Journal Article

 2017-12-1215:51 [PUBDB-2017-13366] Journal Article Behr, J. K. Searches for Exotic Physics in ATLAS using Substructure Techniques Workshop on Discovery Physics at the LHC, Kruger2016, Meeting locationMpumulanga, South Africa, 5 Dec 2016 - 9 Dec 2016   The significant increase of the centre-of-mass energy of the Large Hadron Collider (LHC) from 8 to 13 TeV has allowed the LHC experiments to explore previously inaccessible kinematic regimes in their search for phenomena beyond the Standard Model. The sensitivity of these searches depends crucially on the efficient reconstruction and identification of hadronic decays of highly energetic (boosted) objects, the decay products of which are typically collimated into a single large jet with a characteristic substructure [...] OpenAccess: PDF PDF (PDFA); 2017-12-1215:37 [PUBDB-2017-13364] Journal Article/Contribution to a conference proceedings For the HERMES Collaboration Ratios of helicity amplitudes for exclusive $\rho^0$ electroproduction on transversely polarized proton XXIII International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and Quantum Chromodynamics", Baldin ISHEPP XXIII, Meeting locationDubna, Russia, 19 Sep 2016 - 24 Sep 2016   Exclusive $\rho^0$-meson electroproduction is studied by the HERMES experiment, using the 27.6 GeV longitudinally polarized electron/positron beam of HERA and a transversely polarized hydrogen target, in the kinematic region 1.0 GeV$^2$ < Q$^2$ < 7.0 GeV$^2$, 3.0 GeV < W < 6.3 GeV, and −t′ < 0.4 GeV$^2$. Using an unbinned maximum-likelihoodmethod, 25 parameters are extracted. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2017-12-1214:52 [PUBDB-2017-13357] Preprint/Report et al Measurement of the cross-section for electroweak production of dijets in association with a Z boson in pp collisions at s = 13   TeV with the ATLAS detector [CERN-EP-2017-115] Physics letters / B 775, 206 - 228 (2017) [10.1016/j.physletb.2017.10.040]   The cross-section for the production of two jets in association with a leptonically decaying Z boson ($Zjj$) is measured in proton--proton collisions at a centre-of-mass energy of 13 TeV, using data recorded with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 3.2 fb$^{-1}$. The electroweak $Zjj$ cross-section is extracted in a fiducial region chosen to enhance the electroweak contribution relative to the dominant Drell--Yan $Zjj$ process, which is constrained using a data-driven approach. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:53 [PUBDB-2017-13343] Preprint/Report et al Jet energy scale measurements and their systematic uncertainties in proton-proton collisions at s = 13     TeV with the ATLAS detector [CERN-EP-2017-038] Physical review / D 96(7), 072002 (2017) [10.1103/PhysRevD.96.072002]   Jet energy scale measurements and their systematic uncertainties are reported for jets measured with the ATLAS detector using proton-proton collision data with a center-of-mass energy of $\sqrt{s} = 13$ TeV, corresponding to an integrated luminosity of 3.2 fb$^{-1}$ collected during 2015 at the LHC. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells, using the anti-$k_{t}$ algorithm with radius parameter $R = 0.4$. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:50 [PUBDB-2017-13341] Report/Journal Article et al Jet reconstruction and performance using particle flow with the ATLAS Detector [CERN-EP-2017-024]   This paper describes the implementation and performance of a particle flow algorithm applied to 20.2 fb$^{-1}$ of ATLAS data from 8 TeV proton-proton collisions in Run 1 of the LHC. The algorithm removes calorimeter energy deposits due to charged hadrons from consideration during jet reconstruction, instead using measurements of their momenta from the inner tracker. [...] Restricted: PDF; 2017-12-1213:42 [PUBDB-2017-13338] Preprint/Report et al Search for dark matter at $$\sqrt{s}=13~\mathrm{TeV}$$ s = 13 TeV in final states containing an energetic photon and large missing transverse momentum with the ATLAS detector [CERN-EP-2017-044]   Results of a search for physics beyond the Standard Model in events containing an energetic photon and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. As the number of events observed in data, corresponding to an integrated luminosity of 36.1 $\textrm fb^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV, is in agreement with the Standard Model expectations, exclusion limits in models where dark-matter candidates are pair-produced are determined. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:40 [PUBDB-2017-13337] Preprint/Report et al Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2 [CERN-EP-2017-045]   With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:35 [PUBDB-2017-13335] Preprint/Report et al Search for new phenomena in a lepton plus high jet multiplicity final state with the ATLAS experiment using s = 13 $$\sqrt{s}=13$$ TeV proton-proton collision data [CERN-EP-2017-053] Journal of high energy physics 2017(9), 88 (2017) [10.1007/JHEP09(2017)088]   A search for new phenomena in final states characterized by high jet multiplicity, an isolated lepton (electron or muon) and either zero or at least three $b$-tagged jets is presented. The search uses 36.1 fb$^{-1}$ of $\sqrt{s}$ = 13 TeV proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider in 2015 and 2016. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:30 [PUBDB-2017-13334] Preprint/Report et al Studies of Zγ production in association with a high-mass dijet system in pp collisions at s = 8 $$\sqrt{s}=8$$ TeV with the ATLAS detector [CERN-EP-2017-046] Journal of high energy physics 2017(7), 107 (2017) [10.1007/JHEP07(2017)107]   The production of a $Z$ boson and a photon in association with a high-mass dijet system is studied using 20.2fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV recorded with the ATLAS detector in 2012 at the Large Hadron Collider. Final states with a photon and a Z boson decaying into a pair of either electrons, muons, or neutrinos are analysed. [...] Restricted: PDF PDF (PDFA); 2017-12-1213:25 [PUBDB-2017-13332] Preprint/Report et al Measurement of b-hadron pair production with the ATLAS detector in proton-proton collisions at s = 8 $$\sqrt{s}=8$$ TeV [CERN-EP-2017-057] Journal of high energy physics 2017(11), 62 (2017) [10.1007/JHEP11(2017)062]   A measurement of $b$-hadron pair production is presented, based on a data set corresponding to an integrated luminosity of 11.4 fb$^{-1}$ of proton--proton collisions recorded at $\sqrt{s}=8$ TeV with the ATLAS detector at the LHC. Events are selected in which a $b$-hadron is reconstructed in a decay channel containing $J/\psi \rightarrow \mu\mu$, and a second $b$-hadron is reconstructed in a decay channel containing a muon. [...] Restricted: PDF PDF (PDFA);