| Records |
Author  |
Vincent, A.C.; Fernandez Martinez, E.; Hernandez, P.; Mena, O.; Lattanzi, M. |
| Title |
Revisiting cosmological bounds on sterile neutrinos |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
006 - 23pp |
| Keywords |
particle physics – cosmology connection; cosmological neutrinos; cosmology of theories beyond the SM |
| Abstract |
We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R-CMB and the sound horizon r(s) from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin(2) theta less than or similar to 0.026(m(s)/eV)(-2). |
| Address |
[Vincent, Aaron C.] Univ Durham, Dept Phys, IPPP, Durham DH1 3LE, England, Email: aaron.vincent@durham.ac.uk; |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
1475-7516 |
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:000355742500007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2261 |
| Permanent link to this record |
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| Author |
Sandner, S.; Hernandez, P.; Lopez-Pavon, J.; Rius, N. |
| Title |
Predicting the baryon asymmetry with degenerate right-handed neutrinos |
Type |
Journal Article |
| Year |
2023 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
11 |
Issue |
11 |
Pages |
153 - 37pp |
| Keywords |
Baryo-and Leptogenesis; Sterile or Heavy Neutrinos; Early Universe Particle Physics |
| Abstract |
We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the observed matter-antimatter asymmetry, for masses of the heavy singlets below the electroweak scale. The only physical CP violating phases in the model are those in the PMNS mixing matrix, i.e. the Dirac phase and a Majorana phase that enter light neutrino observables. We present an accurate analytic approximation for the baryon asymmetry in terms of CP flavour invariants, and derive the correlations with neutrino observables. We demonstrate that the measurement of CP violation in neutrino oscillations as well as the mixings of the heavy neutral leptons with the electron, muon and tau flavours suffice to pin down the matter-antimatter asymmetry from laboratory measurements. |
| Address |
[Sandner, S.] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: stefan.sandner@ific.uv.es; |
| 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 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 |
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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:001111979900002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5869 |
| Permanent link to this record |
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| Author |
Lasa-Alonso, J.; Olmos-Trigo, J.; Devescovi, C.; Hernandez, P.; Garcia-Etxarri, A.; Molina-Terriza, G. |
| Title |
Resonant helicity mixing of electromagnetic waves propagating through matter |
Type |
Journal Article |
| Year |
2023 |
Publication |
Physical Review Research |
Abbreviated Journal |
Phys. Rev. Res. |
| Volume |
5 |
Issue |
2 |
Pages |
023116 - 8pp |
| Keywords |
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| Abstract |
Dual scatterers preserve the helicity of an incident field, whereas antidual scatterers flip it completely. In this setting of linear electromagnetic scattering theory, we provide a completely general proof on the nonexistence of passive antidual scatterers. However, we show that scatterers fulfilling the refractive index matching condition flip the helicity of the fields very efficiently without being in contradiction with the law of energy conservation. Moreover, we find that this condition is paired with the impedance matching condition in several contexts of electromagnetism and, in particular, within Fresnel's and Mie's scattering problems. Finally, we show that indexmatched media induce a resonant helicity mixing on the propagating electromagnetic waves. We reach this conclusion by identifying that the refractive index matching condition leads to the phenomenon of avoided crossing. |
| Address |
[Lasa-Alonso, Jon; Molina-Terriza, Gabriel] Ctr Fis Mat, Paseo Manuel Lardizabal 5, Donostia San Sebastian 20018, Spain, Email: jonqnanolab@gmail.com; |
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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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Abbreviated Series Title |
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Series Issue |
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Edition |
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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:000999546300002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5856 |
| Permanent link to this record |
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| Author |
Hernandez, P.; Romero-Lopez, F. |
| Title |
The large N-c limit of QCD on the lattice |
Type |
Journal Article |
| Year |
2021 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
| Volume |
57 |
Issue |
2 |
Pages |
52 - 19pp |
| Keywords |
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| Abstract |
We review recent progress in the study of the large N-c limit of gauge theories from lattice simulations. The focus is not only the planar limit but also the size of O(N-c(-1)) corrections for values of N-c greater than or similar to 3. Some concrete examples of the topics we include are tests of large- Nc factorization, the topological susceptibility, the glueball, meson and baryon spectra, the chiral dependence of masses and decay constants, and weak matrix elements related to the Delta I = 1/2 rule in kaon decays. |
| Address |
[Romero-Lopez, Fernando] Univ Valencia, Inst Fis Corpuscular, Valencia, Spain, Email: m.pilar.hernandez@uv.es; |
| 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 |
1434-6001 |
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:000617515000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4718 |
| Permanent link to this record |
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| Author |
Hernandez, P.; Pena, C.; Romero-Lopez, F. |
| Title |
Large Nc scaling of meson masses and decay constants |
Type |
Journal Article |
| Year |
2019 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
79 |
Issue |
10 |
Pages |
865 - 13pp |
| Keywords |
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| Abstract |
We perform an ab initio calculation of the Nc scaling of the low-energy couplings of the chiral Lagrangian of low-energy strong interactions, extracted from the mass dependence of meson masses and decay constants. We compute these observables on the lattice with four degenerate fermions, Nf=4, and varying number of colours, Nc=3-6, at a lattice spacing of a similar or equal to 0.075 fm. We find good agreement with the expected Nc scaling and measure the coefficients of the leading and subleading terms in the large Nc expansion. From the subleading Nc corrections, we can also infer the Nf dependence, that we use to extract the value of the low-energy couplings for different values of Nf. We find agreement with previous determinations at Nc=3 and Nf=2,3 and also, our results support a strong paramagnetic suppression of the chiral condensate in moving from Nf=2 to Nf=3. |
| Address |
[Hernandez, P.; Romero-Lopez, F.] IFIC CSIC UVEG, Edificio Inst Invest,Apt 22085, Valencia 46071, Spain, Email: fernando.romero@uv.es |
| 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 |
1434-6044 |
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:000492031700002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4186 |
| Permanent link to this record |
