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Author Drewes, M.; Klaric, J.; Lopez-Pavon, J.
Title New benchmark models for heavy neutral lepton searches Type Journal Article
Year 2022 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 82 Issue 12 Pages 1176 - 11pp
Keywords
Abstract The sensitivity of direct searches for heavy neutral leptons (HNLs) in accelerator-based experiments depends strongly on the particles properties. Commonly used benchmark scenarios are important to ensure comparability and consistency between experimental searches, re-interpretations, and sensitivity studies for different facilities. In models where the HNLs are primarily produced and decay through the weak interaction, benchmarks are in particular defined by fixing the relative strengths of their mixing with SM neutrinos of different flavours, and the interpretation of experimental data is known to strongly depend on those ratios. The commonly used benchmarks in which a single HNL flavour exclusively interacts with one Standard Model generation do not reflect what is found in realistic neutrino mass models. We identify two additional benchmarks for accelerator-based direct HNL searches, which we primarily select based on the requirement to provide a better approximation for the phenomenology of realistic neutrino mass models in view of present and future neutrino oscillation data.
Address [Drewes, M.; Klaric, J.] Catholic Univ Louvain, Ctr Cosmol Particle Phys & Phenomenol, B-1348 Louvain La Neuve, Belgium, Email: marco.drewes@uclouvain.be;
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:000906204200001 Approved no
Is ISI yes International Collaboration yes
Call Number (down) IFIC @ pastor @ Serial 5446
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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 no
Call Number (down) IFIC @ pastor @ Serial 5467
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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 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 (down) IFIC @ pastor @ Serial 5486
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Author Bertolez-Martinez, T.; Arguelles, C.; Esteban, I.; Lopez-Pavon, J.; Martinez-Soler, I.; Salvado, J.
Title IceCube and the origin of ANITA-IV events Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 005 - 24pp
Keywords Cosmic Rays; Specific BSM Phenomenology
Abstract Recently, the ANITA collaboration announced the detection of new, unsettling upgoing Ultra-High-Energy (UHE) events. Understanding their origin is pressing to ensure success of the incoming UHE neutrino program. In this work, we study their internal consistency and the implications of the lack of similar events in IceCube. We introduce a generic, simple parametrization to study the compatibility between these two observatories in Standard Model-like and Beyond Standard Model scenarios: an incoming flux of particles that interact with Earth nucleons with cross section sigma, producing particle showers along with long-lived particles that decay with lifetime iota and generate a shower that explains ANITA observations. We find that the ANITA angular distribution imposes significant constraints, and when including null observations from IceCube only iota similar to 10(-3)-10(-2) s and sigma similar to 10(-33) -10(-32) cm(2) can explain the data. This hypothesis is testable with future IceCube data. Finally, we discuss a specific model that can realize this scenario. Our analysis highlights the importance of simultaneous observations by high-energy optical neutrino telescopes and new UHE radio detectors to uncover cosmogenic neutrinos or discover new physics.
Address [Bertolez-Martinez, Toni; Salvado, Jordi] Univ Barcelona, Dept Fis Quant & Astrofis, Diagonal 647, E-08028 Barcelona, Spain, Email: antoni.bertolez@fqa.ub.edu;
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:001021483800005 Approved no
Is ISI yes International Collaboration yes
Call Number (down) IFIC @ pastor @ Serial 5589
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Author Blennow, M.; Fernandez-Martinez, E.; Hernandez-Garcia, J.; Lopez-Pavon, J.; Marcano, X.; Naredo-Tuero, D.
Title Bounds on lepton non-unitarity and heavy neutrino mixing Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 030 - 41pp
Keywords Electroweak Precision Physics; Neutrino Mixing; Sterile or Heavy Neutrinos
Abstract We present an updated and improved global fit analysis of current flavour and electroweak precision observables to derive bounds on unitarity deviations of the leptonic mixing matrix and on the mixing of heavy neutrinos with the active flavours. This new analysis is motivated by new and updated experimental results on key observables such as V-ud, the invisible decay width of the Z boson and the W boson mass. It also improves upon previous studies by considering the full correlations among the different observables and explicitly calibrating the test statistic, which may present significant deviations from a & chi;(2) distribution. The results are provided for three different Type-I seesaw scenarios: the minimal scenario with only two additional right-handed neutrinos, the next to minimal one with three extra neutrinos, and the most general one with an arbitrary number of heavy neutrinos that we parametrise via a generic deviation from a unitary leptonic mixing matrix. Additionally, we also analyze the case of generic deviations from unitarity of the leptonic mixing matrix, not necessarily induced by the presence of additional neutrinos. This last case relaxes some correlations among the parameters and is able to provide a better fit to the data. Nevertheless, inducing only leptonic unitarity deviations avoiding both the correlations implied by the right-handed neutrino extension as well as more strongly constrained operators is challenging and would imply significantly more complex UV completions.
Address [Blennow, Mattias] KTH Royal Inst Technol, AlbaNova Univ Ctr, Sch Engn Sci, Dept Phys, Roslagstullsbacken 21, S-10691 Stockholm, Sweden, Email: emb@kth.se;
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:001044930400003 Approved no
Is ISI yes International Collaboration yes
Call Number (down) IFIC @ pastor @ Serial 5607
Permanent link to this record