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Author Fernandez-Martinez, E.; Gonzalez-Lopez, M.; Hernandez-Garcia, J.; Hostert, M.; Lopez-Pavon, J.
Title Effective portals to heavy neutral leptons Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal (up) J. High Energy Phys.
Volume 09 Issue 9 Pages 001 - 45pp
Keywords Neutrino Interactions; Non-Standard Neutrino Properties; Sterile or Heavy Neutrinos
Abstract The existence of right-handed neutrinos, or heavy neutral leptons (HNLs), is strongly motivated by the observation of neutrino masses and mixing. The mass of these new particles could lie below the electroweak scale, making them accessible to lowenergy laboratory experiments. Additional new physics at high energies can mediate new interactions between the Standard Model particles and HNLs, and is most conveniently parametrized by the neutrino Standard Model Effective Field Theory, or nu SMEFT for short. In this work, we consider the dimension six nu SMEFT operators involving one HNL field in the mass range of O(1) MeV < MN < O(100) GeV. By recasting existing experimental limits on the production and decay of new light particles, we constrain the Wilson coefficients and new physics scale of each operator as a function of the HNL mass.
Address [Fernandez-Martinez, Enrique; Gonzalez-Lopez, Manuel] Univ Autonoma Madrid, Inst Fis Teor, Campus Cantoblanco, Madrid 28049, Spain, Email: enrique.fernandez-martinez@uam.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:001067715500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5697
Permanent link to this record
 
 
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 (up) 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 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:001111979900002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5869
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Author Abdullahi, A.M. et al; Lopez-Pavon, J.
Title The present and future status of heavy neutral leptons Type Journal Article
Year 2023 Publication Journal of Physics G Abbreviated Journal (up) J. Phys. G
Volume 50 Issue 2 Pages 020501 - 100pp
Keywords Neutrinos; beyond the standard model; sterile neutrinos
Abstract The existence of nonzero neutrino masses points to the likely existence of multiple Standard Model neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as heavy neutral leptons (HNLs). In this white paper, we discuss the present experimental status of HNLs including colliders, beta decay, accelerators, as well as astrophysical and cosmological impacts. We discuss the importance of continuing to search for HNLs, and its potential impact on our understanding of key fundamental questions, and additionally we outline the future prospects for next-generation future experiments or upcoming accelerator run scenarios.
Address [Abdullahi, Asli M.; Plestid, Ryan] Fermilab Natl Accelerator Lab, Theoret Phys Dept, POB 500, Batavia, IL 60510 USA, Email: shoemaker@vt.edu
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 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000918351600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5486
Permanent link to this record
 
 
Author Hernandez, P.; Kekic, M.; Lopez-Pavon, J.
Title Low-scale seesaw models versus N-eff Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 89 Issue 7 Pages 073009 - 7pp
Keywords
Abstract We consider the contribution of the extra sterile states in generic low-scale seesaw models to extra radiation, parametrized by N-eff. We find that the value of Neff is roughly independent of the seesaw scale within a wide range. We explore the full parameter space in the case of two extra sterile states and find that these models are strongly constrained by cosmological data for any value of the seesaw scale below O(100 MeV).
Address [Hernandez, P.; Kekic, M.] IFIC CSIC UVEG, 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000334317200005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1754
Permanent link to this record
 
 
Author Hernandez, P.; Kekic, M.; Lopez-Pavon, J.
Title N_eff in low-scale seesaw models versus the lightest neutrino mass Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 90 Issue 6 Pages 065033 - 12pp
Keywords
Abstract We evaluate the contribution to N_eff of the extra sterile states in low-scale type I seesaw models (with three extra sterile states). We explore the full parameter space and find that at least two of the heavy states always reach thermalization in the early Universe, while the third one might not thermalize provided the lightest neutrino mass is below O(10(-3) eV). Constraints from cosmology therefore severely restrict the spectra of heavy states in the range 1 eV-100 MeV. The implications for neutrinoless double beta decay are also discussed.
Address [Hernandez, P.; Kekic, M.] Univ Valencia, IFIC CSIC, E-46071 Valencia, Spain, Email: m.pilar.hernandez@uv.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:000344108100004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2001
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Author Linster, M.; Lopez-Pavon, J.; Ziegler, R.
Title Neutrino observables from a U(2) flavor symmetry Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 103 Issue 1 Pages 015020 - 9pp
Keywords
Abstract We study the predictions for CP phases and absolute neutrino mass scale for broad classes of models with a U(2)-like flavor symmetry. For this purpose we consider the same special textures in neutrino and charged lepton mass matrices that are successful in the quark sector. While in the neutrino sector the U(2) structure enforces two texture zeros, the contribution of the charged lepton sector to the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix can be parametrized by two rotation angles. Restricting to the cases where at least one of these angles is small, we obtain three representative scenarios. In all scenarios we obtain a narrow prediction for the sum of neutrino masses in the range of 60-75 meV, possibly in the reach of upcoming galaxy survey experiments. All scenarios can be excluded if near-future experimental date provide evidence for either neutrinoless double-beta decay or inverted neutrino mass ordering.
Address [Linster, Matthias; Ziegler, Robert] Karlsruhe Inst Technol, Inst Theoret Teilchenphys, D-76131 Karlsruhe, Germany
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:000609014300006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4689
Permanent link to this record