Records |
Author |
Bustamante, M.; Gago, A.M.; Pena-Garay, C. |
Title |
Energy-independent new physics in the flavour ratios of high-energy astrophysical neutrinos |
Type |
Journal Article |
Year |
2010 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
04 |
Issue |
4 |
Pages |
066 - 28pp |
Keywords |
Beyond Standard Model; Neutrino Physics; Discrete and Finite Symmetries |
Abstract |
We have studied the consequences of breaking the CPT symmetry in the neutrino sector, using the expected high-energy neutrino flux from distant cosmological sources such as active galaxies. For this purpose we have assumed three different hypotheses for the neutrino production model, characterised by the flavour fluxes at production phi(0)(e) : phi(0)(mu) : phi(0)(tau) = 1 : 2 : 0, 0 : 1 : 0, and 1 : 0 : 0, and studied the theoretical and experimental expectations for the muon-neutrino flux at Earth, phi(mu), and for the flavour ratios at Earth, R = phi(mu)/phi(e) and S = phi(tau)/phi(mu). CPT violation (CPTV) has been implemented by adding an energy-independent term to the standard neutrino oscillation Hamiltonian. This introduces three new mixing angles, two new eigenvalues and three new phases, all of which have currently unknown values. We have varied the new mixing angles and eigenvalues within certain bounds, together with the parameters associated to pure standard oscillations. Our results indicate that, for the models 1 : 2 : 0 and 0 : 1 : 0, it might be possible to find large deviations of phi(mu), R, and S between the cases without and with CPTV, provided the CPTV eigenvalues lie within 10(-29) – 10(-27) GeV, or above. Moreover, if CPTV exists, there are certain values of R and S that can be accounted for by up to three production models. If no CPTV were observed, we could set limits on the CPTV eigenvalues of the same order. Detection prospects calculated using IceCube suggest that for the models 1 : 2 : 0 and 0 : 1 : 0, the modifications due to CPTV are larger and more clearly separable from the standard-oscillations predictions. We conclude that IceCube is potentially able to detect CPTV but that, depending on the values of the CPTV parameters, there could be a mis-determination of the neutrino production model. |
Address |
[Bustamante, M.; Gago, A. M.] Univ Catolica Peru, Secc Fis, Dept Ciencias, Lima, Peru, Email: mbustamante@pucp.edu.pe |
Corporate Author |
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Thesis |
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Publisher |
Springer |
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 Volume |
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Series Issue |
|
Edition |
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ISSN |
1126-6708 |
ISBN |
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Medium |
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Area |
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Expedition |
|
Conference |
|
Notes |
ISI:000277473100004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
455 |
Permanent link to this record |
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Author |
Bergstrom, J.; Gonzalez-Garcia, M.C.; Maltoni, M.; Pena-Garay, C.; Serenelli, A.M.; Song, N.Q. |
Title |
Updated determination of the solar neutrino fluxes from solar neutrino data |
Type |
Journal Article |
Year |
2016 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
03 |
Issue |
3 |
Pages |
132 - 19pp |
Keywords |
Neutrino Physics; Solar and Atmospheric Neutrinos |
Abstract |
We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions. |
Address |
[Bergstroem, Johannes; Gonzalez-Garcia, M. C.] Univ Barcelona, Dept Estruct & Constituents Mat, Diagonal 647, E-08028 Barcelona, Spain, Email: bergstrom@ecm.ub.edu; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
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 Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000373050700004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2609 |
Permanent link to this record |
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|
Author |
Norena, J.; Verde, L.; Jimenez, R.; Pena-Garay, C.; Gomez, C. |
Title |
Cancelling out systematic uncertainties |
Type |
Journal Article |
Year |
2012 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
Volume |
419 |
Issue |
2 |
Pages |
1040-1050 |
Keywords |
methods: statistical; cosmology: theory |
Abstract |
We present a method to minimize, or even cancel out, the nuisance parameters affecting a measurement. Our approach is general and can be applied to any experiment or observation where systematic errors are a concern e.g. are larger than statistical errors. We compare it with the Bayesian technique used to deal with nuisance parameters: marginalization, and show how the method compares and improves by avoiding biases. We illustrate the method with several examples taken from the astrophysics and cosmology world: baryonic acoustic oscillations (BAOs), cosmic clocks, Type Ia supernova (SNIa) luminosity distance, neutrino oscillations and dark matter detection. By applying the method we not only recover some known results but also find some interesting new ones. For BAO experiments we show how to combine radial and angular BAO measurements in order to completely eliminate the dependence on the sound horizon at radiation drag. In the case of exploiting SNIa as standard candles we show how the uncertainty in the luminosity distance by a second parameter modelled as a metallicity dependence can be eliminated or greatly reduced. When using cosmic clocks to measure the expansion rate of the universe, we demonstrate how a particular combination of observables nearly removes the metallicity dependence of the galaxy on determining differential ages, thus removing the agemetallicity degeneracy in stellar populations. We hope that these findings will be useful in future surveys to obtain robust constraints on the dark energy equation of state. |
Address |
[Norena, Jorge; Verde, Licia; Jimenez, Raul] Univ Barcelona IEEC UB, ICREA, Barcelona 08028, Spain, Email: jorge.norena@icc.ub.edu |
Corporate Author |
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Thesis |
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Publisher |
Wiley-Blackwell |
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 Volume |
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Series Issue |
|
Edition |
|
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000298482300011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
890 |
Permanent link to this record |
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|
Author |
Serenelli, A.; Scott, P.; Villante, F.L.; Vincent, A.C.; Asplund, M.; Basu, S.; Grevesse, N.; Pena-Garay, C. |
Title |
Implications of solar wind measurements for solar models and composition |
Type |
Journal Article |
Year |
2016 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
Volume |
463 |
Issue |
1 |
Pages |
2-9 |
Keywords |
neutrinos; Sun: abundances; Sun: helioseismology; Sun: interior |
Abstract |
We critically examine recent claims of a high solar metallicity by von Steiger & Zurbuchen (2016, vSZ16) based onin situ measurements of the solar wind, rather than the standard spectroscopically inferred abundances (Asplund et al. 2009, hereafter AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar modelling problem. We show that, although some helioseismological observables are improved compared to models computed with spectroscopic abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted B-8 flux that is nearly twice its observed value, and Be-7 and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances are worse than AGSS09 despite a higher metallicity. We also present astrophysical and spectroscopic arguments showing the vSZ16 composition to be an implausible representation of the solar interior, identifying the first ionization potential effect in the outer solar atmosphere and wind as the likely culprit. |
Address |
[Serenelli, Aldo] Inst Space Sci IEEC CSIC, E-08193 Barcelona, Spain, Email: aldos@ice.csic.es |
Corporate Author |
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Thesis |
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Publisher |
Oxford Univ Press |
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 Volume |
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Series Issue |
|
Edition |
|
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000386464900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2842 |
Permanent link to this record |
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|
|
Author |
Serenelli, A.; Pena-Garay, C.; Haxton, W.C. |
Title |
Using the standard solar model to constrain solar composition and nuclear reaction S factors |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
87 |
Issue |
4 |
Pages |
043001 - 9pp |
Keywords |
|
Abstract |
While standard solar model (SSM) predictions depend on approximately 20 input parameters, SSM neutrino flux predictions are strongly correlated with a single model output parameter, the core temperature T-c. Consequently, one can extract physics from solar neutrino flux measurements while minimizing the consequences of SSM uncertainties, by studying flux ratios with appropriate power-law weightings tuned to cancel this T-c dependence. We reexamine an idea for constraining the primordial C + N content of the solar core from a ratio of CN-cycle O-15 to pp-chain B-8 neutrino fluxes, showing that non-nuclear SSM uncertainties in the ratio are small and effectively governed by a single parameter, the diffusion coefficient. We point out that measurements of both CN-I cycle neutrino branches-O-15 and N-13 beta-decay-could, in principle, lead to separate determinations of the core C and N abundances, due to out-of-equilibrium CN-cycle burning in the cooler outer layers of the solar core. Finally, we show that the strategy of constructing “minimum uncertainty” neutrino flux ratios can also test other properties of the SSM. In particular, we demonstrate that a weighted ratio of Be-7 and B-8 fluxes constrains a product of S-factors to the same precision currently possible with laboratory data. |
Address |
[Serenelli, Aldo] CSIC IEEC, Inst Ciencias Espacio, Fac Ciencies, Bellaterra 08193, Spain, Email: aldos@ice.csic.es; |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
|
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 Volume |
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Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000314685400001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1328 |
Permanent link to this record |
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|
Author |
Borexino Collaboration (Bellini, G. et al); Pena-Garay, C. |
Title |
Final results of Borexino Phase-I on low-energy solar neutrino spectroscopy |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
89 |
Issue |
11 |
Pages |
112007 - 68pp |
Keywords |
|
Abstract |
Borexino has been running since May 2007 at the Laboratori Nazionali del Gran Sasso laboratory in Italy with the primary goal of detecting solar neutrinos. The detector a large unsegmented liquid scintillator calorimeter characterized by unprecedented low levels of intrinsic radioactivity is optimized for the study of the lower energy part of the spectrum. During Phase-I (2007-2010) Borexino first detected and then precisely measured the flux of the Be-7 solar neutrinos ruled out any significant day-night asymmetry of their interaction rate made the first direct observation of the pep neutrinos and set the tightest upper limit on the flux of solar neutrinos produced in the CNO cycle (carbon nitrogen oxigen) where carbon nitrogen and oxygen serve as catalysts in the fusion process. In this paper we discuss the signal signature and provide a comprehensive description of the backgrounds quantify their event rates describe the methods for their identification selection or subtraction and describe data analysis. Key features are an extensive in situ calibration program using radioactive sources the detailed modeling of the detector response the ability to define an innermost fiducial volume with extremely low background via software cuts and the excellent pulse-shape discrimination capability of the scintillator that allows particle identification. We report a measurement of the annual modulation of the Be-7 neutrino interaction rate. The period the amplitude and the phase of the observed modulation are consistent with the solar origin of these events and the absence of their annual modulation is rejected with higher than 99% C.L. The physics implications of Phase-I results in the context of the neutrino oscillation physics and solar models are presented. |
Address |
[Bellini, G.; Avanzini, M. Buizza; Caccianiga, B.; D'Angelo, D.; Giammarchi, M.; Lombardi, P.; Ludhova, L.; Meroni, E.; Miramonti, L.; Ranucci, G.; Re, A.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy |
Corporate Author |
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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 Volume |
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Series Issue |
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Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000338663100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1856 |
Permanent link to this record |
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|
Author |
Caputo, A.; Pena-Garay, C.; Witte, S.J. |
Title |
Looking for axion dark matter in dwarf spheroidal galaxies |
Type |
Journal Article |
Year |
2018 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
98 |
Issue |
8 |
Pages |
083024 - 6pp |
Keywords |
|
Abstract |
We study the extent to which the decay of cold dark matter axions can be probed with forthcoming radio telescopes such as the Square Kilometer Array (SKA). In particular, we focus on signals arising from dwarf spheroidal galaxies, where astrophysical uncertainties are reduced and the expected magnetic field strengths are such that signals arising from axion decay may dominate over axion-photon conversion in a magnetic field. We show that with similar to 100 hr of observing time, SKA could improve current sensitivity by 2-3 orders of magnitude-potentially obtaining sufficient sensitivity to begin probing the decay of cold dark matter axions. |
Address |
[Caputo, Andrea; Witte, Samuel J.] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain |
Corporate Author |
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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 Volume |
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Series Issue |
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Edition |
|
ISSN |
2470-0010 |
ISBN |
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Medium |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:000448458600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
3788 |
Permanent link to this record |
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Author |
Borexino Collaboration (Bellini, G. et al); Pena-Garay, C. |
Title |
Precision Measurement of the (7)Be Solar Neutrino Interaction Rate in Borexino |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
107 |
Issue |
14 |
Pages |
141302 - 5pp |
Keywords |
|
Abstract |
The rate of neutrino-electron elastic scattering interactions from 862 keV (7)Be solar neutrinos in Borexino is determined to be 46.0 +/- 1.5(stat)(-1.6)(+1.5)(syst)counts/(day . 100 ton). This corresponds to a nu(e)-equivalent (7)Be solar neutrino flux of (3.10 +/- 0.15) x 10(9) cm(-2) s(-1) and, under the assumption of nu(e) transition to other active neutrino flavours, yields an electron neutrino survival probability of 0.51 +/- 0.07 at 862 keV. The no flavor change hypothesis is ruled out at 5.0 sigma. A global solar neutrino analysis with free fluxes determines Phi(pp) = 6.06(-0.66)(+0.02) x 10(10) cm(-2) s(-1) and Phi(CNO) < 1.3 x 10(9) cm(-2) s(-1) (95% C.L.). These results significantly improve the precision with which the Mikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy. |
Address |
[Bellini, G; Bonetti, S; Avanzini, MB; Caccianiga, B; D'Angelo, D; Giammarchi, M; Ludhova, L; Meroni, E; Miramonti, L; Perasso, L; Ranucci, G; Re, A] Univ Studi & INFN, Dipartimento Fis, I-20133 Milan, Italy |
Corporate Author |
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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 Volume |
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Series Issue |
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Edition |
|
ISSN |
0031-9007 |
ISBN |
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Medium |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:000296285800007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
793 |
Permanent link to this record |
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Author |
Jimenez, R.; Pena-Garay, C.; Verde, L. |
Title |
Is it possible to explore Peccei-Quinn axions from frequency-dependence radiation dimming? |
Type |
Journal Article |
Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
703 |
Issue |
3 |
Pages |
232-236 |
Keywords |
Axion; CF; White dwarf |
Abstract |
We explore how the Peccei-Quinn (PQ) axion parameter space can be constrained by the frequency-dependence dimming of radiation from astrophysical objects. To do so we perform accurate calculations of photon-axion conversion in the presence of a variable magnetic field. We propose several tests where the PQ axion parameter space can be explored with current and future astronomical surveys: the observed spectra of isolated neutron stars, occultations of background objects by white dwarfs and neutron stars, the light-curves of eclipsing binaries containing a white dwarf. We find that the lack of dimming of the light-curve of a detached eclipsing white dwarf binary recently observed, leads to relevant constraints on the photon-axion conversion. Current surveys designed for Earth-like planet searches are well matched to strengthen and improve the constraints on the PQ axion using astrophysical objects radiation dimming. |
Address |
[Jimenez, R; Verde, L] Univ Barcelona IEEC UB, ICREA & ICC, Barcelona 08028, Spain, Email: jimenez@icc.ub.edu |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
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 Volume |
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Series Issue |
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Edition |
|
ISSN |
0370-2693 |
ISBN |
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Medium |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:000295198300005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ elepoucu @ |
Serial |
779 |
Permanent link to this record |
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|
Author |
Borexino Collaboration (Bellini, G. et al); Pena-Garay, C. |
Title |
Absence of a day-night asymmetry in the Be-7 solar neutrino rate in Borexino |
Type |
Journal Article |
Year |
2012 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
707 |
Issue |
1 |
Pages |
22-26 |
Keywords |
Solar neutrinos; Day-night effect; CPT violation; Neutrino oscillations |
Abstract |
We report the result of a search for a day-night asymmetry in the Be-7 solar neutrino interaction rate in the Borexino detector at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The measured asymmetry is A(dn) = 0.001 +/- 0.012 (stat) +/- 0.007 (syst), in agreement with the prediction of MSW-LMA solution for neutrino oscillations. This result disfavors MSW oscillations with mixing parameters in the LOW region at more than 8.5 sigma. This region is, for the first time, strongly disfavored without the use of reactor anti-neutrino data and therefore the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics. |
Address |
[Carraro, C.; Davini, S.; Guardincerri, E.; Manuzio, G.; Pallavicini, M.; Perasso, S.; Salvo, C.; Testera, G.; Zavatarelli, S.] Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy, Email: marco.pallavicini@ge.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
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 Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000299757000004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
901 |
Permanent link to this record |