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Author Hernandez, P.
Title CP violation in the neutrino sector: The new frontier Type Journal Article
Year 2012 Publication Comptes Rendus Physique Abbreviated Journal C. R. Phys.
Volume 13 Issue 2 Pages 186-192
Keywords Flavour physics; Neutrino physics; Matter-antimatter asymmetry
Abstract The discovery of neutrino masses has revealed a new flavour sector in the Standard Model. Just like the quark flavour sector, it contains a seed of CP violation, resulting in an asymmetric behaviour of matter and antimatter. It is argued that this new source of leptonic CP violation may be discovered in more precise neutrino oscillation experiments involving neutrino beams with energies in the GeV range that will be sent to distances of a few thousand kilometres.
Address [Hernandez, Pilar] Dpto Fis Teor UV, Valencia 46071, Spain, Email: m.pilar.hernandez@uv.es
Corporate Author Thesis
Publisher Elsevier France-Editions Scientifiques Medicales Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1631-0705 ISBN Medium
Area Expedition Conference
Notes WOS:000301037700015 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 934
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Author Agarwalla, S.K.; Hernandez, P.
Title Probing the neutrino mass hierarchy with Super-Kamiokande Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 086 - 14pp
Keywords Neutrino Physics; Beyond Standard Model
Abstract We show that for recently discovered large values of theta(13), a superbeam with an average neutrino energy of similar to 5 GeV, such as those being proposed at CERN, if pointing to Super-Kamiokande (L similar or equal to 8770 km), could reveal the neutrino mass hierarchy at 5 sigma in less than two years irrespective of the true hierarchy and CP phase. The measurement relies on the near resonant matter effect in the nu(mu) -> nu(e) oscillation channel, and can be done counting the total number of appearance events with just a neutrino beam.
Address [Agarwalla, Sanjib Kumar; Hernandez, Pilar] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Sanjib.Agarwalla@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000310851600047 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 1251
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Author Donini, A.; Hernandez, P.; Pena, C.; Romero-Lopez, F.
Title Nonleptonic kaon decays at large N-c Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 94 Issue 11 Pages 114511 - 6pp
Keywords
Abstract We study the scaling with the number of colors, N-c, of the weak amplitudes mediating kaon mixing and decay. We evaluate the amplitudes of the two relevant current-current operators on the lattice for N-c = 3-7. We conclude that the subleading 1/N-c corrections in B-k, are small, but those in the K -> pi pi amplitudes are large and fully anticoirelated in the I = 0, 2 isospin channels. We briefly comment on the implications for the Delta I = 1/2 rule.
Address [Donini, A.; Hernandez, P.; Romero-Lopez, F.] IFIC CSIC UVEG, Edificio Inst Invest,Apt 22085, E-46071 Valencia, Spain
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:000390275100007 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 2894
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Author Caputo, A.; Hernandez, P.; Rius, N.
Title Leptogenesis from oscillations and dark matter Type Journal Article
Year 2019 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 79 Issue 7 Pages 574 - 17pp
Keywords
Abstract An extension of the Standard Model with Majorana singlet fermions in the 1-100GeV range can explain the light neutrino masses and give rise to a baryon asymmetry at freeze-in of the heavy states, via their CP-violating oscillations. In this paper we consider extending this scenario to also explain dark matter. We find that a very weakly coupled B-L gauge boson, an invisible QCD axion model, and the singlet majoron model can simultaneously account for dark matter and the baryon asymmetry.
Address [Caputo, Andrea] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: andrea.caputo@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000475617900002 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 4090
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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
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 Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000492031700002 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 4186
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Author Donini, A.; Hernandez, P.; Pena, C.; Romero-Lopez, F.
Title Dissecting the Delta I=1/2 rule at large N-c Type Journal Article
Year 2020 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 80 Issue 7 Pages 638 - 12pp
Keywords
Abstract We study the scaling of kaon decay amplitudes with the number of colours, N-c, in a theory with four degenerate flavours, N-f = 4. In this scenario, two current-current operators, Q(+/-), mediate Delta S = 1 transitions, such as the two isospin amplitudes of non-leptonic kaon decays for K -> (pi pi)(I=0,2), A(0) and A(2.) In particular, we concentrate on the simpler K -> pi amplitudes, A(+/-), mediated by these two operators. A diagrammatic analysis of the large-N-c scaling of these observables is presented, which demonstrates the anticorrelation of the leading O(1/N-c) and O(N-f/N-c(2)) corrections in both amplitudes. Using our new N-f = 4 and previous quenched data, we confirm this expectation and show that these corrections are naturally large and may be at the origin of the Delta I = 1/2 rule. The evidence for the latter is indirect, based on the matching of the amplitudes to their prediction in Chiral Perturbation Theory, from which the LO low-energy couplings of the chiral weak Hamiltonian, g(+/-), can be determined. A NLO estimate of the K -> (pi pi)(I=0,2) isospin amplitudes can then be derived, which is in good agreement with the experimental value.
Address [Donini, Andrea; Hernandez, Pilar; Romero-Lopez, Fernando] IFIC CSIC UVEG, Edificio Inst Invest,Apt 22085, Valencia 46071, Spain, Email: fernando.romero@uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000552393200003 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 4480
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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
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 Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000617515000003 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 4718
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Author Albandea, D.; Hernandez, P.; Ramos, A.; Romero-Lopez, F.
Title Topological sampling through windings Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 10 Pages 873 - 12pp
Keywords
Abstract We propose a modification of the Hybrid Monte Carlo (HMC) algorithm that overcomes the topological freezing of a two-dimensional U(1) gauge theory with and without fermion content. This algorithm includes reversible jumps between topological sectors – winding steps – combined with standard HMC steps. The full algorithm is referred to as winding HMC (wHMC), and it shows an improved behaviour of the autocorrelation time towards the continuum limit. We find excellent agreement between the wHMC estimates of the plaquette and topological susceptibility and the analytical predictions in the U(1) pure gauge theory, which are known even at finite beta. We also study the expectation values in fixed topological sectors using both HMC and wHMC, with and without fermions. Even when topology is frozen in HMC – leading to significant deviations in topological as well as non-topological quantities – the two algorithms agree on the fixed-topology averages. Finally, we briefly compare the wHMC algorithm results to those obtained with master-field simulations of size L similar to 8 x 10(3).
Address [Albandea, David; Hernandez, Pilar; Ramos, Alberto; Romero-Lopez, Fernando] UVEG, CSIC, IFIC, Edificio Inst Invest,Apt 22085, Valencia 46071, Spain, Email: David.Albandea@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000703880600001 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 4979
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Author Coloma, P.; Hernandez, P.; Urrea, S.
Title New bounds on axion-like particles from MicroBooNE Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 025 - 25pp
Keywords Axions and ALPs; Kaons
Abstract Neutrino experiments lie at the edge of the intensity frontier and therefore can be exploited to search for new light particles weakly coupled to the visible sector. In this work we derive new constraints on axion-like particles (ALPs) using data from the MicroBooNE experiment, from a search for e(+)e(-) pairs pointing in the direction of the NuMI absorber. In particular, we consider the addition of higher-dimensional effective operators coupling the ALP to the electroweak gauge bosons. These would induce K -> pi a from kaon decay at rest in the NuMI absorber, as well as ALP decays into pairs of leptons or photons. We discuss in detail and compare various results obtained for the decay width K -> pi a in previous literature. For the operator involving the Higgs, MicroBooNE already sets competitive bounds (comparable to those of NA62) for ALP masses between 100 and 200 MeV. We also compute the expected sensitivities from the full NuMI dataset recorded at MicroBooNE. Our results show that a search for a -> gamma gamma signal may be able to improve over current constraints from beam-dump experiments on the operator involving the ALP coupling to the W.
Address [Coloma, Pilar] Univ Autonoma Madrid, Inst Fis Teor UAM CSIC, Calle Nicolas Cabrera 1315, E-28049 Madrid, Spain, Email: pilar.coloma@ift.csic.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000836240700003 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 5323
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Author Hernandez, P.; Lopez-Pavon, J.; Rius, N.; Sandner, S.
Title Bounds on right-handed neutrino parameters from observable leptogenesis Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue 12 Pages 012 - 58pp
Keywords Baryo-and Leptogenesis; Early Universe Particle Physics; Sterile or Heavy Neutrinos
Abstract We revisit the generation of a matter-antimatter asymmetry in the minimal extension of the Standard Model with two singlet heavy neutral leptons (HNL) that can explain neutrino masses. We derive an accurate analytical approximation to the solution of the complete linearized set of kinetic equations, which exposes the non-trivial parameter dependencies in the form of parameterization-independent CP invariants. The identification of various washout regimes relevant in different regions of parameter space sheds light on the relevance of the mass corrections in the interaction rates and clarifies the correlations of baryogenesis with other observables. In particular, by requiring that the measured baryon asymmetry is reproduced, we derive robust upper or lower bounds on the HNL mixings depending on their masses, and constraints on their flavour structure, as well as on the CP-violating phases of the PMNS mixing matrix, and the amplitude of neutrinoless double-beta decay. We also find certain correlations between low and high scale CP phases. Especially emphasizing the testable part of the parameter space we demonstrate that our findings are in very good agreement with numerical results. The methods developed in this work can help in exploring more complex scenarios.
Address [Hernandez, P.] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: m.pilar.hernandez@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000914640400003 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 5467
Permanent link to this record