# Haut PDF Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC.

### Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC.

Sampling 3 1.5 < |η| < 2.5 0.05 × 0.025 Table 3.1: Detailed granularity and pseudorapidity coverage of the ATLAS ECAL. 3.2.1 ECAL readout system The LAr calorimeter (ECAL, HEC, and FCAL) has an uniform readout architecture, whose block diagram is shown in figure 3.8 [ 37 ]. The electric signals produced in the cells are processed by electronic boards called ”front end boards” (FEB), which are mounted directly on the detector cryostat. Each of the 1524 FEBs processes the signal from up to 128 channels. The original triangular-shaped pulse produced in the electrodes is first amplified by a preamplifier array. The output of the preamplifier is then shaped and amplified again, splitting it into three gain scales (1-10-100). The signal is then sampled and stored during the LVL1 latency (up to 25 ns). When a positive LVL1 decision arrives, the signal is digitized in a 12 bits analog to digital converter (ADC), and the data sent via an optical link to the readout drivers electronic boards (ROD) [ 38 ].
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### Measurement of the double-differential high-mass Drell-Yan cross section in pp collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

equation ( 1 ) now corresponds to electrons that pass the loose requirements but fail the requirement on the matching between track and cluster, instead of failing the full identification and isolation requirements. In addition, two alternative background-enriched samples are obtained using a tag-and-probe technique on the jet-triggered sample and on the sample triggered by the default analysis triggers, requiring the tag to fail certain aspects of the electron identification depending on the trigger. Furthermore, the event should have a missing transverse momentum smaller than 25 GeV, the probe needs to have the same charge as the tag and the invariant mass of the tag-and-probe pair needs to be outside the Z mass window from 71 to 111 GeV.
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### Measurement of the transverse momentum distribution of Z/gamma* bosons in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS detector

T values in the range of 10 GeV to 40 GeV and slightly lower above 40 GeV. The Alpgen [ 19 ] and Sherpa [ 20 ] generators consider processes with up to five additional hard partons associ- ated with the produced boson and give a good descrip- tion of the entire measured spectrum, up to large p Z T , with χ 2 /d.o.f. of 31.9/19 and 16.8/19, respectively. Here, the enhancement of the cross section compared to the O(α 2 S ) prediction can be attributed to processes with large parton multiplicities [ 52 ], which correspond to tree-level diagrams of higher order in the strong coupling. Sherpa v1.2.3 and Alpgen v2.13 are used, with the latter being interfaced to Herwig v6.510 [ 16 ] for parton shower and fragmentation into particles, and to Jimmy v4.31 [ 32 ] to model underly- ing event contributions. For Alpgen, the CTEQ6L1 [ 53 ] PDF set is employed and the factorization scale is set to µ 2
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### Measurement of the associated production of a Higgs boson decaying into $b$-quarks with a vector boson at high transverse momentum in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

Table 1: Signal and background processes with the corresponding generators used for the nominal samples. If not specified, the order of the cross-section calculation refers to the expansion in the strong coupling constant (𝛼 S ). (★) The events were generated using the first PDF in the NNPDF3.0NLO set and subsequently reweighted to the PDF4LHC15NLO set [ 38 ] using the internal algorithm in Powheg-Box v2. (†) The NNLO(QCD)+NLO(EW) cross-section calculation for the 𝑝 𝑝 → 𝑍 𝐻 process already includes the 𝑔𝑔 → 𝑍 𝐻 contribution. The 𝑞𝑞 → 𝑍 𝐻 process is normalised using the cross-section for the 𝑝 𝑝 → 𝑍 𝐻 process, after subtracting the 𝑔𝑔 → 𝑍 𝐻 contribution. An additional scale factor is applied to the 𝑞𝑞 → 𝑉 𝐻 processes as a function of the transverse momentum of the vector boson, to account for electroweak (EW) corrections at NLO. This makes use of the 𝑉 𝐻 differential cross-section computed with Hawk [ 39 , 40 ].
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### Measurements of the production cross-section for a $Z$ boson in association with $b$-jets in proton-proton collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The measurements are compared with predictions from a variety of Monte Carlo generators. In general, 5-flavour number scheme (5FNS) calculations at NLO accuracy predict the inclusive cross-sections well, while inclusive 4-flavour number scheme (4FNS) LO calculations largely underestimate the data. Predictions of Z bb at NLO accuracy agree with data only in the two-b-jets case, and underestimate the data in the case of events with at least one b-jet. Overall, Sherpa 5FNS (NLO), a 5FNS generator with matrix elements at NLO for up to two partons and matrix elements at LO for up to four partons, describes the various differential distributions within the experimental uncertainties. A significant discrepancy, common to all generators, is found for large values of m bb . The Sherpa Fusing 4FNS+5FNS (NLO) simulation, which combines 4FNS with 5FNS at NLO accuracy using a novel technique, agrees with Sherpa 5FNS (NLO), showing that in general at the scales tested by this measurement the effects of this merging are minor. A disagreement of about 20 30% is observed for large values of the leading b-jet transverse momentum, and for small angular separations between the Z boson and the leading b-jet. The 5FNS simulation with matrix elements for up to four partons at LO, as implemented in MGaMC + Py8 (LO), describes the data within the experimental uncertainties in most cases. In some cases this simulation is even better than predictions from MGaMC + Py8 5FNS (NLO), which has matrix elements with only one parton at NLO. This indicates the importance of simulations with several partons in the matrix element for a fair description of the data. The pure Z bb simulation at NLO in the 4FNS, as generated by Sherpa and MGaMC, shows significant deviations from the data even in the two-b-jets configuration, and this is more pronounced in MGaMC.
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### Measurement of the production cross-section of a single top quark in association with a Z boson in proton–proton collisions at 13 TeV with the ATLAS detector

3 Data and simulation samples The pp collision data sample used in this measurement was collected with the ATLAS detector at the LHC during the 2015 and 2016 data-taking periods, corresponding to integrated luminosities of 3.3 fb −1 and 32.8 fb −1 , respectively, for a total of 36.1 fb −1 , after requiring that the detector is fully operational. Events are considered if they were accepted by at least one of the single-muon or single-electron triggers [ 17 , 18 ]. The electron triggers select a cluster in the calorimeter matched to a track. Electrons must then satisfy identification criteria based on a multivariate technique using a likelihood discriminant. In 2015, electrons had to satisfy a ‘medium’ identification requirement and have a transverse energy of E T > 24 GeV. In 2016, electrons had to satisfy a ‘tight’ identification together with an isolation criterion and have E T > 26 GeV. To avoid efficiency loss due to isolation at high E T , an additional trigger was used, selecting ‘medium’ electrons with E T > 60 GeV. Muons are triggered on by matching tracks reconstructed in the muon spectrometer and in the inner detector. In 2015, muons had to satisfy a ‘loose’ isolation requirement and have a transverse momentum of p T > 20 GeV. In 2016, the isolation criteria were tightened and the threshold increased to p T = 26 GeV. In both years, another muon trigger without any isolation requirement was used, selecting muons with p T > 50 GeV.
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### Measurements of the production cross section of a $Z$ boson in association with jets in pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The systematic uncertainties on the multijet background are derived by varying the mass range and bin width of the nominal fit, using the lepton transverse impact parameter d 0 as the fitting variable instead of the invariant mass, using alternative simulation samples for the templates, allowing the normalisations of the non-multijet components to vary independently or within a wider range, and varying the lepton resolution and energy/momentum scales. In addition, given the multiple sources of multijet background in the electron channel, an alternative template is constructed by requiring that the electrons fail to meet an isolation criterion instead of failing to meet the nominal signal selection electron identification cri- terion.
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### Contributions to a first measurement of the W-boson mass in the electron channel with the ATLAS detector

In soft scattering events, one or two protons dissociate into a system of particles with low trans- verse momentum. They are dominant processes at the LHC and include diffraction, Multiple- Partonic Interactions (MPI), soft initial- and final-state radiation (ISR /FSR), and beam-beam remnants. These phenomena are grouped according to experimental trigger. For example, min- imum bias interactions are the processes that are selected with a loose trigger intended to select inelastic collisions with as little bias as possible. The Underlying Event (UE) is the collection of all the soft processes that accompany a high-transverse momentum interaction of interest. It is typically studied as a function of the highest-transverse momentum particle in the event. On the other hand, in the hard scattering events, like Drell-Yan processes, Higgs production, etc., high transverse momentum particles are produced. The rates and properties for the hard pro- cesses can be predicted with good precision using the perturbation theory, due to the asymptotic freedom property where quarks interact as free particles at large energy scales.
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### Measurement of the cross section of high transverse momentum $Z\rightarrow b\bar{b}$ production in proton--proton collisions at $\sqrt{s}=8 TeV$ with the ATLAS Detector

1. Introduction High transverse momentum (p T ), hadronically decaying, electroweak-scale bosons have already been used in searches at the LHC [1–5], and are expected to play an increasingly signif- icant role as the LHC moves to higher centre-of-mass energies in 2015. Therefore it is important to study them directly. This Letter presents the observation of a high-p T Z → bb signal in a fully hadronic final state, and a measurement of its production cross section. The measurement is compared to the next-to- leading-order (NLO) matrix element plus parton-shower pre- dictions of POWHEG [6–9] and aMC@NLO [10], where the parton-shower, hadronisation and underlying-event modelling are provided by Pythia-8.165 [11] and Herwig++ [12] respec- tively. This first measurement of a high-p T electroweak-scale boson in an all-hadronic final state at the LHC demonstrates the validity of both the analysis techniques used and of the state-of-the-art NLO plus parton-shower particle-level predic- tions for electroweak-scale bosons decaying to bb. It is there- fore of great relevance for the search for the H → bb signal in the (most sensitive) high Higgs boson p T range [13], as well as for searches for TeV-scale resonances decaying to bbbb via
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### Measurement of the production cross section of jets in association with a Z boson in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

Exclusive jet multiplicities at the LHC are expected to be described by means of two benchmark patterns, ‘staircase scaling’ with R (n+1)/n constant and ‘Poisson scaling’ with R (n+1)/n inversely proportional to n [ 3 , 45 ], which provide limiting cases for certain kine- matic conditions. While for high multiplicities a flat exclusive jet multiplicity ratio is derived from the non-abelian nature of QCD FSR, at low multiplicity the jet multiplicity ratio is flat due to the combined effect of a Poisson-distributed multiplicity distribution and parton density suppression [ 3 ]. The emission of the first parton should be suppressed more strongly than the subsequent parton emissions. The underlying Poisson scaling is expected to emerge after introducing large scale differences between the core process (Z (+1 jet)) and the p jet T of the second leading jet. Two selections are chosen to test the two benchmark scenarios: (a) the standard Z + jets selection and (b) events where the leading jet has a transverse momentum in excess of 150 GeV.
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### Measurement of the $W^{\pm}Z$ boson pair-production cross section in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS Detector

certainties in the scale and resolution of the electron energy, muon momentum, jet energy and E miss T , as well as uncertainties in the scale factors applied to the simulation in order to reproduce the trigger, re- construction, identification and isolation efficiencies measured in data. The uncertainties in the jet energy scale are obtained from √ s = 13 TeV simulations and in situ measurements, similar to the ones described in Ref. [ 43 ]. The uncertainty in the jet energy resolution is derived by extrapolating measurements in Run-1 data to √ s = 13 TeV. The uncertainty in the E T miss is estimated by propagating the uncertainties in the transverse momenta of hard physics objects and by applying momentum scale and resolution uncer- tainties to the track-based soft term. The uncertainty associated with pile-up modelling is of the order of 1% and can reach up to 2.9% in the 0-jet bin of the unfolded jet multiplicity distribution. For the measure- ments of the W charge-dependent cross sections, an uncertainty arising from the charge misidentification of leptons is also considered. It a ffects only electrons and leads to an uncertainty of less than 0.05% in the ratio of W + Z to W − Z integrated cross sections determined by combining the four decay channels. The dominant contribution among the experimental systematic uncertainties in the eee and µee channels is due to the uncertainty in the electron identification e fficiency, contributing at most 1.4% uncertainty to the integrated cross section, while in the eµµ and µµµ channels it originates from the muon reconstruction efficiency and is at most 1.1%. The systematic uncertainties in the measured cross sections are determined by repeating the analysis after applying appropriate variations for each source of systematic uncertainty to the simulated samples.
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### Measurement of the differential cross-section of highly boosted top quarks as a function of their transverse momentum in $\sqrt{s}$ = 8 TeV proton-proton collisions using the ATLAS detector

an integrated luminosity of 20.3 fb −1 collected by the ATLAS detector at the LHC. Boosted hadronic- ally decaying top quarks with p T > 300 GeV are reconstructed within large-R jets and identified using jet substructure techniques. The measured p T spectrum is extended in this analysis relative to previous measurements. A particle-level cross-section is measured in a fiducial region that closely follows the event selection. The measurement uncertainty ranges from 13% to 29% and is generally dominated by the uncertainty on the jet energy scale of large-R jets. A parton-level cross-section is also reported, with larger systematic uncertainties due to its greater reliance on t¯t MC generators to correct the data. The measured cross-sections are compared to the predictions of several NLO and LO matrix-element generators normalized to NNLO+NNLL QCD calculations, and using various PDF sets. Previous measurements suggest that the top quark p T spectrum is well predicted at low p T by NLO and matrix-
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### Measurement of the cross-section for W boson production in association with b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

be on the efficiency plateau for the respective triggers. The selection efficiency of electrons and muons in simulated events, as well as their energy and momentum scale and resolution, are adjusted to reproduce those observed in Z →  events in data [ 29 – 31 ]. In order to reduce the large background from multijet production, lepton candidates are required to be isolated from neighbouring tracks within ∆R = 0.4 of their direction, as well as from other calorimeter energy depositions, corrected for pile-up contributions, within ∆R = 0.2. In the muon case, the sum of transverse momenta of neighbouring tracks must be less than 2 GeV, while the sum of the calorimeter transverse energies must be less than 1 GeV. In the electron case, these requirements range between 1.35 GeV and 3.15 GeV depending on p T and η in order to yield a constant efficiency across momentum ranges and detector regions. Additionally, leptons are required to be consistent with originating from the PV. Their longitudinal impact parameter (|z 0 |) with respect to the PV must be smaller
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### Measurement of Z boson Production in Pb+Pb Collisions at sqrt(s_NN)=2.76 TeV with the ATLAS Detector

We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Ar- gentina; YerPhI, Armenia; ARC, Australia; BMWF and FWF, Austria; ANAS, Azerbaijan; SSTC, Be- larus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET and ERC, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT, Greece; ISF, MINERVA, GIF, DIP and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW, Poland; GRICES and FCT, Portugal; MERYS (MECTS), Romania; MES of Rus- sia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MVZT, Slovenia; DST/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Can- tons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Lever- hulme Trust, United Kingdom; DOE and NSF, United States of America.
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### Measurement of the $t\bar{t}$ production cross-section as a function of jet multiplicity and jet transverse momentum in 7 TeV proton-proton collisions with the ATLAS detector

Acknowledgments We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Aus- tralia; BMWF and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET, ERC and NSRF, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT and NSRF, Greece; ISF, MIN- ERVA, GIF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW and NCN, Poland; GRICES and FCT, Portugal; MNE/IFA, Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, United Kingdom; DOE and NSF, United States of America.
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### Observation of electroweak production of two jets and a $Z$-boson pair with the ATLAS detector at the LHC

M. Campanelli 95 , A. Camplani 40 , A. Campoverde 151 , V. Canale 70a,70b , A. Canesse 104 , M. Cano Bret 60c , J. Cantero 130 , T. Cao 161 , Y. Cao 173 , M.D.M. Capeans Garrido 36 , M. Capua 41b,41a , R. Cardarelli 74a , F. Cardillo 149 , G. Carducci 41b,41a , I. Carli 143 , T. Carli 36 , G. Carlino 70a , B.T. Carlson 139 , E.M. Carlson 176,168a , L. Carminati 69a,69b , R.M.D. Carney 153 , S. Caron 119 , E. Carquin 147d , S. Carrá 46 , J.W.S. Carter 167 , M.P. Casado 14,e , A.F. Casha 167 , R. Castelijn 120 , F.L. Castillo 174 , L. Castillo Garcia 14 , V. Castillo Gimenez 174 , N.F. Castro 140a,140e , A. Catinaccio 36 , J.R. Catmore 134 , A. Cattai 36 , V. Cavaliere 29 , E. Cavallaro 14 , M. Cavalli-Sforza 14 , V. Cavasinni 72a,72b , E. Celebi 12b , L. Cerda Alberich 174 , K. Cerny 131 , A.S. Cerqueira 81a , A. Cerri 156 , L. Cerrito 74a,74b , F. Cerutti 18 , A. Cervelli 23b,23a , S.A. Cetin 12b , Z. Chadi 35a , D. Chakraborty 121 , J. Chan 181 , W.S. Chan 120 , W.Y. Chan 91 , J.D. Chapman 32 , B. Chargeishvili 159b , D.G. Charlton 21 , T.P. Charman 93 , C.C. Chau 34 , S. Che 127 , S. Chekanov 6 , S.V. Chekulaev 168a , G.A. Chelkov 80 , B. Chen 79 , C. Chen 60a , C.H. Chen 79 , H. Chen 29 , J. Chen 60a , J. Chen 39 , J. Chen 26 , S. Chen 137 , S.J. Chen 15c , X. Chen 15b , Y-H. Chen 46 , H.C. Cheng 63a , H.J. Cheng 15a , A. Cheplakov 80 , E. Cheremushkina 123 , R. Cherkaoui El Moursli 35e , E. Cheu 7 , K. Cheung 64 , T.J.A. Chevalérias 145 , L. Chevalier 145 , V. Chiarella 51 , G. Chiarelli 72a , G. Chiodini 68a , A.S. Chisholm 21 , A. Chitan 27b , I. Chiu 163 , Y.H. Chiu 176 , M.V. Chizhov 80 , K. Choi 11 , A.R. Chomont 73a,73b , S. Chouridou 162 , Y.S. Chow 120 ,
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### Measurement of differential production cross-sections for a $Z$ boson in association with $b$-jets in 7 TeV proton-proton collisions with the ATLAS detector

C. Hsu 146c , P.J. Hsu 82 , S.-C. Hsu 139 , D. Hu 35 , X. Hu 25 , Y. Huang 42 , Z. Hubacek 30 , F. Hubaut 84 , F. Huegging 21 , T.B. Huffman 119 , E.W. Hughes 35 , G. Hughes 71 , M. Huhtinen 30 , T.A. H¨ ulsing 82 , M. Hurwitz 15 , N. Huseynov 64,b , J. Huston 89 , J. Huth 57 , G. Iacobucci 49 , G. Iakovidis 10 , I. Ibragimov 142 , L. Iconomidou-Fayard 116 , E. Ideal 177 , P. Iengo 103a , O. Igonkina 106 , T. Iizawa 172 , Y. Ikegami 65 , K. Ikematsu 142 , M. Ikeno 65 , Y. Ilchenko 31,o , D. Iliadis 155 , N. Ilic 159 , Y. Inamaru 66 , T. Ince 100 , P. Ioannou 9 , M. Iodice 135a , K. Iordanidou 9 , V. Ippolito 57 , A. Irles Quiles 168 , C. Isaksson 167 , M. Ishino 67 , M. Ishitsuka 158 , R. Ishmukhametov 110 , C. Issever 119 , S. Istin 19a , J.M. Iturbe Ponce 83 , R. Iuppa 134a,134b , J. Ivarsson 80 , W. Iwanski 39 , H. Iwasaki 65 , J.M. Izen 41 , V. Izzo 103a , B. Jackson 121 , M. Jackson 73 , P. Jackson 1 , M.R. Jaekel 30 , V. Jain 2 , K. Jakobs 48 , S. Jakobsen 30 , T. Jakoubek 126 , J. Jakubek 127 , D.O. Jamin 152 , D.K. Jana 78 , E. Jansen 77 , H. Jansen 30 , J. Janssen 21 , M. Janus 171 , G. Jarlskog 80 , N. Javadov 64,b , T. Jav˚ urek 48 , L. Jeanty 15 , J. Jejelava 51a ,p , G.-Y. Jeng 151 , D. Jennens 87 , P. Jenni 48,q , J. Jentzsch 43 , C. Jeske 171 , S. J´ez´equel 5 , H. Ji 174 , J. Jia 149 , Y. Jiang 33b , M. Jimenez Belenguer 42 , S. Jin 33a , A. Jinaru 26a , O. Jinnouchi 158 , M.D. Joergensen 36 , K.E. Johansson 147a,147b , P. Johansson 140 , K.A. Johns 7 , K. Jon-And 147a,147b , G. Jones 171 , R.W.L. Jones 71 , T.J. Jones 73 , J. Jongmanns 58a , P.M. Jorge 125a,125b , K.D. Joshi 83 , J. Jovicevic 148 , X. Ju 174 , C.A. Jung 43 , R.M. Jungst 30 , P. Jussel 61 , A. Juste Rozas 12,n , M. Kaci 168 , A. Kaczmarska 39 , M. Kado 116 , H. Kagan 110 , M. Kagan 144 , E. Kajomovitz 45 , C.W. Kalderon 119 , S. Kama 40 , A. Kamenshchikov 129 , N. Kanaya 156 , M. Kaneda 30 , S. Kaneti 28 , V.A. Kantserov 97 , J. Kanzaki 65 , B. Kaplan 109 , A. Kapliy 31 , D. Kar 53 , K. Karakostas 10 , N. Karastathis 10 , M. Karnevskiy 82 , S.N. Karpov 64 , Z.M. Karpova 64 , K. Karthik 109 , V. Kartvelishvili 71 , A.N. Karyukhin 129 , L. Kashif 174 , G. Kasieczka 58b , R.D. Kass 110 , A. Kastanas 14 , Y. Kataoka 156 , A. Katre 49 , J. Katzy 42 , V. Kaushik 7 , K. Kawagoe 69 , T. Kawamoto 156 , G. Kawamura 54 , S. Kazama 156 , V.F. Kazanin 108 , M.Y. Kazarinov 64 , R. Keeler 170 , R. Kehoe 40 , M. Keil 54 , J.S. Keller 42 , J.J. Kempster 76 , H. Keoshkerian 5 , O. Kepka 126 , B.P. Kerˇsevan 74 , S. Kersten 176 , K. Kessoku 156 ,
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### Measurement of the isolated diphoton cross section in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

E.B. Klinkby 35 , T. Klioutchnikova 29 , P.F. Klok 104 , S. Klous 105 , E.-E. Kluge 58a , T. Kluge 73 , P. Kluit 105 , S. Kluth 99 , E. Kneringer 62 , J. Knobloch 29 , E.B.F.G. Knoops 83 , A. Knue 54 , B.R. Ko 44 , T. Kobayashi 155 , M. Kobel 43 , M. Kocian 143 , A. Kocnar 113 , P. Kodys 126 , K. K¨ oneke 29 , A.C. K¨ onig 104 , S. Koenig 81 , L. K¨opke 81 , F. Koetsveld 104 , P. Koevesarki 20 , T. Koffas 29 , E. Koffeman 105 , F. Kohn 54 , Z. Kohout 127 , T. Kohriki 66 , T. Koi 143 , T. Kokott 20 , G.M. Kolachev 107 , H. Kolanoski 15 , V. Kolesnikov 65 , I. Koletsou 89a , J. Koll 88 , D. Kollar 29 , M. Kollefrath 48 , S.D. Kolya 82 , A.A. Komar 94 , J.R. Komaragiri 142 , Y. Komori 155 , T. Kondo 66 , T. Kono 41,o , A.I. Kononov 48 , R. Konoplich 108,p , N. Konstantinidis 77 , A. Kootz 174 , S. Koperny 37 , S.V. Kopikov 128 , K. Korcyl 38 , K. Kordas 154 , V. Koreshev 128 , A. Korn 14 , A. Korol 107 , I. Korolkov 11 , E.V. Korolkova 139 , V.A. Korotkov 128 , O. Kortner 99 , S. Kortner 99 , V.V. Kostyukhin 20 , M.J. Kotam¨ aki 29 , S. Kotov 99 , V.M. Kotov 65 , A. Kotwal 44 , C. Kourkoumelis 8 , V. Kouskoura 154 , A. Koutsman 105 , R. Kowalewski 169 , T.Z. Kowalski 37 , W. Kozanecki 136 , A.S. Kozhin 128 ,
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### Measurement of the $ZZ$ Production Cross Section in $pp$ Collisions at $\sqrt{s}$ = 13 TeV with the ATLAS Detector

MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Den- mark; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Feder- ation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DST /NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, the Canada Council, CANARIE, CRC, Compute Canada, FQRNT, and the Ontario Innovation Trust, Canada; EPLANET, ERC, FP7, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union; Investisse- ments d’Avenir Labex and Idex, ANR, Region Auvergne and Fondation Partager le Savoir, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF; BSF, GIF and Minerva, Israel; BRF, Norway; the Royal Society and Leverhulme Trust, United Kingdom.
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### Measurement of the jet mass in high transverse momentum $Z(\rightarrow b\overline{b})\gamma$ production at $\sqrt{s}= 13$ TeV using the ATLAS detector

The systematic uncertainty due to the dependence of the unfolding on the prior signal distribution, as obtained from MC simulations, is evaluated through a data-driven ‘closure test’. The simulated signal sample is reweighted at particle level such that the distribution of the fully simulated reconstructed jet mass more closely matches the observed data. Pseudo-data from the reweighted signal MC sample are then unfolded using the response matrix from the original unweighted signal MC sample, and the unfolded result is compared with the reweighted particle-level distribution. Differences observed in this comparison are taken as systematic uncertainties in the unfolding, and are referred to as unfolding non-closure uncertainties in the following. The uncertainty due to the dependence on the number of unfolding iteration steps is negligible. The statistical uncertainties in the signal MC sample, used to build the response matrix, and background templates are also considered.
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