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Author Franca, U.; Lineros, R.A.; Palacio, J.; Pastor, S.
Title Probing interactions within the dark matter sector via extra radiation contributions Type Journal Article
Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 87 Issue 12 Pages (down) 123521 - 6pp
Keywords
Abstract The nature of dark matter is one of the most thrilling riddles for both cosmology and particle physics nowadays. While in the typical models the dark sector is composed only by weakly interacting massive particles, an arguably more natural scenario would include a whole set of gauge interactions which are invisible for the standard model but that are in contact with the dark matter. We present a method to constrain the number of massless gauge bosons and other relativistic particles that might be present in the dark sector using current and future cosmic microwave background data, and provide upper bounds on the size of the dark sector. We use the fact that the dark matter abundance depends on the strength of the interactions with both sectors, which allows one to relate the freeze-out temperature of the dark matter with the temperature of this cosmic background of dark gauge bosons. This relation can then be used to calculate how sizable is the impact of the relativistic dark sector in the number of degrees of freedom of the early Universe, providing an interesting and testable connection between cosmological data and direct/indirect detection experiments. The recent Planck data, in combination with other cosmic microwave background experiments and baryonic acoustic oscillations data, constrains the number of relativistic dark gauge bosons, when the freeze-out temperature of the dark matter is larger than the top mass, to be N less than or similar to 14 for the simplest scenarios, while those limits are slightly relaxed for the combination with the Hubble constant measurements to N less than or similar to 20. Future releases of Planck data are expected to reduce the uncertainty by approximately a factor of 3, which will reduce significantly the parameter space of allowed models.
Address [Franca, Urbano; Lineros, Roberto A.; Palacio, Joaquim; Pastor, Sergio] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia 46071, Spain
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000320765300005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1487
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Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Search for ultrahigh energy neutrinos in highly inclined events at the Pierre Auger Observatory Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal
Volume 84 Issue 12 Pages (down) 122005
Keywords
Abstract The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavors above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated systematic uncertainties. No candidate neutrinos have been found in data collected from 1 January 2004 to 31 May 2010. Assuming an E(-2) differential energy spectrum the limit on the single-flavor neutrino is E(2)dN/dE < 1.74 x 10(-7)GeVcm(-2)s(-1)sr(-1) at 90% C.L. in the energy range 1 x 10(17) eV < E < 1 x 10(20)eV.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000298667100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 863
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Author Pierre Auger Collaboration (Abraham, J. et al); Pastor, S.
Title Measurement of the Depth of Maximum of Extensive Air Showers above 10(18) eV Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 104 Issue 9 Pages (down) 091101 - 7pp
Keywords
Abstract We describe the measurement of the depth of maximum, X-max, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10(18) eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +/- 35-21) g/cm(2)/decade below 10(18.24) +/- (0.05) eV, and d24 +/- 3 g/cm(2)/ecade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm(2). The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
Address [Abraham, J.; De la Vega, G.; Garcia, B.; Videla, M.] Natl Technol Univ, Fac Mendoza, CONICET, CNEA, Mendoza, Argentina
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 ISI:000275252500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 490
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Author Lesgourgues, J.; Pastor, S.
Title Neutrino cosmology and Planck Type Journal Article
Year 2014 Publication New Journal of Physics Abbreviated Journal New J. Phys.
Volume 16 Issue Pages (down) 065002 - 24pp
Keywords neutrino masses; cosmology; dark matter
Abstract Relic neutrinos play an important role in the evolution of the Universe, modifying some of the cosmological observables. We summarize the main aspects of cosmological neutrinos and describe how the precision of present cosmological data can be used to learn about neutrino properties. In particular, we discuss how cosmology provides information on the absolute scale of neutrino masses, complementary to beta decay and neutrinoless double-beta decay experiments. We explain why the combination of Planck temperature data with measurements of the baryon acoustic oscillation angular scale provides a strong bound on the sum of neutrino masses, 0.23 eV at the 95% confidence level, while the lensing potential spectrum and the cluster mass function measured by Planck are compatible with larger values. We also review the constraints from current data on other neutrino properties. Finally, we describe the very good perspectives from future cosmological measurements, which are expected to be sensitive to neutrino masses close to the minimum values guaranteed by flavour oscillations.
Address [Lesgourgues, Julien] Ecole Polytech Fed Lausanne, Inst Theorie Phenomenes Phys, CH-1015 Lausanne, Switzerland, Email: Julien.Lesgourgues@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 1367-2630 ISBN Medium
Area Expedition Conference
Notes WOS:000339083500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1854
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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 (down) 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 [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