Orlando Peres - Academia.edu (original) (raw)

Papers by Orlando Peres

Research paper thumbnail of Testing non-standard neutrino interactions in (anti)-electron neutrino disappearance experiments

Journal of High Energy Physics

We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappea... more We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappearance in oscillation data. We found a slight preference for non-zero CP violation, coming from both tensor and scalar interactions. The preference for CP violation is led by Daya Bay low-energy data with a significance that reaches ~ 1.7σ in the global analysis (and ~ 2.1σ when considering only medium baseline reactors data) compared to the standard neutrino oscillation scenario. In some cases, our results indicate that the atmospheric mass squared difference falls outside the range allowed by accelerator long baseline experiments. This suggests the need for further investigation in future work.

Research paper thumbnail of Construction of precision wire readout planes for the Short-Baseline Near Detector (SBND)

Journal of Instrumentation, 2020

Baseline Near Detector time projection chamber is unique in the design of its charge readout plan... more Baseline Near Detector time projection chamber is unique in the design of its charge readout planes. These anode plane assemblies (APAs) have been fabricated and assembled to meet strict accuracy and precision requirements: wire spacing of 3 mm ± 0.5 mm and wire tension of 7 N ± 1 N across 3,964 wires per APA, and flatness within 0.5 mm over the 4 m × 2.5 m extent of each APA. This paper describes the design, manufacture and assembly of these key detector components, with a focus on the quality assurance at each stage.

Research paper thumbnail of New limits on neutrino magnetic moment through nonvanishing 13-mixing

Research paper thumbnail of Neutrino decay and solar neutrino seasonal effect

Physics Letters B, 2016

We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation ... more 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 ν2 neutrino lifetime at τ2 / m2 ≥ 7.2 × 10 −4 s. 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.

Research paper thumbnail of Stochastic neutrino mixing mechanism

Research paper thumbnail of O experimento de oscilação de neutrinos no reator de Angra dos Reis

Physicae, 2006

Apresentamos aqui o status e os planos do projeto ANGRA, um novo experimento de oscilação de neut... more Apresentamos aqui o status e os planos do projeto ANGRA, um novo experimento de oscilação de neutrinos em reatores, proposto para ser montado no complexo nuclear de Angra dos Reis. Este experimento destina-se a medir oângulo θ13, oúltimo dos tresângulos de mistura no setor de neutrinos ainda sem uma medida positiva. Propõe-se neste projeto um experimento de multi-detecção com alta sensitividade, capaz de atingir uma sensibilidade na detecção de desaparecimento de anti-neutrinos da ordem de sin 2 2θ13 = 0.006 em três anos de funcionamento, combinando uma alta luminosidade, baixo ruído em raios cósmicos e um controle cuidadoso dos erros sistemáticos. Planeja-se também explorar a possibilidade de usar a detecção de neutrinos para fins de salvaguarda e não-proliferação de armas nucleares.

Research paper thumbnail of An updated analysis on atmospheric neutrinos

Progress in Particle and Nuclear Physics, 1998

We have reanalysed the atmospheric neutrino data including new results from Super-Kamiokande and ... more We have reanalysed the atmospheric neutrino data including new results from Super-Kamiokande and Soudan-II experiments, under the assumption of two-flavor neutrino oscillation. We present the allowed region of oscillation parameters for the νµ → ντ channel. In performing this re-analysis we also take into account some recent theoretical improvements in the flux calculations.

Research paper thumbnail of Atmospheric Neutrino Observations and Flavor Changing Interactions

Physical Review Letters, 1999

Research paper thumbnail of Mass varying neutrinos in supernovae

Research paper thumbnail of Limits on Majorana neutrinos from recent experimental data

Physical Review D, 1999

We investigate the sensitivity of some weak processes to the simplest extension of the Standard M... more We investigate the sensitivity of some weak processes to the simplest extension of the Standard Model with Majorana neutrinos mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data and the most recent neutrinoless double-β decay limit were found.

Research paper thumbnail of Some consequences in weak processes of three-generation mixing in the leptonic sector

Physical Review D, 1994

%le investigate the sensitivity of some weak processes to a Cabibbo-Kobayashi-Maskawa mixing in t... more %le investigate the sensitivity of some weak processes to a Cabibbo-Kobayashi-Maskawa mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data were found. We discuss in this context neutrino oscillations and cosmological and astrophysical consequences as well.

Research paper thumbnail of Measuring the spectra of high energy neutrinos with a kilometer-scale neutrino telescope

Physical Review D, 2003

We investigate the potential of a future kilometer-scale neutrino telescope such as the proposed ... more We investigate the potential of a future kilometer-scale neutrino telescope such as the proposed IceCube detector in the South Pole, to measure and disentangle the yet unknown components of the cosmic neutrino flux, the prompt atmospheric neutrinos coming from the decay of charmed particles and the extra-galactic neutrinos, in the 10 TeV to 1 EeV energy range. Assuming a power law type spectra, dφ ν /dE ν ∼ αE β ν , we quantify the discriminating power of the IceCube detector and discuss how well we can determine magnitude (α) as well as slope (β) of these two components of the high energy neutrino spectrum, taking into account the background coming from the conventional atmospheric neutrinos.

Research paper thumbnail of Massless “just-so” solution to the solar neutrino problem

Research paper thumbnail of Angra Neutrino Project: status and plans

Nuclear Physics B - Proceedings Supplements, 2006

We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation ... more We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex. This experiment is aimed to measure θ13, the last unknown of the three neutrino mixing angles. Combining a high luminosity design, very low background from cosmic rays and careful control of systematic errors at the 1% level, we propose a high sensitivity multi-detector experiment, able to reach a sensitivity to antineutrino disappearance down to sin 2 2θ13 = 0.006 in a three years running period, improving present limits constrained by the CHOOZ experiment by more than an order of magnitude.

Research paper thumbnail of Random magnetic fields inducing solar neutrino spin-flavor precession in a three generation context

Journal of Physics: Conference Series, 2006

Research paper thumbnail of Angra dos Reis reactor neutrino oscillation experiment

Brazilian Journal of Physics, 2006

Research paper thumbnail of Testing flavor changing neutrino interactions in long baseline experiments

Research paper thumbnail of Three generations mixing and’TAU’decay puzzle

We consider the possibility that the τ decay puzzle is a consequence of the Kobayashi-Maskawa mix... more We consider the possibility that the τ decay puzzle is a consequence of the Kobayashi-Maskawa mixing in the leptonic sector.

Research paper thumbnail of Flavor changing models with strictly massless neutrinos

Theoretical models which present flavor changing neutrino interactions and simultaneously prevent... more Theoretical models which present flavor changing neutrino interactions and simultaneously prevent this particle from acquiring any mass exist. We discuss some of them and their predictions for neutrino oscillations in matter which can account for the solar neutrino anomaly as well as the zenith-angle dependence of the deficit of atmospheric neutrinos observed by the SuperKamiokande experiment without invoking, therefore, neutrino masses nor mixing.

Research paper thumbnail of The effect of random magnetic fields in solar neutrino spin-flavor precession

, bra-guzzo-MM-abs1-he22-poster We study the effect of random magnetic fields in the spin-flavor ... more , bra-guzzo-MM-abs1-he22-poster We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a non-vanishing transition magnetic moment is assumed. While this kind of precession is strongly constrained when the magnetic moment involves the first family, such constraints do not apply if we suppose a transition magnetic moment between the second and third families. In this scenario we can have a large non-electron anti-neutrino flux arriving on Earth, which can lead to some interesting phenomenological consequences, as, for instance, the suppression of day-night asymmetry. We have analyzed the high energy solar neutrino data and the KamLAND experiment to constrain the solar mixing angle, ¤ ¦ ¥ § © , and solar mass difference, , and we have found a larger shift of allowed values.

Research paper thumbnail of Testing non-standard neutrino interactions in (anti)-electron neutrino disappearance experiments

Journal of High Energy Physics

We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappea... more We search for scalar and tensor non-standard interactions using (anti)-electron neutrino disappearance in oscillation data. We found a slight preference for non-zero CP violation, coming from both tensor and scalar interactions. The preference for CP violation is led by Daya Bay low-energy data with a significance that reaches ~ 1.7σ in the global analysis (and ~ 2.1σ when considering only medium baseline reactors data) compared to the standard neutrino oscillation scenario. In some cases, our results indicate that the atmospheric mass squared difference falls outside the range allowed by accelerator long baseline experiments. This suggests the need for further investigation in future work.

Research paper thumbnail of Construction of precision wire readout planes for the Short-Baseline Near Detector (SBND)

Journal of Instrumentation, 2020

Baseline Near Detector time projection chamber is unique in the design of its charge readout plan... more Baseline Near Detector time projection chamber is unique in the design of its charge readout planes. These anode plane assemblies (APAs) have been fabricated and assembled to meet strict accuracy and precision requirements: wire spacing of 3 mm ± 0.5 mm and wire tension of 7 N ± 1 N across 3,964 wires per APA, and flatness within 0.5 mm over the 4 m × 2.5 m extent of each APA. This paper describes the design, manufacture and assembly of these key detector components, with a focus on the quality assurance at each stage.

Research paper thumbnail of New limits on neutrino magnetic moment through nonvanishing 13-mixing

Research paper thumbnail of Neutrino decay and solar neutrino seasonal effect

Physics Letters B, 2016

We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation ... more 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 ν2 neutrino lifetime at τ2 / m2 ≥ 7.2 × 10 −4 s. 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.

Research paper thumbnail of Stochastic neutrino mixing mechanism

Research paper thumbnail of O experimento de oscilação de neutrinos no reator de Angra dos Reis

Physicae, 2006

Apresentamos aqui o status e os planos do projeto ANGRA, um novo experimento de oscilação de neut... more Apresentamos aqui o status e os planos do projeto ANGRA, um novo experimento de oscilação de neutrinos em reatores, proposto para ser montado no complexo nuclear de Angra dos Reis. Este experimento destina-se a medir oângulo θ13, oúltimo dos tresângulos de mistura no setor de neutrinos ainda sem uma medida positiva. Propõe-se neste projeto um experimento de multi-detecção com alta sensitividade, capaz de atingir uma sensibilidade na detecção de desaparecimento de anti-neutrinos da ordem de sin 2 2θ13 = 0.006 em três anos de funcionamento, combinando uma alta luminosidade, baixo ruído em raios cósmicos e um controle cuidadoso dos erros sistemáticos. Planeja-se também explorar a possibilidade de usar a detecção de neutrinos para fins de salvaguarda e não-proliferação de armas nucleares.

Research paper thumbnail of An updated analysis on atmospheric neutrinos

Progress in Particle and Nuclear Physics, 1998

We have reanalysed the atmospheric neutrino data including new results from Super-Kamiokande and ... more We have reanalysed the atmospheric neutrino data including new results from Super-Kamiokande and Soudan-II experiments, under the assumption of two-flavor neutrino oscillation. We present the allowed region of oscillation parameters for the νµ → ντ channel. In performing this re-analysis we also take into account some recent theoretical improvements in the flux calculations.

Research paper thumbnail of Atmospheric Neutrino Observations and Flavor Changing Interactions

Physical Review Letters, 1999

Research paper thumbnail of Mass varying neutrinos in supernovae

Research paper thumbnail of Limits on Majorana neutrinos from recent experimental data

Physical Review D, 1999

We investigate the sensitivity of some weak processes to the simplest extension of the Standard M... more We investigate the sensitivity of some weak processes to the simplest extension of the Standard Model with Majorana neutrinos mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data and the most recent neutrinoless double-β decay limit were found.

Research paper thumbnail of Some consequences in weak processes of three-generation mixing in the leptonic sector

Physical Review D, 1994

%le investigate the sensitivity of some weak processes to a Cabibbo-Kobayashi-Maskawa mixing in t... more %le investigate the sensitivity of some weak processes to a Cabibbo-Kobayashi-Maskawa mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data were found. We discuss in this context neutrino oscillations and cosmological and astrophysical consequences as well.

Research paper thumbnail of Measuring the spectra of high energy neutrinos with a kilometer-scale neutrino telescope

Physical Review D, 2003

We investigate the potential of a future kilometer-scale neutrino telescope such as the proposed ... more We investigate the potential of a future kilometer-scale neutrino telescope such as the proposed IceCube detector in the South Pole, to measure and disentangle the yet unknown components of the cosmic neutrino flux, the prompt atmospheric neutrinos coming from the decay of charmed particles and the extra-galactic neutrinos, in the 10 TeV to 1 EeV energy range. Assuming a power law type spectra, dφ ν /dE ν ∼ αE β ν , we quantify the discriminating power of the IceCube detector and discuss how well we can determine magnitude (α) as well as slope (β) of these two components of the high energy neutrino spectrum, taking into account the background coming from the conventional atmospheric neutrinos.

Research paper thumbnail of Massless “just-so” solution to the solar neutrino problem

Research paper thumbnail of Angra Neutrino Project: status and plans

Nuclear Physics B - Proceedings Supplements, 2006

We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation ... more We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex. This experiment is aimed to measure θ13, the last unknown of the three neutrino mixing angles. Combining a high luminosity design, very low background from cosmic rays and careful control of systematic errors at the 1% level, we propose a high sensitivity multi-detector experiment, able to reach a sensitivity to antineutrino disappearance down to sin 2 2θ13 = 0.006 in a three years running period, improving present limits constrained by the CHOOZ experiment by more than an order of magnitude.

Research paper thumbnail of Random magnetic fields inducing solar neutrino spin-flavor precession in a three generation context

Journal of Physics: Conference Series, 2006

Research paper thumbnail of Angra dos Reis reactor neutrino oscillation experiment

Brazilian Journal of Physics, 2006

Research paper thumbnail of Testing flavor changing neutrino interactions in long baseline experiments

Research paper thumbnail of Three generations mixing and’TAU’decay puzzle

We consider the possibility that the τ decay puzzle is a consequence of the Kobayashi-Maskawa mix... more We consider the possibility that the τ decay puzzle is a consequence of the Kobayashi-Maskawa mixing in the leptonic sector.

Research paper thumbnail of Flavor changing models with strictly massless neutrinos

Theoretical models which present flavor changing neutrino interactions and simultaneously prevent... more Theoretical models which present flavor changing neutrino interactions and simultaneously prevent this particle from acquiring any mass exist. We discuss some of them and their predictions for neutrino oscillations in matter which can account for the solar neutrino anomaly as well as the zenith-angle dependence of the deficit of atmospheric neutrinos observed by the SuperKamiokande experiment without invoking, therefore, neutrino masses nor mixing.

Research paper thumbnail of The effect of random magnetic fields in solar neutrino spin-flavor precession

, bra-guzzo-MM-abs1-he22-poster We study the effect of random magnetic fields in the spin-flavor ... more , bra-guzzo-MM-abs1-he22-poster We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a non-vanishing transition magnetic moment is assumed. While this kind of precession is strongly constrained when the magnetic moment involves the first family, such constraints do not apply if we suppose a transition magnetic moment between the second and third families. In this scenario we can have a large non-electron anti-neutrino flux arriving on Earth, which can lead to some interesting phenomenological consequences, as, for instance, the suppression of day-night asymmetry. We have analyzed the high energy solar neutrino data and the KamLAND experiment to constrain the solar mixing angle, ¤ ¦ ¥ § © , and solar mass difference, , and we have found a larger shift of allowed values.