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Author Giarnetti, A.; Herrero-Garcia, J.; Marciano, S.; Meloni, D.; Vatsyayan, D.
Title Neutrino masses from new seesaw models: low-scale variants and phenomenological implications Type Journal Article
Year 2024 Publication (up) European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 84 Issue 8 Pages 803 - 19pp
Keywords
Abstract With just the Standard Model Higgs doublet, there are only three types of seesaw models that generate light Majorana neutrino masses at tree level after electroweak spontaneous symmetry breaking. However, if there exist additional TeV scalars acquiring vacuum expectation values, coupled with heavier fermionic multiplets, several new seesaw models become possible. These new seesaws are the primary focus of this study and correspond to the tree-level ultraviolet completions of the effective operators studied in a companion publication. We are interested in the genuine cases, in which the standard seesaw contributions are absent. In addition to the tree-level generation of neutrino masses, we also consider the one-loop contributions. Furthermore, we construct low-energy versions that exhibit a very rich phenomenology. Specifically, we scrutinise the generation of dimension-6 operators and explore their implications, including non-unitarity of the leptonic mixing matrix, non-universal Z-boson interactions, and lepton flavor violation. Finally, we provide (Generalised) Scotogenic-like variants that incorporate viable dark matter candidates.
Address [Giarnetti, Alessio; Marciano, Simone; Meloni, Davide] Univ Roma Tre, Dipartimento Matemat & Fis, Via Vasca Navale 84, I-00146 Rome, Italy, Email: simone.marciano@uniroma3.it
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:001289661800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6229
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Author Cai, Y.; Herrero-Garcia, J.; Schmidt, M.A.; Vicente, A.; Volkas, R.R.
Title From the Trees to the Forest: A Review of Radiative Neutrino Mass Models Type Journal Article
Year 2017 Publication (up) Frontiers in Physics Abbreviated Journal Front. Physics
Volume 5 Issue Pages 63 - 56pp
Keywords neutrino masses; lepton flavor violation; lepton number violation; beyond the standard model; effective field theory; model building; LHC; dark matter
Abstract A plausible explanation for the lightness of neutrino masses is that neutrinos are massless at tree level, with their mass (typically Majorana) being generated radiatively at one or more loops. The new couplings, together with the suppression coming from the loop factors, imply that the new degrees of freedom cannot be too heavy (they are typically at the TeV scale). Therefore, in these models there are no large mass hierarchies and they can be tested using different searches, making their detailed phenomenological study very appealing. In particular, the new particles can be searched for at colliders and generically induce signals in lepton-flavor and lepton-number violating processes (in the case of Majorana neutrinos), which are not independent from reproducing correctly the neutrino masses and mixings. The main focus of the review is on Majorana neutrinos. We order the allowed theory space from three different perspectives: (i) using an effective operator approach to lepton number violation, (ii) by the number of loops at which the Weinberg operator is generated, (iii) within a given loop order, by the possible irreducible topologies. We also discuss in more detail some popular radiative models which involve qualitatively different features, revisiting their most important phenomenological implications. Finally, we list some promising avenues to pursue.
Address [Cai, Yi] Sun Yat Sen Univ, Sch Phys, Guangzhou, Guangdong, Peoples R China, Email: juan.herrero-garcia@coepp.org.au;
Corporate Author Thesis
Publisher Frontiers Research Foundation Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-424x ISBN Medium
Area Expedition Conference
Notes WOS:000416908800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3393
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Author Herrero-Garcia, J.; Schwetz, T.; Zupan, J.
Title On the annual modulation signal in dark matter direct detection Type Journal Article
Year 2012 Publication (up) Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages 005 - 28pp
Keywords dark matter theory; dark matter experiments; dark matter detectors
Abstract We derive constraints on the annual modulation signal in Dark Matter (DM) direct detection experiments in terms of the unmodulated event rate. A general bound independent of the details of the DM distribution follows from the assumption that the motion of the earth around the sun is the only source of time variation. The bound is valid for a very general class of particle physics models and also holds in the presence of an unknown unmodulated background. More stringent bounds are obtained, if modest assumptions on symmetry properties of the DM halo are adopted. We illustrate the bounds by applying them to the annual modulation signals reported by the DAMA and CoGeNT experiments in the framework of spin-independent elastic scattering. While the DAMA signal satisfies our bounds, severe restrictions on the DM mass can be set for CoGeNT.
Address [Herrero-Garcia, Juan; Schwetz, Thomas] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany, Email: juan.a.herrero@uv.es;
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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000302949600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1000
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Author Bozorgnia, N.; Herrero-Garcia, J.; Schwetz, T.; Zupan, J.
Title Halo-independent methods for inelastic dark matter scattering Type Journal Article
Year 2013 Publication (up) Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 049 - 15pp
Keywords dark matter theory; dark matter experiments
Abstract We present halo-independent methods to analyze the results of dark matter direct detection experiments assuming inelastic scattering. We focus on the annual modulation signal reported by DAMA/LIBRA and present three different halo-independent tests. First, we compare it to the upper limit on the unmodulated rate from XENON100 using (a) the trivial requirement that the amplitude of the annual modulation has to be smaller than the bound on the unmodulated rate, and (b) a bound on the annual modulation amplitude based on an expansion in the Earth's velocity. The third test uses the special predictions of the signal shape for inelastic scattering and allows for an internal consistency check of the data without referring to any astrophysics. We conclude that a strong conflict between DAMA/LIBRA and XENON100 in the framework of spin-independent inelastic scattering can be established independently of the local properties of the dark matter halo.
Address [Bozorgnia, Nassim; Schwetz, Thomas] Max Planck Inst Kernphys, D-69117 Heidelberg, Germany, Email: bozorgnia@mpi-hd.mpg.de;
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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000322582000050 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1530
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Author Herrero-Garcia, J.; Patrick, R.; Scaffidi, A.
Title A semi-supervised approach to dark matter searches in direct detection data with machine learning Type Journal Article
Year 2022 Publication (up) Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue Pages 039 - 19pp
Keywords
Abstract The dark matter sector remains completely unknown. It is therefore crucial to keep an open mind regarding its nature and possible interactions. Focusing on the case of Weakly Interacting Massive Particles, in this work we make this general philosophy more concrete by applying modern machine learning techniques to dark matter direct detection. We do this by encoding and decoding the graphical representation of background events in the XENONnT experiment with a convolutional variational autoencoder. We describe a methodology that utilizes the `anomaly score' derived from the reconstruction loss of the convolutional variational autoencoder as well as a pre-trained standard convolutional neural network, in a semi-supervised fashion. Indeed, we observe that optimum results are obtained only when both unsupervised and supervised anomaly scores are considered together. A data set that has a higher proportion of anomaly score is deemed anomalous and deserves further investigation. Contrary to classical analyses, in principle all information about the events is used, preventing unnecessary information loss. Lastly, we demonstrate the reach of learning-focused anomaly detection in this context by comparing results with classical inference, observing that, if tuned properly, these techniques have the potential to outperform likelihood-based methods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5495
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Author Aparici, A.; Herrero-Garcia, J.; Rius, N.; Santamaria, A.
Title Neutrino masses from new generations Type Journal Article
Year 2011 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 122
Keywords
Abstract We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, mu-e conversion in nuclei and μ-> e gamma experiments. We also discuss the detection prospects at LHC.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language 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:000293741500058 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 759
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Author Aparici, A.; Herrero-Garcia, J.; Rius, N.; Santamaria, A.
Title On the nature of the fourth generation neutrino and its implications Type Journal Article
Year 2012 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 030 - 31pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We consider the neutrino sector of a Standard Model with four generations. While the three light neutrinos can obtain their masses from a variety of mechanisms with or without new neutral fermions, fourth-generation neutrinos need at least one new relatively light right-handed neutrino. If lepton number is not conserved this neutrino must have a Majorana mass term whose size depends on the underlying mechanism for lepton number violation. Majorana masses for the fourth-generation neutrinos induce relative large two-loop contributions to the light neutrino masses which could be even larger than the cosmological bounds. This sets strong limits on the mass parameters and mixings of the fourth-generation neutrinos.
Address [Aparici, Alberto] Univ Valencia, CSIC, Dept Fis Teor, Valencia 46071, Spain, Email: alberto.aparici@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:000307298400030 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1157
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Author Herrero-Garcia, J.; Rius, N.; Santamaria, A.
Title Higgs lepton flavour violation: UV completions and connection to neutrino masses Type Journal Article
Year 2016 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 084 - 45pp
Keywords Beyond Standard Model; Higgs Physics; Neutrino Physics
Abstract We study lepton violating Higgs (HLFV) decays, first from the effective field theory (EFT) point of view, and then analysing the different high-energy realizations of the operators of the EFT, highlighting the most promising models. We argue why two Higgs doublet models can have a BR(h -> tau mu) similar to 0:01, and why this rate is suppressed in all other realizations including vector-like leptons. We further discuss HLFV in the context of neutrino mass models: in most cases it is generated at one loop giving always BR (h -> tau mu) < 10(-4) and typically much less, which is beyond experimental reach. However, both the Zee model and extended left-right symmetric models contain extra SU(2) doublets coupled to leptons and could in principle account for the observed excess, with interesting connections between HLFV and neutrino parameters.
Address [Herrero-Garcia, Juan] KTH Royal Inst Technol, AlbaNova Univ Ctr, Sch Engn Sci, Dept Theoret Phys, S-10691 Stockholm, Sweden, Email: juhg@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:000387843300004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2862
Permanent link to this record
 

 
Author Felkl, T.; Herrero-Garcia, J.; Schmidt, M.A.
Title The singly-charged scalar singlet as the origin of neutrino masses Type Journal Article
Year 2021 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 122 - 39pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We consider the generation of neutrino masses via a singly-charged scalar singlet. Under general assumptions we identify two distinct structures for the neutrino mass matrix. This yields a constraint for the antisymmetric Yukawa coupling of the singly-charged scalar singlet to two left-handed lepton doublets, irrespective of how the breaking of lepton-number conservation is achieved. The constraint disfavours large hierarchies among the Yukawa couplings. We study the implications for the phenomenology of lepton-flavour universality, measurements of the W-boson mass, flavour violation in the charged-lepton sector and decays of the singly-charged scalar singlet. We also discuss the parameter space that can address the Cabibbo Angle Anomaly.
Address [Felkl, Tobias; Schmidt, Michael A.] Univ New South Wales, Sch Phys, Sydney Consortium Particle Phys & Cosmol, Sydney, NSW 2052, Australia, Email: t.felkl@unsw.edu.au;
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:000656967200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4851
Permanent link to this record
 

 
Author Beniwal, A.; Herrero-Garcia, J.; Leerdam, N.; White, M.; Williams, A.G.
Title The ScotoSinglet Model: a scalar singlet extension of the Scotogenic Model Type Journal Article
Year 2021 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 136 - 34pp
Keywords Beyond Standard Model; Higgs Physics; Neutrino Physics
Abstract The Scotogenic Model is one of the most minimal models to account for both neutrino masses and dark matter (DM). In this model, neutrino masses are generated at the one-loop level, and in principle, both the lightest fermion singlet and the lightest neutral component of the scalar doublet can be viable DM candidates. However, the correct DM relic abundance can only be obtained in somewhat small regions of the parameter space, as there are strong constraints stemming from lepton flavour violation, neutrino masses, electroweak precision tests and direct detection. For the case of scalar DM, a sufficiently large lepton-number-violating coupling is required, whereas for fermionic DM, coannihilations are typically necessary. In this work, we study how the new scalar singlet modifies the phenomenology of the Scotogenic Model, particularly in the case of scalar DM. We find that the new singlet modifies both the phenomenology of neutrino masses and scalar DM, and opens up a large portion of the parameter space of the original model.
Address [Beniwal, Ankit] Catholic Univ Louvain, Ctr Cosmol Particle Phys & Phenomenol CP3, B-1348 Louvain La Neuve, Belgium, Email: ankit.beniwal@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 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000668611300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4881
Permanent link to this record