Records |
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Di Valentino, E.; Giusarma, E.; Lattanzi, M.; Mena, O.; Melchiorri, A.; Silk, J. |
Title |
Cosmological axion and neutrino mass constraints from Planck 2015 temperature and polarization data |
Type |
Journal Article |
Year |
2016 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
752 |
Issue |
|
Pages |
182-185 |
Keywords |
|
Abstract |
Axions currently provide the most compelling solution to the strong CP problem. These particles may be copiously produced in the early universe, including via thermal processes. Therefore, relic axions constitute a hot dark matter component and their masses are strongly degenerate with those of the three active neutrinos, as they leave identical signatures in the different cosmological observables. In addition, thermal axions, while still relativistic states, also contribute to the relativistic degrees of freedom, parameterized via N-eff. We present the cosmological bounds on the relic axion and neutrino masses, exploiting the full Planck mission data, which include polarization measurements. In the mixed hot dark matter scenario explored here, we find the tightest and more robust constraint to date on the sum of the three active neutrino masses, Sigma m nu < 0.136eV at 95% CL, as it is obtained in the very well-known linear perturbation regime. The Planck Sunyaev-Zeldovich cluster number count data further tightens this bound, providing a 95% CL upper limit of Sigma m nu < 0.126 eV in this very same mixed hot dark matter model, a value which is very close to the expectations in the inverted hierarchical neutrino mass scenario. Using this same combination of data sets we find the most stringent bound to date on the thermal axion mass, m(a) < 0.529 eV at 95% CL. |
Address |
[Di Valentino, Eleonora; Silk, Joseph] CNRS, UMR7095, Inst Astrophys Paris, F-75014 Paris, France, Email: elena.giusarma@roma1.infn.it |
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:000368026000026 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2524 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Di Valentino, E.; Giusarma, E.; Mena, O.; Melchiorri, A.; Silk, J. |
Title |
Cosmological limits on neutrino unknowns versus low redshift priors |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
93 |
Issue |
8 |
Pages |
083527 - 11pp |
Keywords |
|
Abstract |
Recent cosmic microwave background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses as well as the bounds on extended models with massless or massive sterile neutrino states. However, due to parameter degeneracies, additional low redshift priors are mandatory in order to sharpen the CMB neutrino bounds. We explore here the role of different priors on low redshift quantities, such as the Hubble constant, the cluster mass bias, and the reionization optical depth tau. Concerning current priors on the Hubble constant and the cluster mass bias, the bounds on the neutrino parameters may differ appreciably depending on the choices adopted in the analyses. With regard to future improvements in the priors on the reionization optical depth, a value of tau = 0.05 +/- 0.01, motivated by astrophysical estimates of the reionization redshift, would lead to Sigma m(nu) < 0.0926 eV at 90% C.L., when combining the full Planck measurements, baryon acoustic oscillation, and Planck clusters data, thereby opening the window to unravel the neutrino mass hierarchy with existing cosmological probes. |
Address |
[Di Valentino, Eleonora; Silk, Joseph] CNRS, Inst Astrophys Paris, UMR7095, F-75014 Paris, France |
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 |
2470-0010 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000375203600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2643 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Dias, J.M.; Navarra, F.S.; Nielsen, M.; Oset, E. |
Title |
f(0)(980) production in D-s(+)-> pi(+) pi(+) pi(-) and D-s(+) -> pi(+) K+ K- decays |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
94 |
Issue |
9 |
Pages |
096002 - 8pp |
Keywords |
|
Abstract |
We study the D-s(+)-> pi(+) pi(+) pi(-) and D-s(+) -> pi(+) K+ K- decays adopting a mechanism in which the D-s(+) meson decays weakly into a pi+ and a q (q) over bar component, which hadronizes into two pseudoscalar mesons. The final state interaction between these two pseudoscalar mesons is taken into account by using the chiral unitary approach in coupled channels, which gives rise to the f(0)(980) resonance. Hence, we obtain the invariant mass distributions of the pairs pi(+) pi(-) and K+ K- after the decay of that resonance and compare our theoretical amplitudes with those available from the experimental data. Our results are in a fair agreement with the shape of these data, within large experimental uncertainty, and a f(0)(980) signal is seen in both the pi(+) pi(-) and K+ K- distributions. Predictions for the relative size of pi(+) pi(-) and K+ K- distributions are made. |
Address |
[Dias, J. M.; Navarra, F. S.; Nielsen, M.] Univ Sao Paulo, Inst Fis, CP 66318, BR-05389970 Sao Paulo, SP, Brazil, Email: jdias@if.usp.br; |
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 |
2470-0010 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000386896900006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2843 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Domingo-Pardo, C. |
Title |
Beta-delayed neutron emission: first measurements in the heavy mass region and future prospects |
Type |
Journal Article |
Year |
2016 |
Publication |
Acta Physica Polonica B |
Abbreviated Journal |
Acta Phys. Pol. B |
Volume |
47 |
Issue |
3 |
Pages |
729-737 |
Keywords |
|
Abstract |
Beta-delayed neutrons play a key role in the formation of heavy elements in explosive stellar environments. The final r-process abundance distribution, including the rare-earth peak, is tailored to a large extent by the neutrons released after the beta decay of very exotic neutron-rich nuclei encountered along the r-process path and during the freeze-out phase. Such scenarios involve a vast amount of – yet undiscovered – nuclei, and most of them are expected to be neutron emitters. In this respect, existing beta-delayed neutron emission data is rather scarce, spanning from the lightest isotopes up to the region of the fission-fragments with masses up to A similar to 150. This contribution gives an overview on the latest measurements of neutron branching ratios in the heavy mass region around N = 126, which was practically unexplored in the past. Present plans to access very exotic nuclei at the RIB-facility of RIKEN in the framework of the BRIKEN project, are presented, together with the expected impact in r-process nucleosynthesis studies. |
Address |
[Domingo-Pardo, C.; S410 GSI Collaboration; BRIKEN Collaboration] Univ Valencia, CSIC, IFIC, Valencia, Spain |
Corporate Author |
|
Thesis |
|
Publisher |
Wydawnictwo Uniwersytetu Jagiellonskiego |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0587-4254 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000373495500015 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2623 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Domingo-Pardo, C. |
Title |
i-TED: A novel concept for high-sensitivity (n,gamma) cross-section measurements |
Type |
Journal Article |
Year |
2016 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
825 |
Issue |
|
Pages |
78-86 |
Keywords |
Radiative neutron capture; Neutron time-of-flight; Cross-section; Pulse-height weighting technique; Compton imaging |
Abstract |
A new method for measuring (n, gamma) cross-sections aiming at enhanced signal-to-background ratio is presented. This new approach is based on the combination of the pulse-height weighting technique with a total energy detection system that features gamma-ray imaging capability (i-TED). The latter allows one to exploit Compton imaging techniques to discriminate between true capture gamma-rays arising from the sample under study and background gamma-rays coming from contaminant neutron (prompt or delayed) captures in the surrounding environment. A general proof-of-concept detection system for this application is presented in this paper together with a description of the imaging method and a conceptual demonstration based on Monte Carlo simulations. |
Address |
[Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46003 Valencia, Spain |
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 |
0168-9002 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000376713700010 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2686 |
Permanent link to this record |