arXiv subjects

D. V. Forero

Publications and source records attributed to D. V. Forero.

18 recordsLinked to original sources

arXiv2025

Higgs-like Resonances and Massive Neutrinos in a 3-3-1 Model

Recent experimental results have reported mild deviations from Standard Model predictions in processes involving two photons in the final state, suggesting the possible presence of high-mass scalar resonances at the few-hundred-GeV scale. We investigate these anomalies within the framework of 3-3-1 models, a well-motivated class of extensions of the Standard Model. Focusing on the most relevant regions of parameter space, we determine the preferred scalar mass ranges and present the results in terms of probability density functions. We implement the 3-3-1 model with right-handed neutrinos, which can be considered as a benchmark within this class of models, in the SARAH package. The scalar sector is constructed from the most general potential involving three Higgs triplets and one scalar sextet, consistent with the required symmetries for a realistic model. The neutrino sector is also analyzed in some detail, where left- and right-handed neutrinos reside in the same leptonic multiplet. Neutrino masses are generated via the Type-I seesaw mechanism, and the Yukawa couplings were constrained employing the Casas-Ibarra parametrization. Finally, we discuss the constraints arising from flavor-changing neutral currents and electroweak precision data.

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arXiv2023

Five texture zeros in the lepton sector and neutrino oscillations at DUNE

In this work, we have assumed special structures for the charged and neutral mass matrices in the lepton sector, inspired by structures for the up and down quark mass matrices that result by assuming a certain number of symmetrical zeros in their entries named texture zeros. A prediction of the lepton mixing matrix results from the rotation matrices that diagonalize the mass matrices in the neutral and charged lepton sectors. The use of texture zeros reduces the number of spurious parameters to the minimal ones needed to explain observations i.e. charged lepton masses and neutrino oscillation parameters. Specifically, we have considered the case of five texture zeros and we have confronted the resulting lepton mixing matrices with current measurements in the neutrino sector. Finally, sensitivities to the independent parameters in the mixing predicted by the nonequivalent forms were studied using simulated events at the DUNE neutrino oscillation experiment. We have found that DUNE is sensitive to nonzero CP violation allowed in the models.

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arXiv2022

Snowmass White Paper: Beyond the Standard Model effects on Neutrino Flavor

Neutrinos are one of the most promising messengers for signals of new physics Beyond the Standard Model (BSM). On the theoretical side, their elusive nature, combined with their unknown mass mechanism, seems to indicate that the neutrino sector is indeed opening a window to new physics. On the experimental side, several long-standing anomalies have been reported in the past decades, providing a strong motivation to thoroughly test the standard three-neutrino oscillation paradigm. In this Snowmass21 white paper, we explore the potential of current and future neutrino experiments to explore BSM effects on neutrino flavor during the next decade.

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arXiv2022

Large Extra Dimensions and neutrino experiments

The existence of Large Extra Dimensions can be probed in various neutrino experiments. We analyze several neutrino data sets in a model with a dominant large extra dimension. We show that the Gallium anomaly can be explained with neutrino oscillations induced by the large extra dimension, but the region of parameter space which is preferred by the Gallium anomaly is in tension with the bounds from reactor rate data, as well as the data of Daya Bay and MINOS. We also present bounds obtained from the analysis of the KATRIN data. We show, that current experiments can put strong bounds on the size $R_{\text{ED}}$ of the extra dimension: $R_{\text{ED}} < 0.20~μ\text{m}$ and $R_{\text{ED}} < 0.10~μ\text{m}$ at 90\% C.L. for normal and inverted ordering of the standard neutrino masses, respectively.

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arXiv2022

Short-baseline oscillation scenarios at JUNO and TAO

We study the sensitivity of JUNO and TAO to the oscillations induced by two well-motivated scenarios beyond the standard model: Large Extra Dimensions (LED) and light sterile neutrinos in the context of 3+1 neutrino mixing. We find that JUNO+TAO can set competitive bounds on the parameter space of each scenario. In particular, we find that JUNO+TAO can be competitive with MINOS, DUNE or KATRIN in the context of LED. If LED are present in nature, we show that the parameters could be measured with a similar precision as the standard oscillation parameters. We also show that JUNO+TAO can test nearly all of the parameter space preferred by Gallium experiments in the context of 3+1 mixing. Finally, we discuss the possibility to distinguish the two scenarios from each other.

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arXiv2022

White Paper on Light Sterile Neutrino Searches and Related Phenomenology

This white paper provides a comprehensive review of our present understanding of experimental neutrino anomalies that remain unresolved, charting the progress achieved over the last decade at the experimental and phenomenological level, and sets the stage for future programmatic prospects in addressing those anomalies. It is purposed to serve as a guiding and motivational "encyclopedic" reference, with emphasis on needs and options for future exploration that may lead to the ultimate resolution of the anomalies. We see the main experimental, analysis, and theory-driven thrusts that will be essential to achieving this goal being: 1) Cover all anomaly sectors -- given the unresolved nature of all four canonical anomalies, it is imperative to support all pillars of a diverse experimental portfolio, source, reactor, decay-at-rest, decay-in-flight, and other methods/sources, to provide complementary probes of and increased precision for new physics explanations; 2) Pursue diverse signatures -- it is imperative that experiments make design and analysis choices that maximize sensitivity to as broad an array of these potential new physics signatures as possible; 3) Deepen theoretical engagement -- priority in the theory community should be placed on development of standard and beyond standard models relevant to all four short-baseline anomalies and the development of tools for efficient tests of these models with existing and future experimental datasets; 4) Openly share data -- Fluid communication between the experimental and theory communities will be required, which implies that both experimental data releases and theoretical calculations should be publicly available; and 5) Apply robust analysis techniques -- Appropriate statistical treatment is crucial to assess the compatibility of data sets within the context of any given model.

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arXiv2021

Non-unitary neutrino mixing in short and long-baseline experiments

Non-unitary neutrino mixing in the light neutrino sector is a direct consequence of type-I seesaw neutrino mass models. In these models, light neutrino mixing is described by a sub-matrix of the full lepton mixing matrix and, then, it is not unitary in general. In consequence, neutrino oscillations are characterized by additional parameters, including new sources of CP violation. Here we perform a combined analysis of short and long-baseline neutrino oscillation data in this extended mixing scenario. We did not find a significant deviation from unitary mixing, and the complementary data sets have been used to constrain the non-unitarity parameters. We have also found that the T2K and NOvA tension in the determination of the Dirac CP-phase is not alleviated in the context of non-unitary neutrino mixing.

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arXiv2021

2020 Global reassessment of the neutrino oscillation picture

We present an updated global fit of neutrino oscillation data in the simplest three-neutrino framework. In the present study we include up-to-date analyses from a number of experiments. Concerning the atmospheric and solar sectors, we give updated analyses of DeepCore and SNO data, respectively. We have also included the latest electron antineutrino data collected by the Daya Bay and RENO reactor experiments, and the long-baseline T2K and NO$ν$A measurements. These new analyses result in more accurate measurements of $θ_{13}$, $θ_{12}$, $Δm_{21}^2$ and $|Δm_{31}^2|$. The best fit value for the atmospheric angle $θ_{23}$ lies in the second octant, but first octant solutions remain allowed at $\sim2.4σ$. Regarding CP violation measurements, the preferred value of $δ$ we obtain is 1.08$π$ (1.58$π$) for normal (inverted) neutrino mass ordering. The global analysis prefers normal neutrino mass ordering with 2.5$σ$. This preference is milder than the one found in previous global analyses. The new results should be regarded as robust due to the agreement found between our Bayesian and frequentist approaches. Taking into account only oscillation data, there is a weak/moderate preference for the normal neutrino mass ordering of $2.00σ$. While adding neutrinoless double beta decay from the latest Gerda, CUORE and KamLAND-Zen results barely modifies this picture, cosmological measurements raise the preference to $2.68σ$ within a conservative approach. A more aggressive data set combination of cosmological observations leads to a similar preference, namely $2.70σ$. This very same cosmological data set provides $2σ$ upper limits on the total neutrino mass corresponding to $\sumν<0.12$ ($0.15$)~eV for normal (inverted) neutrino mass ordering.

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arXiv2019

Quantum Decoherence Effects in Neutrino Oscillations at DUNE

In this work we analyze quantum decoherence in neutrino oscillations considering the Open Quantum System framework and oscillations through matter for three neutrino families. Taking DUNE as a case study we performed sensitivity analyses for two neutrino flux configurations finding limits for the decoherence parameters. We also offer a physical interpretation for a new peak which arises at the $ν_{e}$ appearance probability with decoherence. The best sensitivity regions found for the decoherence parameters are $Γ_{21}\le 1.2\times10^{-23}\,\text{GeV}$ and $Γ_{32}\le 7.7\times10^{-25}\,\text{GeV}$ at $90\%$ C. L.

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arXiv2018

A Short Travel for Neutrinos in Large Extra Dimensions

Neutrino oscillations successfully explain the flavor transitions observed in neutrinos produced in natural sources like the center of the sun and the earth atmosphere, and also from man-made sources like reactors and accelerators. These oscillations are driven by two mass-squared differences, solar and atmospheric, at the sub-eV scale. However, longstanding anomalies at short-baselines might imply the existence of new oscillation frequencies at the eV-scale and the possibility of this sterile state(s) to mix with the three active neutrinos. One of the many future neutrino programs that are expected to provide a final word on this issue is the Short-Baseline Neutrino Program (SBN) at FERMILAB. In this letter, we consider a specific model of Large Extra Dimensions (LED) which provides interesting signatures of oscillation of extra sterile states. We started re-creating sensitivity analyses for sterile neutrinos in the 3+1 scenario, previously done by the SBN collaboration, by simulating neutrino events in the three SBN detectors from both muon neutrino disappearance and electron neutrino appearance. Then, we implemented neutrino oscillations as predicted in the LED model and also we have performed sensitivity analysis to the LED parameters. Finally, we studied the SBN power of discriminating between the two models, the 3+1 and the LED. We have found that SBN is sensitive to the oscillations predicted in the LED model and have the potential to constrain the LED parameter space better than any other oscillation experiment, for $m_{1}^D<0.1\,\text{eV}$. In case SBN observes a departure from the three active neutrino framework, it also has the power of discriminating between sterile oscillations predicted in the 3+1 framework and the LED ones.

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arXiv2018

Status of neutrino oscillations 2018: first hint for normal mass ordering and improved CP sensitivity

We present a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture, including new data which appeared since our previous analysis~\cite{Forero:2014bxa}. In this update we include new long-baseline neutrino data involving the antineutrino channel in T2K, as well as new data in the neutrino channel, data from NO$ν$A, as well as new reactor data, such as the Daya Bay 1230 days electron antineutrino disappearance spectrum data and the 1500 live days prompt spectrum from RENO, as well as new Double Chooz data. We also include atmospheric neutrino data from the IceCube DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we also update our solar oscillation analysis by including the 2055-day day/night spectrum from the fourth phase of the Super-Kamiokande experiment. With the new data we find a preference for the atmospheric angle in the upper octant for both neutrino mass orderings, with maximal mixing allowed at $Δχ^2 = 1.6 \, (3.2)$ for normal (inverted) ordering. We also obtain a strong preference for values of the CP phase $δ$ in the range $[π,2π]$, excluding values close to $π/2$ at more than 4$σ$. More remarkably, our global analysis shows for the first time hints in favour of the normal mass ordering over the inverted one at more than 3$σ$. We discuss in detail the origin of the mass ordering, CP violation and octant sensitivities, analyzing the interplay among the different neutrino data samples.

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arXiv2017

Probing CP violation with non-unitary mixing in long-baseline neutrino oscillation experiments: DUNE as a case study

When neutrino masses arise from the exchange of neutral heavy leptons, as in most seesaw schemes, the effective lepton mixing matrix $N$ describing neutrino propagation is non-unitary, hence neutrinos are not exactly orthonormal. New CP violation phases appear in $N$ that could be confused with the standard phase $δ_{\text{CP}}$ characterizing the three neutrino paradigm. We study the potential of the long-baseline neutrino experiment DUNE in probing CP violation induced by the standard CP phase in the presence of non-unitarity. In order to accomplish this we develop our previous formalism, so as to take into account the neutrino interactions with the medium, important in long baseline experiments such as DUNE. We find that the expected CP sensitivity of DUNE is somewhat degraded with respect to that characterizing the standard unitary case. However the effect is weaker than might have been expected thanks mainly to the wide neutrino beam. We also investigate the sensitivity of DUNE to the parameters characterizing non-unitarity. In this case we find that there is no improvement expected with respect to the current situation, unless the near detector setup is revamped.

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arXiv2016

On the description of non-unitary neutrino mixing

Neutrino oscillations are well established and the relevant parameters determined with good precision, except for the CP phase, in terms of a unitary lepton mixing matrix. Seesaw extensions of the Standard Model predict unitarity deviations due to the admixture of heavy isosinglet neutrinos. We provide a complete description of the unitarity and universality deviations in the light neutrino sector. Neutrino oscillation experiments involving electron or muon neutrinos and anti-neutrinos are fully described in terms of just three new real parameters and a new CP phase, in addition to the ones describing oscillations with unitary mixing. Using this formalism we describe the implications of non-unitarity for neutrino oscillations and summarize the model-independent constraints on heavy neutrino couplings that arise from current experiments.

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arXiv2015

Constraining right-handed neutrinos

Several models of neutrino masses predict the existence of neutral heavy leptons. Here, we review current constraints on heavy neutrinos and apply a new formalism separating new physics from Standard Model. We discuss also the indirect effect of extra heavy neutrinos in oscillation experiments.

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arXiv2014

Neutrino oscillations refitted

Here we update our previous global fit of neutrino oscillations by including the recent results which have appeared since the Neutrino-2012 conference. These include the measurements of reactor anti-neutrino disappearance reported by Daya Bay and RENO, together with latest T2K and MINOS data including both disappearance and appearance channels. We also include the revised results from the third solar phase of Super-Kamiokande, SK-III, as well as new solar results from the fourth phase of Super-Kamiokande, SK-IV. We find that the preferred global determination of the atmospheric angle $θ_{23}$ is consistent with maximal mixing. We also determine the impact of the new data upon all the other neutrino oscillation parameters with emphasis on the increasing sensitivity to the CP phase, thanks to the interplay between accelerator and reactor data. In the appendix we present the updated results obtained after the inclusion of new reactor data presented at the Neutrino 2014 conference. We discuss their impact on the global neutrino analysis.

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arXiv2013

Neutrino mixing with revamped A4 flavour symmetry

We suggest a minimal extension of the simplest A4 flavour model that can induce a nonzero theta13 value, as required by recent neutrino oscillation data from reactors and accelerators. The predicted correlation between the atmospheric mixing angle theta23 and the magnitude of theta13 leads to an allowed region substantially smaller than indicated by neutrino oscillation global fits. Moreover, the scheme correlates CP violation in neutrino oscillations with the octant of the atmospheric mixing parameter theta23 in such a way that, for example, maximal mixing necessarily violates CP. We briefly comment on other phenomenological features of the model.

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arXiv2012

Global status of neutrino oscillation parameters after Neutrino-2012

Here we update the global fit of neutrino oscillations in arXiv:1103.0734 and arXiv:1108.1376 including the recent measurements of reactor antineutrino disappearance reported by the Double Chooz, Daya Bay and RENO experiments, together with latest MINOS and T2K appearance and disappearance results, as presented at the Neutrino-2012 conference. We find that the preferred global fit value of $θ_{13}$ is quite large: $\sin^2θ_{13} \simeq 0.025$ for normal and inverted neutrino mass ordering, with $θ_{13} = 0$ now excluded at more than 10$σ$. The impact of the new $θ_{13}$ measurements over the other neutrino oscillation parameters is discussed as well as the role of the new long-baseline neutrino data and the atmospheric neutrino analysis in the determination of a non-maximal atmospheric angle $θ_{23}$.

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arXiv2011

Lepton flavor violation and non-unitary lepton mixing in low-scale type-I seesaw

Within low-scale seesaw mechanisms, such as the inverse and linear seesaw, one expects (i) potentially large lepton flavor violation (LFV) and (ii) sizeable non-standard neutrino interactions (NSI). We consider the interplay between the magnitude of non-unitarity effects in the lepton mixing matrix, and the constraints that follow from LFV searches in the laboratory. We find that NSI parameters can be sizeable, up to percent level in some cases, while LFV rates, such as that for μ-> e γ, lie within current limits, including the recent one set by the MEG collaboration. As a result the upcoming long baseline neutrino experiments offer a window of opportunity for complementary LFV and weak universality tests.

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