|   | 
Details
   web
Records
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title The rapid atmospheric monitoring system of the Pierre Auger Observatory Type Journal Article
Year 2012 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 7 Issue Pages P09001 - 41pp
Keywords Large detector systems for particle and astroparticle physics; Real-time monitoring; Control and monitor systems online
Abstract The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or “rapid”) monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Diogo, F.; Espadanal, J.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] Univ Tecn Lisboa, LIP, P-1100 Lisbon, Portugal
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000309547100003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1233
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Measurement of the Proton-Air Cross Section at root s=57 TeV with the Pierre Auger Observatory Type Journal Article
Year 2012 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 109 Issue 6 Pages 062002 - 9pp
Keywords
Abstract We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505 +/- 22(stat)(-36)(+28)(syst)] mb is found.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Espadanal, J.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] Univ Tecn Lisboa, LIP, P-1100 Lisbon, Portugal
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000307381900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1137
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Search for signatures of magnetically-induced alignment in the arrival directions measured by the Pierre Auger Observatory Type Journal Article
Year 2012 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 35 Issue 6 Pages 354-361
Keywords Ultra-high energy cosmic rays; Pierre auger observatory; Arrival directions
Abstract We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or 'multiplets') which exhibit a correlation between arrival direction and the inverse of the energy. These signatures are expected from sets of events coming from the same source after having been deflected by intervening coherent magnetic fields. The observation of several events from the same source would open the possibility to accurately reconstruct the position of the source and also measure the integral of the component of the magnetic field orthogonal to the trajectory of the cosmic rays. We describe the largest multiplets found and compute the probability that they appeared by chance from an isotropic distribution. We find no statistically significant evidence for the presence of multiplets arising from magnetic deflections in the present data.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Espadanal, J.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] Univ Tecn Lisbon, LIP, P-1100 Lisbon, Portugal, Email: auger_spokepersons@fnal.gov
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-6505 ISBN Medium
Area Expedition Conference
Notes WOS:000300760800008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 935
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays Type Journal Article
Year 2011 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 6 Issue Pages P01003 - 16pp
Keywords Cherenkov detectors; Large detector systems for particle and astroparticle physics; Particle detectors
Abstract Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes ISI:000291345600003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 646
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Search for first harmonic modulation in the right ascension distribution of cosmic rays detected at the Pierre Auger Observatory Type Journal Article
Year 2011 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 34 Issue 8 Pages 627-639
Keywords Ultra-high energy cosmic rays; Large scale anisotropies; Pierre Auger Observatory
Abstract We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 x 10(17) eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-6505 ISBN Medium
Area Expedition Conference
Notes ISI:000288930200007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 593
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory Type Journal Article
Year 2011 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 06 Issue 6 Pages 022 - 17pp
Keywords ultra high energy cosmic rays; cosmic ray experiments
Abstract The Pierre Auger Collaboration has reported. evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > E-th = 5.5 x 10(19) eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > E-th are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above E-th/Z (for illustrative values of Z = 6, 13, 26). If the anisotropies above E-th are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal, Email: auger_spokepersons@fnal.gov
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes ISI:000292332400022 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 676
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray showers detected by the Pierre Auger Observatory Type Journal Article
Year 2011 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 35 Issue 5 Pages 266-276
Keywords Ultra-High Energy Cosmic Rays; Pierre Auger Observatory; Extensive Air Showers; Trigger performance; Surface detector; Hybrid detector
Abstract In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10(17) and 10(19) eV and zenith angles up to 65 degrees. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data
Address (up) [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal, Email: auger_spokespersons@fnal.gov
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-6505 ISBN Medium
Area Expedition Conference
Notes WOS:000297434500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 837
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Moles-Valls, R.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Vos, M.
Title Measurement of flow harmonics with multi-particle cumulants in Pb plus Pb collisions at root(NN)-N-S=2.76 TeV with the ATLAS detector Type Journal Article
Year 2014 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 74 Issue 11 Pages 3157 - 28pp
Keywords
Abstract ATLAS measurements of the azimuthal anisotropy in lead-lead collisions at root(NN)-N-S = 2.76 TeV are shown using a dataset of approximately 7 μb(-1) collected at the LHC in 2010. The measurements are performed for charged particles with transverse momenta 0.5 < p(T) < 20 GeV and in the pseudorapidity range vertical bar eta vertical bar < 2.5. The anisotropy is characterized by the Fourier coefficients, vn, of the charged-particle azimuthal angle distribution for n = 2-4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the v(n) coefficients are presented. The elliptic flow, v(2), is obtained from the two-, four-, six-and eight-particle cumulants while higher-order coefficients, v(3) and v(4), are determined with two-and four-particle cumulants. Flow harmonics v(n) measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to v(n) measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multiparticle cumulants are shown as a function of transverse momentum and the collision centrality. Models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.
Address (up) [Abreu, R.; Aleksa, M.; Andari, N.; Anders, G.; Anghinolfi, F.; Armbruster, A. J.; Arnaez, O.; Avolio, G.; Baak, M. A.; Backes, M.; Backhaus, M.; Battistin, M.; Beltramello, O.; Bianco, M.; Bogaerts, J. A.; Boyd, J.; Burckhart, H.; Campana, S.; Garrido, M. D. M. Capeans; Carli, T.; Catinaccio, A.; Cattai, A.; Cerv, M.; Chromek-Burckhart, D.; Dell'Acqua, A.; Di Girolamo, A.; Di Girolamo, B.; Dittus, F.; Dobos, D.; Dudarev, A.; Duhrssen, M.; Ellis, N.; Elsing, M.; Farthouat, P.; Fassnacht, P.; Feigl, S.; Perez, S. Fernandez; Franchino, S.; Francis, D.; Froidevaux, D.; Garonne, V.; Gianotti, F.; Gillberg, D.; Glatzer, J.; Godlewski, J.; Goossens, L.; Gorini, B.; Gray, H. M.; Hauschild, M.; Hawkings, R. J.; Heller, M.; Helsens, C.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Hubacek, Z.; Huhtinen, M.; Jaekel, M. R.; Jakobsen, S.; Jansen, H.; Jenni, P.; Jungst, R. M.; Kaneda, M.; Klioutchnikova, T.; Krasznahorkay, A.; Lantzsch, K.; Lassnig, M.; Miotto, G. Lehmann; Lenzi, B.; Lichard, P.; Macina, D.; Malyukov, S.; Mandelli, B.; Mapelli, L.; Martin, B.; Marzin, A.; Messina, A.; Meyer, J.; Milic, A.; Mornacchi, G.; Nairz, A. M.; Nakahama, Y.; Negri, G.; Nessi, M.; Nicquevert, B.; Nordberg, M.; Palestini, S.; Pauly, T.; Pernegger, H.; Peters, K.; Petersen, B. A.; Pommes, K.; Poppleton, A.; Poulard, G.; Prasad, S.; Rammensee, M.; Raymond, M.; Rembser, C.; Rodrigues, L.; Roe, S.; Ruiz-Martinez, A.; Salzburger, A.; Savu, D. O.; Schaefer, D.; Schlenker, S.; Schmieden, K.; Serfon, C.; Sfyrla, A.; Solans, C. A.; Spigo, G.; Stelzer, H. J.; Teischinger, F. A.; Ten Kate, H.; Tremblet, L.; Tricoli, A.; Tsarouchas, C.; Unal, G.; van der Ster, D.; van Eldik, N.; van Woerden, M. C.; Vandelli, W.; Vigne, R.; Voss, R.; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Werner, P.; Wilkens, H. G.; Wotschack, J.; Young, C. J. S.; Zwalinski, L.; ATLAS Collaboration] CERN, CH-1211 Geneva 23, Switzerland
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000347177000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2103
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Moles-Valls, R.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Vos, M.
Title Measurements of the Higgs boson production and decay rates and coupling strengths using pp collision data at root s=7 and 8 TeV in the ATLAS experiment Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 1 Pages 6 - 51pp
Keywords
Abstract Combined analyses of the Higgs boson production and decay rates as well as its coupling strengths to vector bosons and fermions are presented. The combinations include the results of the analyses of the H -> gamma gamma, ZZ*, WW*, Z gamma, b (b) over bar, tau tau and μμdecay modes, and the constraints on the associated production with a pair of top quarks and on the off-shell coupling strengths of the Higgs boson. The results are based on the LHC proton-proton collision datasets, with integrated luminosities of up to 4.7 fb(-1) at root s = 7 TeV and 20.3 fb(-1) at root s = 8 TeV, recorded by the ATLAS detector in 2011 and 2012. Combining all production modes and decay channels, the measured signal yield, normalised to the Standard Model expectation, is 1.18(-0.14)(+0.15). The observed Higgs boson production and decay rates are interpreted in a leading-order coupling framework, exploring a wide range of benchmark coupling models both with and without assumptions on the Higgs boson width and on the Standard Model particle content in loop processes. The data are found to be compatible with the Standard Model expectations for a Higgs boson at a mass of 125.36 GeV for all models considered.
Address (up) [Abreu, R.; Aleksa, M.; Gonzalez, B. Alvarez; Andari, N.; Anders, G.; Anghinolfi, F.; Armbruster, A. J.; Arnaez, O.; Avolio, G.; Baak, M. A.; Backes, M.; Backhaus, M.; Barak, L.; Beltramello, O.; Bianco, M.; Bogaerts, J. A.; Boveia, A.; Boyd, J.; Burckhart, H.; Campana, S.; Garrido, M. D. M. Capeans; Carli, T.; Catinaccio, A.; Cattai, A.; Cerv, M.; Chromek-Burckhart, D.; Conti, G.; Dell'Acqua, A.; Deviveiros, P. O.; Di Girolamo, A.; Di Girolamo, B.; Dittus, F.; Dobos, D.; Dudarev, A.; Duehrssen, M.; Eifert, T.; Ellis, N.; Elsing, M.; Farthouat, P.; Fassnacht, P.; Feigl, S.; Perez, S. Fernandez; Francis, D.; Froidevaux, D.; Gillberg, D.; Glatzer, J.; Goossens, L.; Gorini, B.; Gray, H. M.; Hawkings, R. J.; Helsens, C.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Hubacek, Z.; Huhtinen, M.; Iengo, P.; Jaekel, M. R.; Jakobsen, S.; Kaneda, M.; Klioutchnikova, T.; Krasznahorkay, A.; Lantzsch, K.; Lapoire, C.; Lassnig, M.; Miotto, G. Lehmann; Lenzi, B.; Lichard, P.; Macina, D.; Malyukov, S.; Mandelli, B.; Mapelli, L.; Marzin, A.; Milic, A.; Mornacchi, G.; Nairz, A. M.; Nakahama, Y.; Nessi, M.; Nicquevert, B.; Nordberg, M.; Oide, H.; Palestini, S.; Pauly, T.; Pernegger, H.; Peters, K.; Petersen, B. A.; Pommes, K.; Poppleton, A.; Poulard, G.; Poveda, J.; Prasad, S.; Rammensee, M.; Raymond, M.; Rembser, C.; Roe, S.; Ruiz-Martinez, A.; Salzburger, A.; Schaefer, D.; Schlenker, S.; Schmieden, K.; Serfon, C.; Sfyrla, A.; Solans, C. A.; Spigo, G.; Stelzer, H. J.; Teischinger, F. A.; Ten Kate, H.; Tremblet, L.; Tricoli, A.; Tsarouchas, C.; Unal, G.; van Woerden, M. C.; Vandelli, W.; Vigne, R.; Voss, R.; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Werner, P.; Wilkens, H. G.; Wotschack, J.; Young, C. J. S.; Zwalinski, L.; ATLAS Collaboration] CERN, CH-1211 Geneva 23, Switzerland
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000370645100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2566
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Cardillo, F.; Castillo, F.L.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Ferrer, A.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Mitsou, V.A.; Moreno Llacer, M.; Poveda, J.; Prades Ibañez, A.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Santra, A.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb(-1) of Pb+Pb data with the ATLAS detector Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 243 - 45pp
Keywords Hadron-Hadron scattering (experiments)
Abstract This paper describes a measurement of light-by-light scattering based on Pb+Pb collision data recorded by the ATLAS experiment during Run 2 of the LHC. The study uses 2.2 nb(-1) of integrated luminosity collected in 2015 and 2018 at root sNN = 5.02TeV. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy E-T(gamma) > 2.5 GeV, pseudorapidity vertical bar eta(gamma)vertical bar < 2.37, diphoton invariant mass m(gamma gamma) > 5 GeV, and with small diphoton transverse momentum and diphoton acoplanarity. The integrated and differential fiducial cross sections are measured and compared with theoretical predictions. The diphoton invariant mass distribution is used to set limits on the production of axion-like particles. This result provides the most stringent limits to date on axion-like particle production for masses in the range 6-100 GeV. Cross sections above 2 to 70 nb are excluded at the 95% CL in that mass interval.
Address (up) [Abud, A. Abed; Ahmad, A.; Alderweireldt, S.; Aleksa, M.; Allaire, C.; Aranzabal, N.; Armbruster, A. J.; Avolio, G.; Barisits, M-S; Bielski, R.; Bisanz, T.; Boyd, J.; Brenner, L.; Butti, P.; Buttinger, W.; Calace, N.; Camarda, S.; Camincher, C.; Campana, S.; Garrido, M. D. M. Capeans; Carli, T.; Catinaccio, A.; Cattai, A.; Coimbra, A. E. C.; Czodrowski, P.; Dachs, F.; Dao, V; Dell'Acqua, A.; Deviveiros, P. O.; Di Girolamo, A.; Dittus, F.; Ducu, O. A.; Dudarev, A.; Duhrssen, M.; Dyndal, M.; Ellis, N.; Elsing, M.; Falke, S.; Farthouat, P.; Fassnacht, P.; Francis, D.; Froidevaux, D.; Gabrielli, A.; Goossens, L.; Gorini, B.; Guindon, S.; Hawkings, R. J.; Heinrich, L.; Helsens, C.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Huhtinen, M.; Iengo, P.; Jenni, P.; Jovicevic, J.; Kiehn, M.; Klimek, P.; Klioutchnikova, T.; Kohler, N. M.; Krasznahorkay, A.; Kuehn, S.; Kuwertz, E. S.; Lassnig, M.; Miotto, G. Lehmann; Longo, L.; Marzin, A.; Meehan, S.; Meng, L.; Berlingen, J. Montejo; Morley, A. K.; Mornacchi, G.; Moschovakos, P.; Nairz, A. M.; Nessi, M.; Nordberg, M.; Palestini, S.; Pauly, T.; Pernegger, H.; Perrella, S.; Petersen, B. A.; Pontecorvo, L.; Astigarraga, M. E. Pozo; Queitsch-Maitland, M.; Raymond, M.; Rembser, C.; Rizzi, C.; Roe, S.; Rummler, A.; Saimpert, M.; Salzburger, A.; Samarati, J.; Pineda, A. Sanchez; Schlenker, S.; Schovancova, J.; Sharma, A.; Sidiropoulou, O.; Oliveira, M. V. Silva; Sanchez, C. A. Solans; Spigo, G.; Stewart, G. A.; Stockton, M. C.; Ten Kate, H.; Unal, G.; Vafeiadis, T.; Vallier, A.; Vandelli, W.; Schroeder, T. Vazquez; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Wilkens, H. G.; Young, C. J. S.; Zambito, S.; Zanzi, D.; Zwalinski, L.; ATLAS Collaboration] CERN, CH-1211 Geneva 23, Switzerland
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000634886800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4768
Permanent link to this record