arXiv subjects

O. L. G. Peres

Publications and source records attributed to O. L. G. Peres.

At least 19 recordsLinked to original sources

arXiv2025

Alleviating the present tension between T2K and NO$ν$A with nonstandard neutrino interactions

Since neutrino oscillation was observed, several experiments have been built to measure its parameters. NO$ν$A and T2K are two long-baseline experiments dedicated to measuring mainly the mixing angle $θ_{23}$, the charge-parity conjugation phase $δ_{\rm CP}$, and the mass ordering. However, there is a tension in current data. The T2K allowed region is in conflict with the region allowed by NO$ν$A. We propose a nonstandard charged current interaction (CC-NSI) in neutrino production to relieve this tension. The CC-NSI is computed through quantum field theory (QFT) formalism, where we derive perturbative analytical formulae considering CC-NSI in the pion decay. Within this new approach, we can alleviate NO$ν$A and T2K tension for a CC-NSI complex parameters of order $10^{-3}$. We show the new phase has a degeneracy to the Dirac CP phase of the form $δ_{\rm CP} \pm ϕ= 1.5π$ being a possible source of violation of charge-parity symmetry.

hep-ph↗

arXiv2025

Tau neutrino as a probe of charged non-standard interactions at DUNE

In this work, we study the influence of charged-current non-standard interactions (CC-NSI) at a DUNE-like experiment. We are particularly interested in the tau neutrino channel accessible at DUNE, given the higher energy neutrino flux expected to be achieved by the experiment. We focus on CC-NSI that may affect the pion decay, the primary source of neutrinos for DUNE. We show that the expected sensitivity at the near detector may supersede the present bounds coming directly from pion decay by one order of magnitude.

hep-ph↗

arXiv2023

Quantum decoherence and relaxation in long-baseline neutrino data

We investigate the effect of quantum decoherence and relaxation in neutrino oscillations using MINOS and T2K data. The formalism of open quantum systems is used to describe the interaction of a neutrino system with the environment, where the strength of the interaction is regulated by a decoherence parameter $Γ$. We assume an energy dependence parameterized by $Γ= γ_0 (E/\mbox{GeV})^n$, with $n=-2,0,+2$, and consider three different scenarios, allowing the investigation of the effect of relaxation and of constraining the solar and atmospheric sectors to the same decoherence parameter. The MINOS and T2K data present a complementary behavior, with regard to our theoretical model, resulting in a better sensitivity for $n = +2$ and $n = -2$, respectively. We perform a combined analyses of both experimental data, which also include a reactor constraint on $\sin^2 θ_{13}$, and observe an independence of the results to the scenarios we investigate. As highlight of our analyses we obtain the best limit on $γ_0$ for the energy dependence of $n = -2$, reporting an upper bound of $1.7 \times 10^{-23}$~GeV, at the 90\% confidence level.

hep-ph↗

arXiv2023

On the viability of a light scalar spectrum for 3-3-1 models

In this work we study an effective version of the 3-3-1 model, in which the particle content is the same of the 2HDM. We show that the inherited structure from the $SU(3)_C \otimes SU(3)_L \otimes U(1)_X$ gauge group has a series of consequences, the most relevant one being the prediction of the masses of the neutral scalar to be of the order or lower than the mass of the charged scalar. Given current constraints from collider searches, B-physics, as well as theoretical constraints such as perturbativity of quartic couplings and stability of the scalar potential, we find that the new scalars cannot be lighter than 350 GeV.

hep-ph↗

arXiv2023

Hidden physics in pion and some other meson decays

It has been commonly assumed that pseudoscalar contributions to the leptonic decay of charged mesons, like pions and kaons, is strongly constrained due to the helicity suppression present in the ratio $R_{l/l'} = Γ(P \rightarrow lν[γ])/Γ(P \rightarrow l'ν[γ])$, where $P$ are the charged pseudoscalar meson and $l,l' = e,μ,τ$. Here we show that if the effective couplings are proportional to the corresponding charged lepton masses (and also the PMNS matrix), the constraints from $R_{l/l'}$ are entirely avoided, and a rather new large allowed region is permitted in the parameter space. In the case of the electron, we found a non-trivial region in the range $10^{-4}\lesssim (G^η/G_F) \lesssim 10^{-3}$, where $G^η$ is the effective pseudoscalar coupling associated with a novel charged scalar field, $η$, and $G_F$ is the Fermi constant. Furthermore, we show that this dependence of the pseudoscalar couplings on the charged lepton masses can naturally be associated with a critical class beyond the standard model physics, namely models without (leptonic) flavor-changing neutral currents in the scalar sector. The most known examples are the models that satisfy the so-called Glashow-Weinberg-Paschos theorem. Finally, we also point out that, in those cases, the decay rate is degenerated with the Standard Model prediction, possibly hiding the new physics effects in those decays.

hep-ph↗

arXiv2021

Updating $ν_{3}$ lifetime from solar antineutrino spectra

We study the production of antineutrinos from the solar neutrinos due the Majorana neutrino decays of neutrino to antineutrino. Using the antineutrino spectra from KamLAND and Borexino, we present newest limits on the lifetime of $ν_{3}$ in this scenario. We consider $ν_{3} \rightarrow \barν_{1} + X$ and $ν_{3} \rightarrow \barν_{2} + X$ channels assuming scalar or pseudo-scalar interactions. For hierarchical mass-splittings, the limits obtained by us are $τ_{3}/m_{3}~\geq 7\times 10^{-5} s/eV$ and $τ_{3}/m_{3}~\geq 1\times 10^{-5} s/eV$ for the two channels at $90\%$ C.L. We found that the newest bound is five orders of magnitude better than the atmospheric and long-baseline bounds.

hep-ph↗

arXiv2020

Constraining visible neutrino decay at KamLAND and JUNO

We study visible neutrino decay at the reactor neutrino experiments KamLAND and, JUNO. Assuming the Majoron model of neutrino decay, we obtain constraints on the couplings between Majoron and neutrino as well as on the lifetime/mass of the most massive neutrino state i.e., $τ_{3} / m_{3}$ or $τ_{2} / m_{2}$, respectively, for the normal or the inverted mass orderings. We obtain the constraints on the lifetime $τ_{2} / m_{2} \geq 1.4 \times 10^{-9}~\rm{s/eV}$ in the inverted mass ordering for both KamLAND and JUNO at 90% CL. In the normal ordering in which the bound can be obtained for JUNO only, the constraint is milder than the inverted ordering case, $τ_{3} / m_{3} \geq 1.0 \times 10^{-10}~\rm{s/eV}$ at 90% CL. We find that the dependence of lightest neutrino mass ($=m_{\rm{lightest}}$), $m_1 (m_3)$ for the normal (inverted) mass ordering, on the constraints for the different types of couplings (scalar or pseudo-scalar) is rather strong, but the $m_{\rm{lightest}}$ dependence on the lifetime/mass bound is only modest.

hep-ph↗

arXiv2020

On The Decaying-Sterile Neutrino Solution to the Electron (Anti)Neutrino Appearance Anomalies

We explore the hypothesis that the unexplained data from LSND and MiniBooNE are evidence for a new, heavy neutrino mass-eigenstate that mixes with the muon-type neutrino and decays into an electron-type neutrino and a new, very light scalar particle. We consider two different decay scenarios, one with Majorana neutrinos, one with Dirac neutrinos; both fit the data equally well. We find a reasonable, albeit not excellent, fit to the data of MiniBooNE and LSND. The decaying-sterile-neutrino hypothesis, however, cleanly evades constraints from disappearance searches and precision measurements of leptonic meson decays, as long as $1~{\rm MeV}\gtrsim m_4\gtrsim 10$~keV. The SBN program at Fermilab should be able to definitively test the decaying-sterile-neutrino hypothesis.

hep-ph↗

arXiv2019

Constraining the $3-3-1$ model with heavy neutral leptons using $(g-2)_μ$ and dark matter observables

We find constraints on the highest scale of symmetry breaking of a model with gauge symmetry $SU(3)_C \otimes SU(3)_L \otimes U(1)_X$ with heavy neutral leptons in the fermion triplets, calculating the anomalous magnetic moment of the muon and using results of the relic abundance of dark matter and experiments searching for its direct detection. In order to do this, we have calculated the one-loop contribution of new particles in the model to $(g-2)_μ$, finding a favoured region for the scale at which $SU(3)_L$ is broken, and we have found lower bounds for this scale making a comparison of the predictions for the detection of a fermion dark matter candidate in the model in terms of simplified dark matter models, identifying the dominant portal for its interactions with standard model particles, and using constraints for the relic abundance and spin-independent scattering cross section of the fermion candidate with protons.

hep-ph↗

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.

hep-ph↗

arXiv2017

Impact of standard neutrino oscillations and systematics in proton lifetime measurements

We use atmospheric neutrino phenomenology to obtain the expected background to proton decay in large underground neutrino detectors, like DUNE. We introduced, for the first time in this kind of analysis, the experimentally confirmed neutrino oscillations of the atmospheric neutrino observations which reduce by a factor of 40\% the corresponding background for nucleon decay channel $p\rightarrow μ^{+}+π^{0}$. Furthermore, we infer the impact of four systematics on such background: the overall efficiency, the muon reconstruction energy resolution, the resonant neutral pion cross-section and the neutral pion angular resolution. Considering a 40 kton detector with efficiency 45\%, our analysis leads to an error band in the lower limit for the proton lifetime, from $7.9 \times 10^{33}$~years to {\bf $1.1 \times 10^{34}$}~years at $90\%$~C.L.. These numbers can be compared with the current mode dependent experimental limits $τ> 10^{31}-10^{33}$~years at $90\%$~C.L.. Finally we investigate how this limit can be further improved with the enhancement of the efficiency of the experiment which can be obtained, for instance, with the implementation of the ARAPUCA device in DUNE.

hep-ph↗

arXiv2016

Large, Extra Dimensions at the Deep Underground Neutrino Experiment

We investigate the potential of the long-baseline Deep Underground Neutrino Experiment (DUNE) to study large-extra-dimension (LED) models originally proposed to explain the smallness of neutrino masses by postulating that right-handed neutrinos, unlike all standard model fermion fields, can propagate in the bulk. The massive Kaluza-Klein (KK) modes of the right-handed neutrino fields modify the neutrino oscillation probabilities and can hence affect their propagation. We show that, as far as DUNE is concerned, the LED model is indistinguishable from a $(3 + 3N)$-neutrino framework for modest values of $N$; $N$ = 1 is usually a very good approximation. Nonetheless, there are no new sources of $CP$-invariance violation other than one $CP$-odd phase that can be easily mapped onto the $CP$-odd phase in the standard three-neutrino paradigm. We analyze the sensitivity of DUNE to the LED framework, and explore the capability of DUNE to differentiate the LED model from the three-neutrino scenario and from a generic $(3 + 1)$-neutrino model.

hep-ph↗

arXiv2016

Hidden Interactions of Sterile Neutrinos As a Probe For New Physics

Recent results from neutrino experiments show evidence for light sterile neutrinos which do not have any Standard Model interactions. In this work we study the hidden interaction of sterile neutrinos with an "MeV scale" gauge boson (the $ν_s$HI model) with mass $M_X$ and leptonic coupling $g^\prime_l$. By performing an analysis on the $ν_s$HI model using the data of the MINOS neutrino experiment we find that the values above $G_X/G_F=92.4$ are excluded by more than $2σ$ C.L., where $G_F$ is the Fermi constant and $G_X$ is the field strength of the $ν_s$HI model. Using this model we can also probe other new physics scenarios. We find that the region allowed by the $(g-2)_μ$ discrepancy is entirely ruled out for $M_X\lesssim 100$ MeV. Finally, the secret interaction of sterile neutrinos has been to solve a conflict between the sterile neutrinos and cosmology. It is shown here that such an interaction is excluded by MINOS for $g^\prime_s> 1.6\times10^{-2}$. This exclusion, however, does depend on the value of $g_l^{\prime}$.

hep-ph↗

arXiv2016

Bounds on Neutrino-Scalar Yukawa Coupling

General neutrino-scalar couplings appear in many extensions of Standard Model. We can probe these neutrino-scalar couplings by leptonic decay of mesons and from heavy neutrino search. Our analysis improves the present limits to $|g_e|^2<1.9\times 10^{-6}$ and $|g_μ|^2<1.9\times 10^{-7}$ at 90\% C.L. for massless scalars. For massive scalars we found for the first time the constraints for $g^2_α$ couplings to be $10^{-6}-10^{-1}$ respectively for scalar masses between below 1 MeV and for 300 MeV.

hep-ph↗

arXiv2015

Neutrino Decay and Solar Neutrino Seasonal Effect

We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the $ν_2$ neutrino lifetime at $τ_2\, /\, m_2 \geq 7.2 \times 10^{-4}\,\,\hbox{s}\,.\,\hbox{eV}^{-1}$ at $99\%\,$C.L.. Also, we show how seasonal variations in the solar neutrino data can give interesting additional information about neutrino lifetime.

hep-ph↗

arXiv2015

Confronting the Stochastic Neutrino Mixing Mechanism and the sterile neutrino hypothesis as a solution to the short baseline neutrino anomalies

We compare the solutions to the short baseline neutrino anomaly based on oscillations to sterile neutrinos and the Stochastic Neutrino Mixing Mechanism (SNMM) through an analysis of the present neutrino data. The SNMM suggests worse fits than a 3 + 1 sterile neutrino model, although it cannot be discarded by present data. We propose an experiment to distinguish between both solutions, based on placing a $^8$Li source inside a 5kton-yr detector (like SNO). We studied the sensitivity of such an experiment, which makes it possible to discriminate within $2σ$ the SNMM from the 3+1 sterile hypothesis for some particular values of the relevant parameters in 5 kton-years of running.

hep-ph↗

arXiv2014

Constraints on neutrino decay lifetime using long-baseline charged and neutral current data

We investigate the status of a scenario involving oscillations and decay for charged and neutral current data from the MINOS and T2K experiments. We first present an analysis of charged current neutrino and anti-neutrino data from MINOS in the framework of oscillation with decay and obtain a best fit for non-zero decay parameter $α_3$. The MINOS charged and neutral current data analysis results in the best fit for $|Δm_{32}^2| = 2.34\times 10^{-3}$~eV$^2$, $\sin^2 θ_{23} = 0.60$ and zero decay parameter, which corresponds to the limit for standard oscillations. Our combined MINOS and T2K analysis reports a constraint at the 90\% confidence level for the neutrino decay lifetime $τ_3/m_3 > 2.8 \times 10^{-12}$~s/eV. This is the best limit based only on accelerator produced neutrinos.

hep-ph↗

arXiv2014

Probing Large Extra Dimensions With IceCube

In models with Large Extra Dimensions the smallness of neutrino masses can be naturally explained by introducing gauge singlet fermions which propagate in the bulk. The Kaluza-Klein modes of these fermions appear as towers of sterile neutrino states on the brane. We study the phenomenological consequences of this picture for the high energy atmospheric neutrinos. For this purpose we construct a detailed equivalence between a model with large extra dimensions and a (3 + n) scenario consisting of three active and n extra sterile neutrino states, which provides a clear intuitive understanding of Kaluza-Klein modes. Finally, we analyze the collected data of high energy atmospheric neutrinos by IceCube experiment and obtain bounds on the radius of extra dimensions.

hep-ph↗