289 research outputs found
Social Inclusion Policies in Higher Education: Evidence from the EU:Overview of major widening participation policies applied in the EU 28
Characterization of microbulk detectors in argon- and neon-based mixtures
A recent Micromegas manufacturing technique, so called Microbulk, has been
developed, improving the uniformity and stability of this kind of detectors.
Excellent energy resolutions have been obtained, reaching values as low as 11%
FWHM at 5.9 keV in Ar+5%iC4H10. This detector has other advantages like its
flexible structure, low material budget and high radio-purity. Two microbulk
detectors with gaps of 50 and 25 um have been characterized in argon- and
neon-based mixtures with ethane, isobutane and cyclohexane. The results will be
presented and discussed. The gain curves have been fitted to the Rose-Korff
gain model and dependences of the electron mean free path and the threshold
energy for ionization have been obtained. The possible relation between these
two parameters and the energy resolution will be also discussed.Comment: Submitted to the Journal of Instrumentatio
Search for neutrino counterparts to the gravitational wave sources from LIGO/Virgo O3 run with the ANTARES detector
Since 2015 the LIGO and Virgo interferometers have detected gravitational waves from almost one hundred coalescences of compact objects (black holes and neutron stars). This article presents the results of a search performed with data from the ANTARES telescope to identify neutrino counterparts to the gravitational wave sources detected during the third LIGO/Virgo observing run and reported in the catalogues GWTC-2, GWTC-2.1, and GWTC-3. This search is sensitive to all-sky neutrinos of all flavours and of energies > 100 GeV, thanks to the inclusion of both track-like events (mainly induced by ¿µ chargedcurrent interactions) and shower-like events (induced by other interaction types). Neutrinos are selected if they are detected within ±500 s from the GW merger and with a reconstructed direction compatible with its sky localisation. No significant excess is found for any of the 80 analysed GW events, and upper limits on the neutrino emission are derived. Using the information from the GW catalogues and assuming isotropic emission, upper limits on the total energy Etot,¿ emitted as neutrinos of all flavours and on the ratio f¿ = Etot,¿/EGW between neutrino and GW emissions are also computed. Finally, a stacked analysis of all the 72 binary black hole mergers (respectively the 7 neutron star-black hole merger candidates) has been performed to constrain the typical neutrino emission within this population, leading to the limits: Etot,¿ < 4.0 × 1053 erg and f¿ < 0.15 (respectively, Etot,¿ < 3.2 × 1053 erg and f¿ < 0.88) for E-2 spectrum and isotropic emission. Other assumptions including softer spectra and non-isotropic scenarios have also been testedPeer ReviewedA. Albert, S. Alves, M. André, M. Ardid, S. Ardid, J.-J. Aubert, J. Aublin, B. Baret, S. Basa, Y. Becherini, B. Belhorma, M. Bendahman, F. Benfenati, V. Bertin, S. Biagi, M. Bissinger, J. Boumaaza, M. Bouta, M.C. Bouwhuis, H. Brânzaş, R. Bruijn, J. Brunner, J. Busto, B. Caiffi, D. Calvo, S. Campion, A. Capone, L. Caramete, F. Carenini, J. Carr, V. Carretero, S. Celli, L. Cerisy, M. Chabab, T.N. Chau, R. Cherkaoui El Moursli, T. Chiarusi, M. Circella, J.A.B. Coelho, A. Coleiro, R. Coniglione, P. Coyle, A. Creusot, A.S.M. Cruz, A.F. Díaz, B. De Martino, C. Distefano, I. Di Palma, A. Domi, C. Donzaud, D. Dornic, D. Drouhin, T. Eberl, T. van Eeden, D. van Eijk, S. El Hedri, N. El Khayati, A. Enzenhöfer, P. Fermani, G. Ferrara, F. Filippini, L. Fusco, S. Gagliardini, J. García, C. Gatius Oliver, P. Gay, N. Geißelbrecht, H. Glotin, R. Gozzini, R. Gracia Ruiz, K. Graf, C. Guidi, L. Haegel, S. Hallmann, H. van Haren, A.J. Heijboer, Y. Hello, J.J. Hernández-Rey, J. Hößl, J. Hofestädt, F. Huang, G. Illuminati, C.W. James, B. Jisse-Jung, M. de Jong, P. de Jong, M. Kadler, O. Kalekin, U. Katz, A. Kouchner, I. Kreykenbohm, V. Kulikovskiy, R. Lahmann, M. Lamoureux, A. Lazo, D. Lefèvre, E. Leonora, G. Levi, S. Le Stum, D. Lopez-Coto, S. Loucatos, L. Maderer, J. Manczak, M. Marcelin, A. Margiotta, A. Marinelli, J.A. Martínez-Mora, P. Migliozzi, A. Moussa, R. Muller, L. Nauta, S. Navas, E. Nezri, B. Ó Fearraigh, A. Păun, G.E. Păvălaş, M. Perrin-Terrin, V. Pestel, P. Piattelli, C. Poirè, V. Popa, T. Pradier, N. Randazzo, D. Real, S. Reck, G. Riccobene, A. Romanov, A. Sánchez-Losa, A. Saina, F. Salesa Greus, D.F.E. Samtleben, M. Sanguineti, P. Sapienza, J. Schnabel, J. Schumann, F. Schüssler, J. Seneca, M. Spurio, Th. Stolarczyk, M. Taiuti, Y. Tayalati, S.J. Tingay, B. Vallage, G. Vannoye, V. Van Elewyck, S. Viola, D. Vivolo, J. Wilms, S. Zavatarelli, A. Zegarelli, J.D. Zornoza, J. ZúñigaPostprint (published version
ANTARES Search for Point Sources of Neutrinos Using Astrophysical Catalogs: A Likelihood Analysis
[EN] A search for astrophysical pointlike neutrino sources using the data collected by the ANTARES detector between 2007 January 29 and 2017 December 31 is presented. A likelihood method is used to assess the signicance of an excess of muon neutrinos inducing track-like events in correlation with the location of a list of possible sources. Different sets of objects are tested in the analysis: (a) a subsample of the Fermi 3LAC catalog of blazars, (b) a jet- obscured population of active galactic nuclei, (c) a sample of hard X-ray selected radio galaxies, (d) a star-forming galaxy catalog, and (e) a public sample of 56 very-high-energy track events from the IceCube experiment. None of the tested sources shows a signi¿cant association with the sample of neutrinos detected by ANTARES. The smallest p-value is obtained for the catalog of radio galaxies with an equal-weights hypothesis, with a pre-trial p- value equivalent to a 2.8sigma excess, which is equivalent to 1.6sigma post-trial. In addition, the results of a dedicated analysis for the blazar MG3 J225517+2409 are also reported: this source is found to be the most signi¿cant within the Fermi 3LAC sample, with five ANTARES events located less than one degree from the source.
This blazar showed evidence of ¿aring activity in Fermi data, in spacetime coincidence with a
high-energy track detected by IceCube. An a posteriori signicance of 2.6sigma for the combination of
ANTARES and IceCube data is reported.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (ref. SOMM17/6104/UGR and A-FQM-053UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.; Aublin, J.... (2021). ANTARES Search for Point Sources of Neutrinos Using Astrophysical Catalogs: A Likelihood Analysis. The Astrophysical Journal. 911(1):1-11. https://doi.org/10.3847/1538-4357/abe53c111911
Search for Neutrinos from the Tidal Disruption Events AT2019dsg and AT2019fdr with the ANTARES Telescope
[EN] On 2019 October 1, the IceCube Collaboration detected a muon track neutrino with a high probability of being of astrophysical origin, IC191001A. After a few hours, the tidal disruption event (TDE) AT2019dsg, observed by the Zwicky Transient Facility (ZTF), was indicated as the most likely counterpart of the IceCube track. More recently, the follow-up campaign of the IceCube alerts by ZTF suggested a second TDE, AT2019fdr, as a promising counterpart of another IceCube muon track candidate, IC200530A, detected on 2020 May 30. Here, these
intriguing associations are followed-up by searching for neutrinos in the ANTARES detector from the directions of AT2019dsg and AT2019fdr using a time-integrated approach. As no significant evidence for space clustering is found in the ANTARES data, upper limits on the one-flavor neutrino flux and fluence are set.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MCI) and Agencia Estatal de Investigacion: Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCI/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider, Junta de Andalucia (ref. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034) programs, Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Alves, S.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.... (2021). Search for Neutrinos from the Tidal Disruption Events AT2019dsg and AT2019fdr with the ANTARES Telescope. The Astrophysical Journal. 920(1):1-6. https://doi.org/10.3847/1538-4357/ac16d616920
ANTARES upper limits on the multi-TeV neutrino emission from the GRBs detected by IACTs
[EN] The first gamma-ray burst detections by Imaging Atmospheric Cherenkov Telescopes
have been recently announced: GRB 190114C, detected by MAGIC, GRB 180720B
and GRB 190829A, observed by H.E.S.S. A dedicated search for neutrinos in space and
time coincidence with the gamma-ray emission observed by IACTs has been performed using
ANTARES data. The search covers both the prompt and afterglow phases, yielding
no neutrinos in coincidence with the three GRBs studied. Upper limits on the energetics
of the neutrino emission are inferred. The resulting upper limits are several orders of
magnitude above the observed gamma-ray emission, and they do not allow to constrain the
available models.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MCI) and Agencia Estatal de Investigacion: Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -BC44) (MCI/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider, Junta de Andalucia (ref. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2021). ANTARES upper limits on the multi-TeV neutrino emission from the GRBs detected by IACTs. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. 2021(3):1-16. https://doi.org/10.1088/1475-7516/2021/03/092S1162021
Monte Carlo simulations for the ANTARES underwater neutrino telescope
[EN] Monte Carlo simulations are a unique tool to check the response of a detector
and to monitor its performance. For a deep-sea neutrino telescope, the variability of the
environmental conditions that can a ect the behaviour of the data acquisition system must
be considered, in addition to a reliable description of the active parts of the detector and of
the features of physics events, in order to produce a realistic set of simulated events. In this
paper, the software tools used to produce neutrino and cosmic ray signatures in the telescope
and the strategy developed to represent the time evolution of the natural environment and
of the detector e ciency are described.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariata l'energie atomique et auxenergies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MCI) and Agencia Estatal de Investigacion: Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -BC44) (MCI/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider, Junta de Andaluca (ref. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisola (ref. GRISOLIA/2018/119), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2021). Monte Carlo simulations for the ANTARES underwater neutrino telescope. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. 2021(1):1-19. https://doi.org/10.1088/1475-7516/2021/01/064S1192021
Non-Perturbative QCD Treatment of High-Energy Hadron-Hadron Scattering
Total cross-sections and logarithmic slopes of the elastic scattering
cross-sections for different hadronic processes are calculated in the framework
of the model of the stochastic vacuum. The relevant parameters of this model, a
correlation length and the gluon condensate, are determined from scattering
data, and found to be in very good agreement with values coming from completely
different sources of information. A parameter-free relation is given between
total cross-sections and slope parameters, which is shown to be remarkably
valid up to the highest energies for which data exist.Comment: 60 pages, Heidelberg preprin
Hint for a TeV neutrino emission from the Galactic Ridge with ANTARES
[EN] Interactions of cosmic ray protons, atomic nuclei, and electrons in the interstellar medium in the inner part of the Milky Way produce gamma-ray flux from the Galactic Ridge. If the gamma-ray emission is dominated by proton and nuclei interactions, a neutrino flux comparable to the gamma-ray flux is expected from the same sky region.
Data collected by the ANTARES neutrino telescope are used to constrain the neutrino flux from the Galactic Ridge in the 1-100 TeV energy range. Neutrino events reconstructed both as tracks and showers are considered in the analysis and the selection is optimized for the search of an excess in the region |l| < 30 degrees, |b| < 2 degrees. The expected background in the search region is estimated using an off-zone region with similar sky coverage. Neutrino signal originating from a power-law spectrum with spectral index ranging from Gamma nu = 1to 4is simulated in both channels. The observed energy distributions are fitted to constrain the neutrino emission from the Ridge.
The energy distributions in the signal region are inconsistent with the background expectation at similar to 96% confidence level. The mild excess over the background is consistent with a neutrino flux with a power law with a spectral index 2.45(-0.34)(+0.22) and a flux normalization dN nu/dE nu= 4.0(-2.0)(+2.7) x 10(-16) GeV-1 cm(-2) s(-1) sr(-1) at 40 TeV reference energy. Such flux is consistent with the expected neutrino signal if the bulk of the observed gamma-ray flux from the Galactic Ridge originates from interactions of cosmic ray protons and nuclei with a power-law spectrum extending well into the PeV energy range.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Labex UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Region Alsace (contrat CPER), Region Provence-Alpes-Cpte d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fuer Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 754496, Italy; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Grants PID2021-124591NB-C41,-C42,-C43 funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by "ERDF A way of making Europe", by the "European Union" or by the "European Union NextGenerationEU/PRTR", Programa de Planes Complementarios I+D+I (refs. ASFAE/2022/023, ASFAE/2022/014), Programa Prometeo (PROMETEO/2020/019) and GenT (refs. CIDE-GENT/2018/034,/2019/043,/2020/049./2021/23) of the Generalitat Valenciana, Junta de Andalucia (ref. P18-FR-5057), EU: MSC program (ref. 101025085), Programa Maria Zambrano (Spanish Ministry of Universities, funded by the European Union, NextGenerationEU), Spain; Ministry of Higher Education, Scientific Research and Training, Morocco, and the Arab Fund for Economic and Social Development, Kuwait. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Alves, S.; Andre, M.; Ardid, M.; Ardid, S.; Aubert, J.; Aublin, J.... (2023). Hint for a TeV neutrino emission from the Galactic Ridge with ANTARES. Physics Letters B. 841. https://doi.org/10.1016/j.physletb.2023.13795184
The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events
The design, construction, and commissioning of the ALICE Time-Projection
Chamber (TPC) is described. It is the main device for pattern recognition,
tracking, and identification of charged particles in the ALICE experiment at
the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and
is operated in a 0.5 T solenoidal magnetic field parallel to its axis.
In this paper we describe in detail the design considerations for this
detector for operation in the extreme multiplicity environment of central
Pb--Pb collisions at LHC energy. The implementation of the resulting
requirements into hardware (field cage, read-out chambers, electronics),
infrastructure (gas and cooling system, laser-calibration system), and software
led to many technical innovations which are described along with a presentation
of all the major components of the detector, as currently realized. We also
report on the performance achieved after completion of the first round of
stand-alone calibration runs and demonstrate results close to those specified
in the TPC Technical Design Report.Comment: 55 pages, 82 figure
- …