| Records |
| 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 |
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Volume  |
84 |
Issue |
12 |
Pages |
122005 |
| Keywords |
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| 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. |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000298667100001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
863 |
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| Author |
Castorina, E.; Franca, U.; Lattanzi, M.; Lesgourgues, J.; Mangano, G.; Melchiorri, A.; Pastor, S. |
| Title |
Cosmological lepton asymmetry with a nonzero mixing angle theta(13) |
Type |
Journal Article |
| Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
86 |
Issue |
2 |
Pages |
023517 - 11pp |
| Keywords |
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| Abstract |
While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle theta(13), and show that for large theta(13) the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from big bang nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of theta(13). Finally, we perform a forecast for Cosmic Origins Explorer, taken as an example of a future cosmic microwave background experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 6.6. |
| Address |
[Castorina, Emanuele] SISSA, I-34136 Trieste, Italy |
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Thesis |
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| Publisher |
Amer Physical Soc |
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| Language |
English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000306320000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1093 |
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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 |
123521 - 6pp |
| Keywords |
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| 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 |
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Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000320765300005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
1487 |
| Permanent link to this record |
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| Author |
Pierre Auger Collaboration (Aab, A. et al); Pastor, S. |
| Title |
Probing the radio emission from air showers with polarization measurements |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
89 |
Issue |
5 |
Pages |
052002 - 18pp |
| Keywords |
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| Abstract |
The emission of radio waves from air showers has been attributed to the so-called geomagnetic emission process. At frequencies around 50 MHz this process leads to coherent radiation which can be observed with rather simple setups. The direction of the electric field induced by this emission process depends only on the local magnetic field vector and on the incoming direction of the air shower. We report on measurements of the electric field vector where, in addition to this geomagnetic component, another component has been observed that cannot be described by the geomagnetic emission process. The data provide strong evidence that the other electric field component is polarized radially with respect to the shower axis, in agreement with predictions made by Askaryan who described radio emission from particle showers due to a negative charge excess in the front of the shower. Our results are compared to calculations which include the radiation mechanism induced by this charge-excess process. |
| Address |
[Aab, A.; Buchholz, P.; Foerster, N.; Froehlich, U.; Homola, P.; Niechciol, M.; Pontz, M.; Risse, M.; Settimo, M.; Ziolkowski, M.] Univ Siegen, D-57068 Siegen, Germany |
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Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000333105200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1739 |
| Permanent link to this record |
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| Author |
Pierre Auger Collaboration (Aab, A. et al); Pastor, S. |
| Title |
Muons in air showers at the Pierre Auger Observatory: Measurement of atmospheric production depth |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
90 |
Issue |
1 |
Pages |
012012 - 15pp |
| Keywords |
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| Abstract |
The surface detector array of the Pierre Auger Observatory provides information about the longitudinal development of the muonic component of extensive air showers. Using the timing information from the flash analog-to-digital converter traces of surface detectors far from the shower core, it is possible to reconstruct a muon production depth distribution. We characterize the goodness of this reconstruction for zenith angles around 60 degrees and different energies of the primary particle. From these distributions, we define X-max(mu) as the depth along the shower axis where the production of muons reaches maximum. We explore the potentiality of X-max(mu) as a useful observable to infer the mass composition of ultrahigh-energy cosmic rays. Likewise, we assess its ability to constrain hadronic interaction models. |
| Address |
[Aab, A.; Buchholz, P.; Erfani, M.; Froehlich, U.; Heimann, P.; Homola, P.; Niechciol, M.; Ochilo, L.; Risse, M.; Yushkov, A.; Ziolkowski, M.] Univ Siegen, D-57068 Siegen, Germany |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000339922100001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1866 |
| Permanent link to this record |
