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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 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 (up)
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
Permanent link to this record
 
 
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 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 (up)
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
Permanent link to this record
 
 
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 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 (up) [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
Permanent link to this record
 
 
Author Bas i Beneito, A.; Gargalionis, J.; Herrero-Garcia, J.; Santamaria, A.; Schmidt, M.A.
Title An EFT approach to baryon number violation: lower limits on the new physics scale and correlations between nucleon decay modes Type Journal Article
Year 2024 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 004 - 37pp
Keywords Baryon/Lepton Number Violation; SMEFT; Specific BSM Phenomenology
Abstract Baryon number is an accidental symmetry of the Standard Model at the Lagrangian level. Its violation is arguably one of the most compelling phenomena predicted by physics beyond the Standard Model. Furthermore, there is a large experimental effort to search for it including the Hyper-K, DUNE, JUNO, and THEIA experiments. Therefore, an agnostic, model-independent, analysis of baryon number violation using the power of Effective Field Theory is very timely. In particular, in this work we study the contribution of dimension six and seven effective operators to |triangle(B – L)| = 0, 2 nucleon decays taking into account the effects of Renormalisation Group Evolution. We obtain lower limits on the energy scale of each operator and study the correlations between different decay modes. We find that for some operators the effect of running is very significant.
Address (up) [Bas i Beneito, Arnau; Gargalionis, John; Herrero-Garcia, Juan; Santamaria, Arcadi] Univ Valencia, Dept Fis Teor, Burjassot 46100, Spain, Email: arnau.bas@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:001262559200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6181
Permanent link to this record
 
 
Author Bas i Beneito, A.; Gargalionis, J.; Herrero-Garcia, J.; Schmidt, M.A.
Title Squeezing proton decay and neutrino masses: upper bounds on standard model extensions Type Journal Article
Year 2025 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 083 - 40pp
Keywords Baryon/Lepton Number Violation; SMEFT
Abstract Baryon and lepton number are excellent low-energy symmetries of the Standard Model (SM) that tightly constrain the form of its extensions. In this paper we investigate the possibility that these accidental symmetries are violated in the deep UV, in such a way that one multiplet necessary for their violation lives at an intermediate energy scale M above the electroweak scale. We write down the simplest effective operators containing each multiplet that may couple linearly to the SM at the renormalisable level and estimate the dominant contribution of the underlying UV model to the pertinent operators in the SMEFT: the dimension-5 Weinberg operator and the baryon-number-violating operators up to dimension 7. Our results are upper bounds on the scale M for each multiplet-operator pair, derived from neutrino-oscillation data as well as prospective nucleon-decay searches. We also analyse the possibility that both processes are simultaneously explained within a natural UV model. In addition, we advocate that our framework provides a convenient and digestible way of organising the space of UV models that violate these symmetries.
Address (up) [Bas i Beneito, Arnau; Gargalionis, John; Herrero-Garcia, Juan] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Spain, Email: arnau.bas@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 ISBN Medium
Area Expedition Conference
Notes WOS:001592048100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6889
Permanent link to this record
 
 
Author Bas i Beneito, A.; Herrero-Garcia, J.; Vatsyayan, D.
Title Multi-component dark sectors: symmetries, asymmetries and conversions Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 075 - 31pp
Keywords Models for Dark Matter; Particle Nature of Dark Matter
Abstract We study the relic abundance of several stable particles from a generic dark sector, including the possible presence of dark asymmetries. After discussing the different possibilities for stabilising multi-component dark matter, we analyse the final relic abundance of the symmetric and asymmetric dark matter components, paying special attention to the role of the unavoidable conversions between dark matter states. We find an exponential dependence of the asymmetries of the heavier components on annihilations and conversions. We conclude that having similar symmetric and asymmetric components is a natural outcome in many scenarios of multi-component dark matter. This has novel phenomenological implications, which we briefly discuss.
Address (up) [Bas I Beneito, Arnau] Univ Valencia, Dept Fis Teor, C Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: arnau.bas@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:000866484800002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5380
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 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 (up) [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
 
 
Author Berbig, M.; Herrero-Garcia, J.; Landini, G.
Title Dynamical origin of neutrino masses and dark matter from a new confining sector Type Journal Article
Year 2024 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 110 Issue 3 Pages 035011 - 13pp
Keywords
Abstract A dynamical mechanism, based on a confining non-Abelian dark symmetry, which generates Majorana masses for hyperchargeless fermions, is proposed. We apply it to the inverse seesaw scenario, which allows us to generate light neutrino masses from the interplay of TeV-scale pseudo-Dirac mass terms and a small explicit breaking of lepton number. A single generation of vectorlike dark quarks, transforming under a SU(3)D gauge symmetry, is coupled to a real singlet scalar, which serves as a portal between the dark quark condensate and three generations of heavy sterile neutrinos. Such a dark sector and the Standard Model (SM) are kept in thermal equilibrium with each other via sizable Yukawa couplings to the heavy neutrinos. In this framework, the lightest dark baryon, which has spin 3/2 and is stabilized at the renormalizable level by an accidental dark baryon number symmetry, can account for the observed relic density via thermal freeze-out from annihilations into the lightest dark mesons. These mesons, in turn, decay to heavy neutrinos, which produce SM final states upon decay. This model may be probed by next generation neutrino telescopes via neutrino lines produced from dark matter annihilations.
Address (up) [Berbig, Maximilian; Herrero-Garcia, Juan] Univ Valencia, Dept Fis Teor, Burjassot 46100, Spain, Email: berbig@ific.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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:001347981700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 6339
Permanent link to this record
 
 
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 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 (up) [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
Permanent link to this record
 
 
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 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 (up) [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
Permanent link to this record