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Author Caron, S.; Gomez-Vargas, G.A.; Hendriks, L.; Ruiz de Austri, R.
Title Analyzing gamma rays of the Galactic Center with deep learning Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 05 Issue 5 Pages 058 - 24pp
Keywords gamma ray experiments; dark matter simulations
Abstract We present the application of convolutional neural networks to a particular problem in gamma ray astronomy. Explicitly, we use this method to investigate the origin of an excess emission of GeV gamma rays in the direction of the Galactic Center, reported by several groups by analyzing Fermi-LAT data. Interpretations of this excess include gamma rays created by the annihilation of dark matter particles and gamma rays originating from a collection of unresolved point sources, such as millisecond pulsars. We train and test convolutional neural networks with simulated Fermi-LAT images based on point and diffuse emission models of the Galactic Center tuned to measured gamma ray data. Our new method allows precise measurements of the contribution and properties of an unresolved population of gamma ray point sources in the interstellar diffuse emission model. The current model predicts the fraction of unresolved point sources with an error of up to 10% and this is expected to decrease with future work.
Address [Caron, Sascha; Hendriks, Luc] Radboud Univ Nijmegen, Fac Sci, Inst Math Astrophys & Particle Phys, Mailbox 79,POB 9010, NL-6500 GL Nijmegen, Netherlands, Email: scaron@cern.ch;
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 WOS:000432869300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3582
Permanent link to this record
 
 
Author Olleros, P.; Caballero, L.; Domingo-Pardo, C.; Babiano, V.; Ladarescu, I.; Calvo, D.; Gramage, P.; Nacher, E.; Tain, J.L.; Tolosa, A.
Title On the performance of large monolithic LaCl3(Ce) crystals coupled to pixelated silicon photosensors Type Journal Article
Year 2018 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 13 Issue Pages P03014 - 17pp
Keywords Compton imaging; Detector modelling and simulations I (interaction of radiation with matter interaction of photons with matter interaction of hadrons with matter etc); Gamma detectors (scintillators CZT HPG HgI etc); Instrumentation and methods for time-of-flight (TOF); spectroscopy
Abstract We investigate the performance of large area radiation detectors, with high energy-and spatial-resolution, intended for the development of a Total Energy Detector with gamma-ray imaging capability, so-called i-TED. This new development aims for an enhancement in detection sensitivity in time-of-flight neutron capture measurements, versus the commonly used C6D6 liquid scintillation total-energy detectors. In this work, we study in detail the impact of the readout photosensor on the energy response of large area (50 x 50 mm(2)) monolithic LaCl3(Ce) crystals, in particular when replacing a conventional mono-cathode photomultiplier tube by an 8 x 8 pixelated silicon photomultiplier. Using the largest commercially available monolithic SiPM array (25 cm(2)), with a pixel size of 6 x 6 mm(2), we have measured an average energy resolution of 3.92% FWHM at 662 keV for crystal thick-nesses of 10, 20 and 30 mm. The results are confronted with detailed Monte Carlo (MC) calculations, where optical processes and properties have been included for the reliable tracking of the scintillation photons. After the experimental validation of the MC model, we use our MC code to explore the impact of a smaller photosensor segmentation on the energy resolution. Our optical MC simulations predict only a marginal deterioration of the spectroscopic performance for pixels of 3 x 3 mm(2).
Address [Olleros, P.; Caballero, L.; Domingo-Pardo, C.; Babiano, V.; Ladarescu, I.; Calvo, D.; Gramage, P.; Tain, J. L.; Tolosa, A.] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: Luis.Caballero@ific.uv.es
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:000428146300004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial (down) 3542
Permanent link to this record
 
 
Author ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Higon-Rodriguez, E.; Jimenez Pena, J.; Lacasta, C.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Bosca, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Study of the material of the ATLAS inner detector for Run 2 of the LHC Type Journal Article
Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 12 Issue Pages P12009 - 59pp
Keywords Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter etc); Particle tracking detectors; Performance of High Energy Physics Detectors
Abstract The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity root s = 13 TeV pp collision sample corresponding to around 2.0 nb(-1) collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.
Address [Jackson, P.; Pettersson, N. E.; Whiter, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia
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:000417761100006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3416
Permanent link to this record
 
 
Author NEXT Collaboration (Azevedo, C.D.R. et al); Gomez-Cadenas, J.J.; Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Ferrario, P.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.
Title Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 877 Issue Pages 157-172
Keywords Optical TPCs; Microscopic simulation; Xenon scintillation
Abstract We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.
Address [Azevedo, C. D. R.] Univ Aveiro, I3N, Phys Dept, Aveiro, Portugal, Email: Diego.Gonzalez.Diaz@usc.es
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 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000415128000022 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3371
Permanent link to this record
 
 
Author de Salas, P.F.; Gariazzo, S.; Lesgourgues, J.; Pastor, S.
Title Calculation of the local density of relic neutrinos Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 09 Issue 9 Pages 034 - 24pp
Keywords cosmological neutrinos; dark matter simulations; galaxy clustering; neutrino experiments
Abstract Nonzero neutrino masses are required by the existence of flavour oscillations, with values of the order of at least 50 meV. We consider the gravitational clustering of relic neutrinos within the Milky Way, and used the N – one-body simulation technique to compute their density enhancement factor in the neighbourhood of the Earth with respect to the average cosmic density. Compared to previous similar studies, we pushed the simulation down to smaller neutrino masses, and included an improved treatment of the baryonic and dark matter distributions in the Milky Way. Our results are important for future experiments aiming at detecting the cosmic neutrino background, such as the Princeton Tritium Observatory for Light, Early-universe, Massive-neutrino Yield (PTOLEMY) proposal. We calculate the impact of neutrino clustering in the Milky Way on the expected event rate for a PTOLEMY-like experiment. We find that the effect of clustering remains negligible for the minimal normal hierarchy scenario, while it enhances the event rate by 10 to 20% (resp. a factor 1.7 to 2.5) for the minimal inverted hierarchy scenario (resp. a degenerate scenario with 150 meV masses). Finally we compute the impact on the event rate of a possible fourth sterile neutrino with a mass of 1.3 eV.
Address [de Salas, P. F.; Gariazzo, S.; Pastor, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient UV,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: pabferde@ific.uv.es;
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 WOS:000411617000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3308
Permanent link to this record
 
 
Author BRIKEN Collaboration (Tarifeño-Saldivia, A. et al); Tain, J.L.; Domingo-Pardo, C.; Agramunt, J.; Algora, A.; Morales, A.I.; Rubio, B.; Tolosa, A.
Title Conceptual design of a hybrid neutron-gamma detector for study of beta-delayed neutrons at the RIB facility of RIKEN Type Journal Article
Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 12 Issue Pages P04006 - 22pp
Keywords Detector modelling and simulations I (interaction of radiation with matter, interaction; of photons with matter, interaction of hadrons with matter, etc); Instrumentation for radioactive beams (fragmentation devices; fragment and isotope, separators incl. ISOL; isobar separators; ion and atom traps; weak-beam diagnostics; radioactive-beam ion sources); Neutron detectors (cold, thermal, fast neutrons)
Abstract BRIKEN is a complex detection system to be installed at the RIB-facility of the RIKEN Nishina Center. It is aimed at the detection of heavy-ion implants, β-particles, γ-rays and β-delayed neutrons. The whole detection setup involves the Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors and a large set of 166 counters of 3He embedded in a high-density polyethylene matrix. This article reports on a novel methodology developed for the conceptual design and optimisation of the 3He-tubes array, aiming at the best possible performance in terms of neutron detection. The algorithm is based on a geometric representation of two selected parameters of merit, namely, average neutron detection efficiency and efficiency flatness, as a function of a reduced number of geometric variables. The response of the detection system itself, for each configuration, is obtained from a systematic MC-simulation implemented realistically in Geant4. This approach has been found to be particularly useful. On the one hand, due to the different types and large number of 3He-tubes involved and, on the other hand, due to the additional constraints introduced by the ancillary detectors for charged particles and gamma-rays. Empowered by the robustness of the algorithm, we have been able to design a versatile detection system, which can be easily re-arranged into a compact mode in order to maximize the neutron detection performance, at the cost of the gamma-ray sensitivity. In summary, we have designed a system which shows, for neutron energies up to 1(5) MeV, a rather flat and high average efficiency of 68.6%(64%) and 75.7%(71%) for the hybrid and compact modes, respectively. The performance of the BRIKEN system has been also quantified realistically by means of MC-simulations made with different neutron energy distributions.
Address [Tarifeno-Saldivia, A.] UPC, Barcelona, Spain, Email: ariel.esteban.tarifeno@upc.edu
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:000405067800006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3209
Permanent link to this record
 
 
Author Guadilla, V. et al; Algora, A.; Tain, J.L.; Agramunt, J.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S.E.A.; Rubio, B.; Valencia, E.
Title Characterization of a cylindrical plastic beta-detector with Monte Carlo simulations of optical photons Type Journal Article
Year 2017 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 854 Issue Pages 134-138
Keywords Plastic scintillators; Monte Carlo simulations; Total absorption spectroscopy; Optical photons
Abstract In this work we report on the Monte Carlo study performed to understand and reproduce experimental measurements of a new plastic beta-detector with cylindrical geometry. Since energy deposition simulations differ from the experimental measurements for such a geometry, we show how the simulation of production and transport of optical photons does allow one to obtain the shapes of the experimental spectra. Moreover, taking into account the computational effort associated with this kind of simulation, we develop a method to convert the simulations of energy deposited into light collected, depending only on the interaction point in the detector. This method represents a useful solution when extensive simulations have to be done, as in the case of the calculation of the response function of the spectrometer in a total absorption gamma-ray spectroscopy analysis.
Address [Guadilla, V.; Algora, A.; Tain, J. L.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S. E. A.; Rubio, B.; Valencia, E.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: victor.guadilla@ific.uv.es
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 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000398869100018 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3052
Permanent link to this record
 
 
Author ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; 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.; Jimenez Pena, J.; King, M.; Lacasta, C.; Lacuesta, V.R.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title A measurement of material in the ATLAS tracker using secondary hadronic interactions in 7 TeV p p collisions Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages P11020 - 41pp
Keywords Detector modelling and simulations I (interaction of radiation with matter, interaction; of photons with matter, interaction of hadrons with matter, etc); Performance of High Energy Physics Detectors
Abstract Knowledge of the material in the ATLAS inner tracking detector is crucial in under-standing the reconstruction of charged-particle tracks, the performance of algorithms that identify jets containing b-hadrons and is also essential to reduce background in searches for exotic particles that can decay within the inner detector volume. Interactions of primary hadrons produced in pp collisions with the material in the inner detector are used to map the location and amount of this material. The hadronic interactions of primary particles may result in secondary vertices, which in this analysis are reconstructed by an inclusive vertex-finding algorithm. Data were collected using minimum-bias triggers by the ATLAS detector operating at the LHC during 2010 at centre-of-mass energy root s = 7 TeV, and correspond to an integrated luminosity of 19 nb(-1). Kinematic properties of these secondary vertices are used to study the validity of the modelling of hadronic interactions in simulation. Secondary-vertex yields are compared between data and simulation over a volume of about 0.7m(3) around the interaction point, and agreement is found within overall uncertainties.
Address [Jackson, P.; Lee, L.; Petridis, A.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia
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:000395673100020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 3042
Permanent link to this record
 
 
Author XENON Collaboration (Aprile, E. et al); Orrigo, S.E.A.
Title Physics reach of the XENON1T dark matter experiment Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 027 - 37pp
Keywords dark matter simulations; dark matter experiments
Abstract The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in 1 tonne fiducial volume and (1, 12) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is (1.80+/-0.15) . 10(-4) (kg.day.keV)(-1), mainly due to the decay of Rn-222 daughters inside the xenon target. The nuclear recoil background in the corresponding nuclear recoil equivalent energy region (4, 50) keV, is composed of (0.6 +/- 0.1) (t.y)(-1) from radiogenic neutrons, (1.8+/-0.3) . 10(-2) (t.y)(-1) from coherent scattering of neutrinos, and less than 0.01 (t.y)(-1) from muon-induced neutrons. The sensitivity of XENON1T is calculated with the Pro file Likelihood Ratio method, after converting the deposited energy of electronic and nuclear recoils into the scintillation and ionization signals seen in the detector. We take into account the systematic uncertainties on the photon and electron emission model, and on the estimation of the backgrounds, treated as nuisance parameters. The main contribution comes from the relative scintillation efficiency L-eff, which affects both the signal from WIMPs and the nuclear recoil backgrounds. After a 2 y measurement in 1 tonne fiducial volume, the sensitivity reaches a minimum cross section of 1.6 . 10(-47) cm(2) at m(chi) = 50 GeV/c(2).
Address [Aprile, E.; Anthony, M.; Contreras, H.; de Perio, P.; Goetzke, L. W.; Greene, Z.; Fernandez, A. J. Melgarejo; Messina, M.; Plante, G.; Rizzo, A.; Weber, M.; Zhang, Y.] Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA, Email: cyril.grignon@uni-mainz.de;
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 WOS:000393286400005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 2950
Permanent link to this record
 
 
Author Athenodorou, A.; Binosi, D.; Boucaud, P.; De Soto, F.; Papavassiliou, J.; Rodriguez-Quintero, J.; Zafeiropoulos, S.
Title On the zero crossing of the three-gluon vertex Type Journal Article
Year 2016 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 761 Issue Pages 444-449
Keywords Lattice simulations; Three-gluon vertex; Zero crossing; Schwinger-Dyson equations
Abstract We report on new results on the infrared behavior of the three-gluon vertex in quenched Quantum Chromodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as 'zero crossing', the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev-Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger-Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing the vanishing of the effective interaction at the exact location of the zero crossing.
Address [Athenodorou, A.] Univ Cyprus, Dept Phys, POB 20537, CY-1678 Nicosia, Cyprus, Email: binosi@ectstar.eu
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000384469900063 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (down) 2939
Permanent link to this record