?version=1&table=Table97">2Vx</a> <br/><i>Baryogenesis cbs, mChi=10</i> <a href="85748?version=1&table=Table98">2Vx</a> <a href="85748?version=1&table=Table99">1Vx</a> <a href="85748?version=1&table=Table100">Combined</a> <br/><i>Baryogenesis cbs, mChi=30</i> <a href="85748?version=1&table=Table101">2Vx</a> <a href="85748?version=1&table=Table102">1Vx</a> <a href="85748?version=1&table=Table103">Combined</a> <br/><i>Baryogenesis cbs, mChi=50</i> <a href="85748?version=1&table=Table104">2Vx</a> <a href="85748?version=1&table=Table105">1Vx</a> <a href="85748?version=1&table=Table106">Combined</a> <br/><i>Baryogenesis cbs, mChi=100</i> <a href="85748?version=1&table=Table107">2Vx</a> <br/><i>Baryogenesis lcb, mChi=10</i> <a href="85748?version=1&table=Table108">2Vx</a> <a href="85748?version=1&table=Table109">1Vx</a> <a href="85748?version=1&table=Table110">Combined</a> <br/><i>Baryogenesis lcb, mChi=30</i> <a href="85748?version=1&table=Table111">2Vx</a> <a href="85748?version=1&table=Table112">1Vx</a> <a href="85748?version=1&table=Table113">Combined</a> <br/><i>Baryogenesis lcb, mChi=50</i> <a href="85748?version=1&table=Table114">2Vx</a> <a href="85748?version=1&table=Table115">1Vx</a> <a href="85748?version=1&table=Table116">Combined</a> <br/><i>Baryogenesis lcb, mChi=100</i> <a href="85748?version=1&table=Table117">2Vx</a> <br/><i>Baryogenesis tatanu, mChi=10</i> <a href="85748?version=1&table=Table118">2Vx</a> <br/><i>Baryogenesis tatanu, mChi=30</i> <a href="85748?version=1&table=Table119">2Vx</a> <br/><i>Baryogenesis tatanu, mChi=50</i> <a href="85748?version=1&table=Table120">2Vx</a> <br/><i>Baryogenesis tatanu, mChi=100</i> <a href="85748?version=1&table=Table121">2Vx</a>

Barrel Muon RoI Cluster trigger efficiencies (in %) for $m_{\Phi}=100$ GeV scalar benchmark samples. The trigger efficiency is defined as the fraction of LLPs selected by the Muon RoI Cluster trigger as a function of the LLP decay position. The trigger is efficient for hadronic decays of LLPs that occur anywhere from the outer regions of the HCal to the middle station of the MS. These efficiencies are obtained from the subset of events with only a single LLP decay in the muon spectrometer in order to ensure that the result of the trigger is due to a single burst of MS activity. The uncertainties shown are statistical only. The relative differences in efficiencies of the benchmark samples are a result of the different kinematics.

Barrel Muon RoI Cluster trigger efficiencies (in %) for $m_{\Phi}=125$ GeV scalar benchmark samples. The trigger efficiency is defined as the fraction of LLPs selected by the Muon RoI Cluster trigger as a function of the LLP decay position. The trigger is efficient for hadronic decays of LLPs that occur anywhere from the outer regions of the HCal to the middle station of the MS. These efficiencies are obtained from the subset of events with only a single LLP decay in the muon spectrometer in order to ensure that the result of the trigger is due to a single burst of MS activity. The uncertainties shown are statistical only. The relative differences in efficiencies of the benchmark samples are a result of the different kinematics.

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Measurements of $\mathrm{t\overline{t}}$ differential cross sections in proton-proton collisions at $\sqrt{s} =$ 13 TeV using events containing two leptons

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 02 (2019) 149, 2019.
Inspire Record 1703993 DOI 10.17182/hepdata.89307

Measurements of differential top quark pair $\mathrm{t\overline{t}}$ cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the $\mathrm{t\overline{t}}$ system, and the total number of jets in the event. The differential cross sections are defined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract $\mathrm{t\overline{t}}$ and leptonic charge asymmetries.

188 data tables

Measured absolute differential cross section at parton level as a function of $p_{T}^{t}$.

Covariance matrix of the absolute differential cross section at parton level as a function of $p_{T}^{t}$.

Measured normalised differential cross section at parton level as a function of $p_{T}^{t}$.

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Experimental study of the $\gamma p\rightarrow K^0\Sigma^+$, $\gamma n\rightarrow K^0\Lambda$, and $\gamma n\rightarrow K^0 \Sigma^0$ reactions at the Mainz Microtron

The A2 collaboration Akondi, C.S. ; Bantawa, K. ; Manley, D.M. ; et al.
Eur.Phys.J.A 55 (2019) 202, 2019.
Inspire Record 1703675 DOI 10.17182/hepdata.130236

This work measured $d\sigma/d\Omega$ for neutral kaon photoproduction reactions from threshold up to a c.m.\ energy of 1855MeV, focussing specifically on the $\gamma p\rightarrow K^0\Sigma^+$, $\gamma n\rightarrow K^0\Lambda$, and $\gamma n\rightarrow K^0 \Sigma^0$ reactions. Our results for $\gamma n\rightarrow K^0 \Sigma^0$ are the first-ever measurements for that reaction. These data will provide insight into the properties of $N^*$ resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $\pi N$ channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

28 data tables

Total cross section as a function of c.m. energy W.

Total cross section as a function of c.m. energy W.

Total cross section as a function of c.m. energy W.

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Search for new particles decaying to a jet and an emerging jet

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 02 (2019) 179, 2019.
Inspire Record 1700173 DOI 10.17182/hepdata.88380

A search is performed for events consistent with the pair production of a new heavy particle that acts as a mediator between a dark sector and normal matter, and that decays to a light quark and a new fermion called a dark quark. The search is based on data corresponding to an integrated luminosity of 16.1 fb$^{-1}$ from proton-proton collisions at $\sqrt{s} =$ 13 TeV collected by the CMS experiment at the LHC in 2016. The dark quark is charged only under a new quantum-chromodynamics-like force, and forms an "emerging jet" via a parton shower, containing long-lived dark hadrons that give rise to displaced vertices when decaying to standard model hadrons. The data are consistent with the expectation from standard model processes. Limits are set at 95% confidence level excluding dark pion decay lengths between 5 and 225 mm for dark mediators with masses between 400 and 1250 GeV. Decay lengths smaller than 5 mm and greater than 225 mm are also excluded in the lower part of this mass range. The dependence of the limit on the dark pion mass is weak for masses between 1 and 10 GeV. This analysis is the first dedicated search for the pair production of a new particle that decays to a jet and an emerging jet.

10 data tables

Distributions of $\langle IP_{\mathrm{2D}}\rangle$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion proper decay length of 25 mm, for various dark pion masses.

Distributions of $\alpha_\mathrm{3D}$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion mass of 5 GeV for dark pion proper decay lengths ranging from 1 to 300 mm.

The signal acceptance A, defined as the fraction of simulated signal events passing the selection criteria, for models with a dark pion mass $m_{\pi_\mathrm{DK}}$ of 5 GeV as a function of the mediator mass $m_{\mathrm{X_{DK}}}$ and the dark pion proper decay length $c\tau_{\pi_\mathrm{DK}}$. The corresponding selection set number for each model is indicated as text on the plot.

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Measurement of the $ Z\gamma \to \nu \overline{\nu}\gamma $ production cross section in pp collisions at $ \sqrt{s}=13 $ TeV with the ATLAS detector and limits on anomalous triple gauge-boson couplings

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 12 (2018) 010, 2018.
Inspire Record 1698006 DOI 10.17182/hepdata.83965

The production of $Z$ bosons in association with a high-energy photon ($Z\gamma$ production) is studied in the neutrino decay channel of the $Z$ boson using $pp$ collisions at $\sqrt{s}$ = 13 TeV. The analysis uses a data sample with an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS detector at the LHC in 2015 and 2016. Candidate $Z\gamma$ events with invisible decays of the $Z$ boson are selected by requiring significant transverse momentum ($p_{T}$) of the dineutrino system in conjunction with a single isolated photon with large transverse energy ($E_{T}$). The rate of $Z\gamma$ production is measured as a function of photon $E_{T}$, dineutrino system $p_{T}$ and jet multiplicity. Evidence of anomalous triple gauge-boson couplings is sought in $Z\gamma$ production with photon $E_{T}$ greater than 600 GeV. No excess is observed relative to the Standard Model expectation, and upper limits are set on the strength of $ZZ\gamma$ and $Z\gamma\gamma$ couplings.

8 data tables

Measured integrated cross sections for the $Z\gamma$ process for neutrino final states at $\sqrt{s} = 13$ TeV in the extended fiducial region defined in the paper.

Measured differential cross sections for the $pp \rightarrow \nu\bar{\nu}\gamma$ process at $\sqrt{s} = 13$ TeV as a function of photon $E_{T}$ in the inclusive $N_{jets} \geq 0$ extended fiducial region defined in the paper.

Measured differential cross sections for the $pp \rightarrow \nu\bar{\nu}\gamma$ process at $\sqrt{s} = 13$ TeV as a function of photon $E_{T}$ in the exclusive $N_{jets} = 0$ extended fiducial region defined in the paper.

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Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 797 (2019) 134826, 2019.
Inspire Record 1697838 DOI 10.17182/hepdata.95242

Evidence for the light-by-light scattering process, $\gamma\gamma$ $\to$ $\gamma\gamma$, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390 $\mu$b$^{-1}$ recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy E$_\mathrm{T}^{\gamma}$ $>$ 2 GeV, pseudorapidity $|\eta^{\gamma}|$ $\lt$ 2.4, diphoton invariant mass $m^{\gamma\gamma}$ $\gt$ 5 GeV, diphoton transverse momentum $p_\mathrm{T}^{\gamma\gamma}$ $\lt$ 1 GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0 $\pm$ 0.9 (theo) events for the signal and 4.0 $\pm$ 1.2 (stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, $\sigma_\mathrm{fid} (\gamma\gamma$ $\to$ $\gamma\gamma) =$ 120 $\pm$ 46 (stat) $\pm$ 28 (syst) $\pm$ 12 (theo) nb, is consistent with the standard model prediction. The $m^{\gamma\gamma}$ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the $\gamma\gamma$ $\to$ a $\to$ $\gamma\gamma$ process, in the mass range $m_{\mathrm{a}} =$ 5-90 GeV.

8 data tables

Detector-level diphoton acoplanarity distribution

Detector-level photon E$_{T}$ distribution

Detector-level photon $\eta$ distribution

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Search for top quark partners with charge 5/3 in the same-sign dilepton and single-lepton final states in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 03 (2019) 082, 2019.
Inspire Record 1697570 DOI 10.17182/hepdata.85767

A search for the pair production of heavy fermionic partners of the top quark with charge 5/3 (X$_{5/3}$) is performed in proton-proton collisions at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. The data sample analyzed corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The X$_{5/3}$ quark is assumed always to decay into a top quark and a W boson. Both the right-handed and left-handed X$_{5/3}$ couplings to the W boson are considered. Final states with either a pair of same-sign leptons or a single lepton are studied. No significant excess of events is observed above the expected standard model background. Lower limits at 95% confidence level on the X$_{5/3}$ quark mass are set at 1.33 and 1.30 TeV respectively for the case of right-handed and left-handed couplings to W bosons in a combination of the same-sign dilepton and single-lepton final states.

19 data tables

Summary of yields from simulated prompt same-sign dilepton (SSP MC), same-sign nonprompt (Nonprompt), and opposite-sign prompt (ChargeMisID) backgrounds after the full analysis selection. Also shown are the number of expected events for an RH $X_{5/3}$ particle with a mass of 1 TeV. The uncertainties include both statistical and all systematic components (as described in Section 8). The number of events and uncertainties correspond to the background- only fit to data for the background, while for the signal they are based on the yields before the fit to data.

Distributions of $\min[M(\ell,\mathrm{b})]$ in the $\mathrm{t\overline{t}}$ control region, for 1 b-tagged jet category. Example signal distributions are also shown. The background distributions correspond to background-only fit to data while signal distributions are before the fit to data. Electron and muon event samples are combined. The last bin includes overflow events and its content is divided by the bin width. The distributions in each category have variable-size bins, chosen so that the statistical uncertainty in the total background in each bin is less than 30%. The lower panel in each plot shows the difference between the observed and the predicted numbers of events in that bin divided by the total uncertainty. The total uncertainty is calculated as the sum in quadrature of the statistical uncertainty in the observed measurement and the statistical and systematic uncertainties in the background-only fit to data.

Distributions of $\min[M(\ell,\mathrm{b})]$ in the $\mathrm{t\overline{t}}$ control region, for 2 or more b-tagged jet category. Example signal distributions are also shown. The background distributions correspond to background-only fit to data while signal distributions are before the fit to data. Electron and muon event samples are combined. The last bin includes overflow events and its content is divided by the bin width. The distributions in each category have variable-size bins, chosen so that the statistical uncertainty in the total background in each bin is less than 30%. The lower panel in each plot shows the difference between the observed and the predicted numbers of events in that bin divided by the total uncertainty. The total uncertainty is calculated as the sum in quadrature of the statistical uncertainty in the observed measurement and the statistical and systematic uncertainties in the background-only fit to data.

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Search for heavy Majorana or Dirac neutrinos and right-handed $W$ gauge bosons in final states with two charged leptons and two jets at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 01 (2019) 016, 2019.
Inspire Record 1696330 DOI 10.17182/hepdata.83786

A search for heavy right-handed Majorana or Dirac neutrinos $N_R$ and heavy right-handed gauge bosons $W_R$ is performed in events with a pair of energetic electrons or muons, with the same or opposite electric charge, and two energetic jets. The events are selected from $pp$ collision data with an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS detector at $\sqrt{s}$ = 13 TeV. No significant deviations from the Standard Model are observed. The results are interpreted within the theoretical framework of a left-right symmetric model and lower limits are set on masses in the heavy right-handed $W$ boson and neutrino mass plane. The excluded region extends to $m_{W_R}=4.7$ TeV for both Majorana and Dirac $N_R$ neutrinos.

20 data tables

Expected 95% CL exclusion contour in the $m_{W_R}–m_{N_R}$ plane for the Majorana $N_R$ neutrino $ee$ channel.

Observed 95% CL exclusion contour in the $m_{W_R}–m_{N_R}$ plane for the Majorana $N_R$ neutrino $ee$ channel.

Observed and expected 95% CL exclusion, for the tested signal mass hypotheses in the $m_{W_R}–m_{N_R}$ plane, for the Majorana $N_R$ neutrino $ee$ channel.

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Search for leptoquarks coupled to third-generation quarks in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 241802, 2018.
Inspire Record 1694381 DOI 10.17182/hepdata.85765

Three of the most significant measured deviations from standard model predictions, the enhanced decay rate for B $\to$ D$^{(*)}\tau\nu$, hints of lepton universality violation in B $\to$ K$^{(*)}\ell\ell$ decays, and the anomalous magnetic moment of the muon, can be explained by the existence of leptoquarks (LQs) with large couplings to third-generation quarks and masses at the TeV scale. The existence of these states can be probed at the LHC in high energy proton-proton collisions. A novel search is presented for pair production of LQs coupled to a top quark and a muon using data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$, recorded by the CMS experiment. No deviation from the standard model prediction has been observed and scalar LQs decaying exclusively into t$\mu$ are excluded up to masses of 1420 GeV. The results of this search are combined with those from previous searches for LQ decays into t$\tau$ and b$\nu$, which excluded scalar LQs below masses of 900 and 1080 GeV. Vector LQs are excluded up to masses of 1190 GeV for all possible combinations of branching fractions to t$\mu$, t$\tau$ and b$\nu$. With this analysis, all relevant couplings of LQs with an electric charge of -1/3 to third-generation quarks are probed for the first time.

6 data tables

Distributions for $M_{LQ}^{rec}$ (category A) after applying the full selection. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Distributions for $S_{T}$ (category B) after applying the full selection and estimating the $t\overline{t}$ and DY+jets background contributions from data in category B. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Observed upper limits on the production cross section for pair production of LQs decaying into a top quark and a muon or a $\tau$ lepton at 95% CL in the $M_{LQ} - B(LQ \rightarrow t\mu)$ plane.

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Observation of Higgs boson decay to bottom quarks

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 121801, 2018.
Inspire Record 1691854 DOI 10.17182/hepdata.86132

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, are described. When combined with previous VH measurements using data collected at $\sqrt{s}=$ 7, 8, and 13 TeV, an excess of events is observed at $m_\mathrm{H} =$ 125.09 GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01 $\pm$ 0.22. The combination of this result with searches by the CMS experiment for H $\to\mathrm{b\overline{b}}$ in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04 $\pm$ 0.20.

2 data tables

Expected and observed significances, in number of standard deviations, and observed signal strengths for the VH production process with H-->b bbar. Results are shown separately for 2017 data, combined Run 2 (2016 and 2017 data), and for the combination of the Run 1 and Run 2 data. For the 2017 analysis, results are shown separately for the individual mu value for each channel from a combined simultaneous fit to all channels. All results are obtained for mH=125.09 GeV. Data are from Table 2 and 2016 added from Figure 1b.

Best-fit value of the H-->b bbar signal strength with its 1 sigma systematic (red) and total (blue) uncertainties for the five individual production modes considered, as well as the overall combined result. The vertical dashed line indicates the standard model expectation. All results are extracted from a single fit combining all input analyses, with mH = 125.09 GeV. Data from Figure 3.