|   | 
Details
   web
Records
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 (down) 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 Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000295198300005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 779
Permanent link to this record
 

 
Author Serenelli, A.M.; Haxton, W.C.; Pena-Garay, C.
Title Solar Models With Accretion. I. Application To The Solar Abundance Problem Type Journal Article
Year 2011 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 743 Issue 1 Pages 24 - 20pp
Keywords (down) accretion, accretion disks; neutrinos; Sun: abundances; Sun: helioseismology; Sun: interior
Abstract We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. The status of the solar abundance problem is discussed. We investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate this problem. We examine a broad range of models, analyzing metal-enriched and metal-depleted accretion and three scenarios for the timing of accretion. Only partial solutions are found. Formetal-rich accreted material (Z(ac) greater than or similar to 0.018) there exist combinations of accreted mass and metallicity that bring the depth of the convective zone into agreement with the helioseismic value. For the surface helium abundance, the helioseismic value is reproduced if metal-poor or metal-free accretion is assumed (Z(ac) less than or similar to 0.09). In both cases a few percent of the solar mass must be accreted. Precise values depend on when accretion takes place. We do not find a simultaneous solution to both problems but speculate that changing the hydrogen-to-helium mass ratio in the accreted material may lead to more satisfactory solutions. We also show that, with current data, solar neutrinos are already a very competitive source of information about the solar core and can help constraining possible accretion histories. Even without helioseismic constraints, solar neutrinos rule out the possibility that more than 0.02 M(circle dot) from the protoplanetary disk were accreted after the Sun settled on the main sequence. Finally, we discuss how measurements of neutrinos from the CN cycle could shed light on the interaction between the early Sun and its protoplanetary disk.
Address [Serenelli, Aldo M.] Fac Ciencias, CSIC IEEC, Inst Ciencias Espacio, Bellaterra 08193, Spain
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 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000297408300024 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 857
Permanent link to this record
 

 
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 (down)
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 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:000296285800007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 793
Permanent link to this record
 

 
Author Minakata, H.; Pena-Garay, C.
Title Solar Neutrino Observables Sensitive to Matter Effects Type Journal Article
Year 2012 Publication Advances in High Energy Physics Abbreviated Journal Adv. High. Energy Phys.
Volume 2012 Issue Pages 349686 - 15pp
Keywords (down)
Abstract We discuss constraints on the coefficient A(MSW) which is introduced to simulate the effect of weaker or stronger matter potential for electron neutrinos with the current and future solar neutrino data. The currently available solar neutrino data leads to a bound A(MSW) = 1.47(+0.54)(-0.42)((-0.82)(+1.88)) at 1 sigma (3 sigma) CL, which is consistent with the Standard Model prediction A(MSW) = 1. For weaker matter potential (A(MSW) < 1), the constraint which comes from the flat B-8 neutrino spectrum is already very tight, indicating the evidence for matter effects. However for stronger matter potential (A(MSW) > 1), the bound is milder and is dominated by the day-night asymmetry of B-8 neutrino flux recently observed by Super-Kamiokande. Among the list of observables of ongoing and future solar neutrino experiments, we find that (1) an improved precision of the day-night asymmetry of B-8 neutrinos, (2) precision measurements of the low-energy quasi-monoenergetic neutrinos, and (3) the detection of the upturn of the B-8 neutrino spectrum at low energies are the best choices to improve the bound on A(MSW).
Address [Minakata, H.] Tokyo Metropolitan Univ, Dept Phys, Hachioji, Tokyo 1920397, Japan, Email: hisakazu.minakata@gmail.com
Corporate Author Thesis
Publisher Hindawi Publishing Corporation Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1687-7357 ISBN Medium
Area Expedition Conference
Notes WOS:000311152600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1234
Permanent link to this record
 

 
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 (down)
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 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:000314685400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1328
Permanent link to this record