Date

Search for the production of a long-lived neutral particle decaying within the ATLAS hadronic calorimeter in association with a $Z$ boson from $pp$ collisions at $\sqrt{s} = 13$ TeV

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.Lett. 122 (2019) 151801, 2019.
Inspire Record 1702261 DOI 10.17182/hepdata.83963

This Letter presents a search for the production of a long-lived neutral particle ($Z_d$) decaying within the ATLAS hadronic calorimeter, in association with a Standard Model (SM) $Z$ boson produced via an intermediate scalar boson, where $Z\to l^+l^-$ ($l=e,\mu$). The data used were collected by the ATLAS detector during 2015 and 2016 $pp$ collisions with a center-of-mass energy of $\sqrt{s} = 13$ TeV at the Large Hadron Collider and corresponds to an integrated luminosity of $36.1\pm0.8$ fb$^{-1}$. No significant excess of events is observed above the expected background. Limits on the production cross section of the scalar boson times its decay branching fraction into the long-lived neutral particle are derived as a function of the mass of the intermediate scalar boson, the mass of the long-lived neutral particle, and its $c\tau$ from a few centimeters to one hundred meters. In the case that the intermediate scalar boson is the SM Higgs boson, its decay branching fraction to a long-lived neutral particle with a $c\tau$ approximately between 0.1 m and 7 m is excluded with a 95% confidence level up to 10% for $m_{Z_d}$ between 5 and 15 GeV.

1 data table

The product of acceptance and efficiency for all signal MC samples.


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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Search for long-lived particles decaying into displaced jets in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.D 99 (2019) 032011, 2019.
Inspire Record 1704319 DOI 10.17182/hepdata.88880

A search for long-lived particles decaying into jets is presented. Data were collected with the CMS detector at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The search examines the distinctive topology of displaced tracks and secondary vertices. The selected events are found to be consistent with standard model predictions. For a simplified model in which long-lived neutral particles are pair produced and decay to two jets, pair production cross sections larger than 0.2 fb are excluded at 95% confidence level for a long-lived particle mass larger than 1000 GeV and proper decay lengths between 3 and 130 mm. Several supersymmetry models with gauge-mediated supersymmetry breaking or $R$-parity violation, where pair-produced long-lived gluinos or top squarks decay to several final-state topologies containing displaced jets, are also tested. For these models, in the mass ranges above 200 GeV, gluino masses up to 2300-2400 GeV and top squark masses up to 1350-1600 GeV are excluded for proper decay lengths approximately between 10 and 100 mm. These are the most restrictive limits to date on these models.

18 data tables

The distributions of vertex track multiplicity for data, simulated QCD multijet events, and simulated signal events. Data and simulated events are selected with the displaced-jet trigger. The offline $H_{T}$ is required to be larger than 400 $\mathrm{GeV}$, and the jets are required to have $p_{T}>50\ \mathrm{GeV}$ and $|\eta|<2.0$. Three benchmark signal distributions are shown (dashed lines) for the jet-jet model with $m_{X}=300\ \mathrm{GeV}$ and varying lifetimes. For visualization each signal process is given a cross section, $\sigma$, such that $\sigma\ 35.9\ \mathrm{fb}^{-1} = 1 \times 10^{6}$.

The distributions of vertex $L_{xy}$ significance for data, simulated QCD multijet events, and simulated signal events. Data and simulated events are selected with the displaced-jet trigger. The offline $H_{T}$ is required to be larger than 400 $\mathrm{GeV}$, and the jets are required to have $p_{T}>50\mathrm{GeV}$ and $|\eta|<2.0$. Three benchmark signal distributions are shown (dashed lines) for the jet-jet model with $m_{X}=300\ \mathrm{GeV}$ and varying lifetimes. For visualization each signal process is given a cross section, $\sigma$, such that $\sigma\ 35.9 \mathrm{fb}^{-1} = 1 \times 10^{6}$.

The distributions of cluster RMS for data, simulated QCD multijet events, and simulated signal events. Data and simulated events are selected with the displaced-jet trigger. The offline $H_{T}$ is required to be larger than 400 $\mathrm{GeV}$, and the jets are required to have $p_{T}>50\ \mathrm{GeV}$ and $|\eta|<2.0$. Three benchmark signal distributions are shown (dashed lines) for the jet-jet model with $m_{X}=300\ \mathrm{GeV}$ and varying lifetimes. For visualization each signal process is given a cross section, $\sigma$, such that $\sigma\ 35.9\ \mathrm{fb}^{-1} = 1 \times 10^{6}$.

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Jet fragmentation transverse momentum measurements from di-hadron correlations in $\sqrt{s}$ = 7 TeV pp and $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV p-Pb collisions

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
JHEP 03 (2019) 169, 2019.
Inspire Record 1704923 DOI 10.17182/hepdata.89304

The transverse structure of jets was studied via jet fragmentation transverse momentum ($j_{\rm{T}}$) distributions, obtained using two-particle correlations in proton-proton and proton-lead collisions, measured with the ALICE experiment at the LHC. The highest transverse momentum particle in each event is used as the trigger particle and the region $3 < p_{\rm{Tt}} < 15$ GeV/$c$ is explored in this study. The measured distributions show a clear narrow Gaussian component and a wide non-Gaussian one. Based on Pythia simulations, the narrow component can be related to non-perturbative hadronization and the wide component to quantum chromodynamical splitting. The width of the narrow component shows a weak dependence on the transverse momentum of the trigger particle, in agreement with the expectation of universality of the hadronization process. On the other hand, the width of the wide component shows a rising trend suggesting increased branching for higher transverse momentum. The results obtained in pp collisions at $\sqrt{s}$ = 7 TeV and in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV are compatible within uncertainties and hence no significant cold nuclear matter effects are observed. The results are compared to previous measurements from CCOR and PHENIX as well as to Pythia 8 and Herwig 7 simulations.

24 data tables

trigger particle momentum dependence of observables RMS for narrow component in p-p collisions at 7 TeV with 0.2<xlong<0.4.

trigger particle momentum dependence of observables RMS for narrow component in p-p collisions at 7 TeV with 0.4<xlong<0.6.

trigger particle momentum dependence of observables RMS for narrow component in p-p collisions at 7 TeV with 0.6<xlong<1.0.

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Measurements of fiducial and differential cross-sections of $t\bar{t}$ production with additional heavy-flavour jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 04 (2019) 046, 2019.
Inspire Record 1705857 DOI 10.17182/hepdata.87098

This paper presents measurements of $t\bar{t}$ production in association with additional $b$-jets in $pp$ collisions at the LHC at a centre-of-mass energy of 13 TeV. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb$^{-1}$. Fiducial cross-section measurements are performed in the dilepton and lepton-plus-jets $t\bar{t}$ decay channels. Results are presented at particle level in the form of inclusive cross-sections of $t\bar{t}$ final states with three and four $b$-jets as well as differential cross-sections as a function of global event properties and properties of $b$-jet pairs. The measured inclusive fiducial cross-sections generally exceed the $t\bar{t}b\bar{b}$ predictions from various next-to-leading-order matrix element calculations matched to a parton shower but are compatible within the total uncertainties. The experimental uncertainties are smaller than the uncertainties in the predictions. Comparisons of state-of-the-art theoretical predictions with the differential measurements are shown and good agreement with data is found for most of them.

50 data tables

The measured fiducial cross sections

The measured fiducial cross sections

Relative differential cross section as a function of the b-jet multiplicity in emu channel

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Study of J/$\psi$ azimuthal anisotropy at forward rapidity in Pb-Pb collisions at $\sqrt{{\textit s}_{\rm NN}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
JHEP 02 (2019) 012, 2019.
Inspire Record 1706006 DOI 10.17182/hepdata.88308

The second ($v_2$) and third ($v_3$) flow harmonic coefficients of J/$\psi$ mesons are measured at forward rapidity (2.5 $<$ $y$ $<$ 4.0) in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the LHC. Results are obtained with the scalar product method and reported as a function of transverse momentum, $p_{\rm{T}}$, for various collision centralities. A positive value of J/$\psi$ $v_3$ is observed with 3.7$\sigma$ significance. The measurements, compared to those of prompt D$^0$ mesons and charged particles at mid-rapidity, indicate an ordering with $v_{\rm n}$(J/$\psi$) $

12 data tables

The J/$\psi$ $v_2$ coefficient as a function of $p_{\rm T}$ in 0-10% centrality interval in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

The J/$\psi$ $v_2$ coefficient as a function of $p_{\rm T}$ in 10-30% centrality interval in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

The J/$\psi$ $v_2$ coefficient as a function of $p_{\rm T}$ in 30-50% centrality interval in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

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Measurements of inclusive and differential fiducial cross-sections of $t\bar{t}\gamma$ production in leptonic final states at $\sqrt{s}$ = 13 TeV in ATLAS

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Eur.Phys.J.C 79 (2019) 382, 2019.
Inspire Record 1707015 DOI 10.17182/hepdata.88061

Inclusive and differential cross-sections for the production of a top-quark pair in association with a photon are measured with proton-proton collision data corresponding to an integrated luminosity of 36.1 fb$^{-1}$, collected by the ATLAS detector at the LHC in 2015 and 2016 at a centre-of-mass energy of 13 TeV. The measurements are performed in single-lepton and dilepton final states in a fiducial volume. Events with exactly one photon, one or two leptons, a channel-dependent minimum number of jets, and at least one $b$-jet are selected. Neural network algorithms are used to separate the signal from the backgrounds. The fiducial cross-sections are measured to be 521 $\pm$ 9(stat.) $\pm$ 41(sys.) fb and 69 $\pm$ 3(stat.) $\pm$ 4(sys.) fb for the single-lepton and dilepton channels, respectively. The differential cross-sections are measured as a function of photon transverse momentum, photon absolute pseudorapidity, and angular distance between the photon and its closest lepton in both channels, as well as azimuthal opening angle and absolute pseudorapidity difference between the two leptons in the dilepton channel. All measurements are in agreement with the theoretical predictions.

20 data tables

The measured fiducial cross section in the single lepton channel. The first uncertainty is the statistical uncertainty and the second one is the systematic uncertainty.

The measured fiducial cross section in the dilepton channel. The first uncertainty is the statistical uncertainty and the second one is the systematic uncertainty.

The measured normalized differential cross section as a function of the photon pT in the single lepton channel. The uncertainty is decomposed into five components which are the signal modelling uncertainty, the experimental uncertainty, the ttbar modelling uncertainty, the other background estimation uncertainty, and the data statistical uncertainty.

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Charged-particle pseudorapidity density at mid-rapidity in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 8.16 TeV

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
Eur.Phys.J.C 79 (2019) 307, 2019.
Inspire Record 1706753 DOI 10.17182/hepdata.89268

The pseudorapidity density of charged particles, $\rm{d}\it{N}_\rm{ch}/\rm{d}\it{\eta}$, in p-Pb collisions has been measured at a centre-of-mass energy per nucleon-nucleon pair of $\sqrt{s_{\rm{NN}}}$ = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, $|\eta|<1.8$. The $\rm{d}\it{N}_\rm{ch}/\rm{d}\it{\eta}$ value is $19.1\pm0.7$ at $|\eta|<0.5$. This quantity divided by $\langle N_\rm{part} \rangle/2$, is $4.73\pm0.20$, which is 9.5% higher than the corresponding value for p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the $\rm{d}\it{N}_\rm{ch}/\rm{d}\it{\eta}$ distribution. Saturation-based models reproduce the distributions well for $\eta>-1.3$. The $\rm{d}\it{N}_\rm{ch}/\rm{d}\it{\eta}$ is also measured for different centrality estimators, based both on the charged-particle multiplicity and on the energy deposited in the Zero-Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p-Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity.

29 data tables

Pseudorapidity density of charged particles in p–Pb NSD collisions at a centre-of-mass energy of 8.16 TeV.

Values of average pseudorapidity density of charged particles in p–Pb NSD collisions as a function of the energy in the centre-of-mass.

Pseudorapidity density of charged particles in p–Pb NSD collisions at 8.16 TeV for 0-5% centrality class and CL1 estimator.

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Search for heavy long-lived multi-charged particles in proton-proton collisions at $\sqrt{s}$ = 13 TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.D 99 (2019) 052003, 2019.
Inspire Record 1707957 DOI 10.17182/hepdata.85615

A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data with an integrated luminosity of 36.1 fb$^{-1}$ collected in 2015 and 2016 from proton-proton collisions at $\sqrt{s}$ = 13 TeV are examined. Particles producing anomalously high ionization, consistent with long-lived massive particles with electric charges from |q|=2e to |q|=7e, are searched for. No events are observed, and 95% confidence level cross-section upper limits are interpreted as lower mass limits for a Drell-Yan production model. Multi-charged particles with masses between 50 GeV and 980-1220 GeV (depending on their electric charge) are excluded.

3 data tables

The signal efficiency values versus mass values for different charges.

Expected cross-section upper limits on the production cross-section of MCPs as a function of simulated particle mass for different charges.

Observed cross-section upper limits on the production cross-section of MCPs as a function of simulated particle mass for different charges.


Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two muons and two b quarks in pp collisions at 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 795 (2019) 398-423, 2019.
Inspire Record 1709317 DOI 10.17182/hepdata.91235

A search for exotic decays of the Higgs boson to a pair of light pseudoscalar particles a$_1$ is performed under the hypothesis that one of the pseudoscalars decays to a pair of opposite sign muons and the other decays to b$\overline{\mathrm{b}}$. Such signatures are predicted in a number of extensions of the standard model (SM), including next-to-minimal supersymmetry and two-Higgs-doublet models with an additional scalar singlet. The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated with the CMS experiment at the CERN LHC in 2016 at a centre-of-mass energy of 13 TeV. No statistically significant excess is observed with respect to the SM backgrounds in the search region for pseudoscalar masses from 20 GeV to half of the Higgs boson mass. Upper limits at 95% confidence level are set on the product of the production cross section and branching fraction, $\sigma_{\mathrm{h}}\mathcal{B}$(h $\to$ a$_1$ a$_1$ $\to$ $\mu^+\mu^-\mathrm{b}\bar{\mathrm{b}}$), ranging from 5 to 33 fb, depending on the pseudoscalar mass. Corresponding limits on the branching fraction, assuming the SM prediction for $\sigma_{\mathrm{h}}$, are (1$-$7)$\times$ 10$^{-4}$.

2 data tables

Observed and expected upper limits at 95% CL on the product of the Higgs boson production cross section and B(h->aa->mumubb)

Observed and expected upper limits at 95% CL on the branching fraction of (h->aa->mumubb)