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Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Interpretation of the depths of maximum of extensive air showers measured by the Pierre Auger Observatory Type Journal Article
Year 2013 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages 026 - 20pp
Keywords ultra high energy cosmic rays; cosmic ray experiments
Abstract To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.
Address [Allekotte, I.; Asorey, H.; Bertou, X.; Golup, G.; Gomez Berisso, M.; Harari, D.; Mollerach, S.; Ponce, V. H.; Roulet, E.; Santo, C. E.; Sidelnik, I.] Ctr Atom Bariloche, San Carlos De Bariloche, Rio Negro, Argentina
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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000315576400026 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1360
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Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory Type Journal Article
Year 2013 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 05 Issue 5 Pages 009 - 19pp
Keywords ultra high energy cosmic rays; cosmic ray experiments
Abstract We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than similar to (0.06 – 5) x 10(-4) Mpc(-3) at 95% CL, depending on the magnitude of the magnetic defections. Similar bounds, in the range (0.2 – 7) x 10(-4) Mpc(-3), were obtained for sources following the local matter distribution.
Address [Allekotte, I.; Asorey, H.; Bertou, X.; Golup, G.; Gomez Berisso, M.; Harari, D.; Mollerach, S.; Ponce, V. H.; Roulet, E.; Sidelnik, I.] Ctr Atom Bariloche, San Carlos De Bariloche, Rio Negro, Argentina, 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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000320161400011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1497
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Author Pierre Auger Collaboration (Aab, A. et al); Pastor, S.
Title Reconstruction of inclined air showers detected with the pierre Auger Observatory Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages 019 - 32pp
Keywords ultra high energy cosmic rays; cosmic ray experiments
Abstract We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60 degrees detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.
Address [Anchordoqui, L.] CUNY, CUNY Herbert H Lehman Coll, Dept Phys & Astron, New York, NY 10021 USA
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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000341848800019 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1942
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Author de Salas, P.F.; Pastor, S.
Title Relic neutrino decoupling with flavour oscillations revisited Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 051 - 18pp
Keywords cosmological neutrinos; particle physics – cosmology connection; physics of the; early universe; neutrino properties
Abstract We study the decoupling process of neutrinos in the early universe in the presence of three-flavour oscillations. The evolution of the neutrino spectra is found by solving the corresponding momentum-dependent kinetic equations for the neutrino density matrix, including for the first time the proper collision integrals for both diagonal and off-diagonal elements. This improved calculation modifies the evolution of the off-diagonal elements of the neutrino density matrix and changes the deviation from equilibrium of the frozen neutrino spectra. However, it does not vary the contribution of neutrinos to the cosmological energy density in the form of radiation, usually expressed in terms of the effective number of neutrinos, N-eff. We find a value of N-eff = 3.045, in agreement with previous theoretical calculations and consistent with the latest analysis of Planck data. This result does not depend on the ordering of neutrino masses. We also consider the effect of non-standard neutrino-electron interactions (NSI), predicted in many theoretical models where neutrinos acquire mass. For two sets of NSI parameters allowed by present data, we find that Neff can be reduced down to 3.040 or enhanced up to 3.059.
Address [de Salas, Pablo F.; Pastor, Sergio] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient UV,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: pabrerde@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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000381830000052 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2784
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Author Adhikari, R. et al; Pastor, S.; Valle, J.W.F.
Title A White Paper on keV sterile neutrino Dark Matter Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 01 Issue 1 Pages 025 - 247pp
Keywords cosmological neutrinos; dark matter experiments; dark matter theory; particle physics – cosmology connection
Abstract We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved – cosmology, astrophysics, nuclear, and particle physics – in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.
Address [Drewes, M.; Ibarra, A.; Lasserre, T.; Oberauer, L.; Schoenert, S.] Tech Univ Munich, Phys Dept & Excellence Cluster Univ, James Franck Str 1, D-85748 Garching, Germany, Email: marcodrewes@gmail.com;
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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000399409800025 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3109
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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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000411617000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3308
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Author de Salas, P.F.; Gariazzo, S.; Laveder, M.; Pastor, S.; Pisanti, O.; Truong, N.
Title Cosmological bounds on neutrino statistics Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages 050 - 18pp
Keywords cosmological neutrinos; neutrino properties; big bang nucleosynthesis; cosmological parameters from CMBR
Abstract We consider the phenomenological implications of the violation of the Pauli exclusion principle for neutrinos, focusing on cosmological observables such as the spectrum of Cosmic Microwave Background anisotropies, Baryon Acoustic Oscillations and the primordial abundances of light elements. Neutrinos that behave (at least partly) as bosonic particles have a modified equilibrium distribution function that implies a different influence on the evolution of the Universe that, in the case of massive neutrinos, can not be simply parametrized by a change in the effective number of neutrinos. Our results show that, despite the precision of the available cosmological data, only very weak bounds can be obtained on neutrino statistics, disfavouring a more bosonic behaviour at less than 2 sigma.
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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000428984100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3551
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Author Gariazzo, S.; de Salas, P.F.; Pastor, S.
Title Thermalisation of sterile neutrinos in the early universe in the 3+1 scheme with full mixing matrix Type Journal Article
Year 2019 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 014 - 30pp
Keywords cosmological neutrinos; neutrino properties; particle physics – cosmology connection; physics of the early universe
Abstract In the framework of a 3+1 scheme with an additional inert state, we consider the thermalisation of sterile neutrinos in the early Universe taking into account the full 4 x 4 mixing matrix. The evolution of the neutrino energy distributions is found solving the momentum-dependent kinetic equations with full diagonal collision terms, as in previous analyses of flavour neutrino decoupling in the standard case. The degree of thermalisation of the sterile state is shown in terms of the effective number of neutrinos, N-eff, and its dependence on the three additional mixing angles (theta(14), theta(24), theta(34)) and on the squared mass difference Delta m(41)(2) is discussed. Our results are relevant for fixing the contribution of a fourth light neutrino species to the cosmological energy density, whose value is very well constrained by the final Planck analysis. For the preferred region of active-sterile mixing parameters from short-baseline neutrino experiments, we find that the fourth state is fully thermalised (N-eff similar or equal to 4).
Address [Gariazzo, S.; Pastor, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: gariazzo@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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000474782100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4076
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Author PTOLEMY Collaboration (Betti, M.G. et al); Gariazzo, S.; Pastor, S.
Title Neutrino physics with the PTOLEMY project: active neutrino properties and the light sterile case Type Journal Article
Year 2019 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 047 - 31pp
Keywords cosmological neutrinos; neutrino detectors; particle physics – cosmology connection; physics of the early universe
Abstract The PTOLEMY project aims to develop a scalable design for a Cosmic Neutrino Background (CNB) detector, the first of its kind and the only one conceived that can look directly at the image of the Universe encoded in neutrino background produced in the first second after the Big Bang. The scope of the work for the next three years is to complete the conceptual design of this detector and to validate with direct measurements that the non-neutrino backgrounds are below the expected cosmological signal. In this paper we discuss in details the theoretical aspects of the experiment and its physics goals. In particular, we mainly address three issues. First we discuss the sensitivity of PTOLEMY to the standard neutrino mass scale. We then study the perspectives of the experiment to detect the CNB via neutrino capture on tritium as a function of the neutrino mass scale and the energy resolution of the apparatus. Finally, we consider an extra sterile neutrino with mass in the eV range, coupled to the active states via oscillations, which has been advocated in view of neutrino oscillation anomalies. This extra state would contribute to the tritium decay spectrum, and its properties, mass and mixing angle, could be studied by analyzing the features in the beta decay electron spectrum.
Address [Betti, M. G.; Cavoto, G.; Mancini-Terracciano, C.; Mariani, C.; Polosa, A. D.; Rago, I] Univ Roma La Sapienza, Rome, Italy, Email: pabferde@gmail.com;
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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000478735300006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4097
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Author Mertsch, P.; Parimbelli, G.; de Salas, P.F.; Gariazzo, S.; Lesgourgues, J.; Pastor, S.
Title Neutrino clustering in the Milky Way and beyond Type Journal Article
Year 2020 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 01 Issue 1 Pages 015 - 23pp
Keywords cosmological neutrinos; galaxy clustering; cosmological simulations
Abstract The standard cosmological model predicts the existence of a Cosmic Neutrino Background, which has not yet been observed directly. Some experiments aiming at its detection are currently under development, despite the tiny kinetic energy of the cosmological relic neutrinos, which makes this task incredibly challenging. Since massive neutrinos are attracted by the gravitational potential of our Galaxy, they can cluster locally. Neutrinos should be more abundant at the Earth position than at an average point in the Universe. This fact may enhance the expected event rate in any future experiment. Past calculations of the local neutrino clustering factor only considered a spherical distribution of matter in the Milky Way and neglected the influence of other nearby objects like the Virgo cluster, although recent N-body simulations suggest that the latter may actually be important. In this paper, we adopt a back-tracking technique, well established in the calculation of cosmic rays fluxes, to perform the first three-dimensional calculation of the number density of relic neutrinos at the Solar System, taking into account not only the matter composition of the Milky Way, but also the contribution of the Andromeda galaxy and the Virgo cluster. The effect of Virgo is indeed found to be relevant and to depend non-trivially on the value of the neutrino mass. Our results show that the local neutrino density is enhanced by 0.53% for a neutrino mass of 10 meV, 12% for 50 meV, 50% for 100 meV or 500% for 300 meV.
Address [Mertsch, P.; Lesgourgues, J.] Rhein Westfal TH Aachen, Inst Theoret Particle Phys & Cosmol TTK, D-52056 Aachen, Germany, Email: pmertsch@physik.rwth-aachen.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 (down) 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000528025800016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4382
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