Sterile neutrinos, dark matter, and resonant effects in ultra high energy regimes

Interest in light dark matter candidates has recently increased in the literature; some of these works consider the role of additional neutrinos, either active or sterile. Furthermore, extragalactic neutrinos have been detected with energies higher than have ever been reported before. This opens a new window of opportunities to the study of neutrino properties that were unreachable up to now. We investigate how an interaction potential between neutrinos and dark matter might induce a resonant enhancement in the oscillation probability, an effect that may be tested with future neutrino data.Comment: 11 pages, 2 figures, to be published in PL

The reactor antineutrino anomaly and low energy threshold neutrino experiments

Short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. In this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. We discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. We find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. We also analyse the measurements of antineutrino scattering off electrons from short distance reactor experiments. In this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the Gallium anomaly.Comment: 9 pages, 6 figures, 1 table, matches published versio

Effects of charge symmetry breaking on form factors of the pion and kaon

Effects of charge symmetry breaking associated with the $u$ and $d$ quark mass difference in the elastic form factors of the pion and kaon are presented. We use a confining version of the Nambu--Jona-Lasinio model. The pion and kaon are described as a dressed quark and antiquark bound states governed by the Bethe-Salpeter equation, and exhibit the properties of Goldstone bosons, with the pion mass difference given by $m_{\pi^{+}}^2 - m_{\pi^{0}}^2 \propto (m_u -m_d)^2$ as demanded by dynamical chiral symmetry breaking. We found significant charge symmetry breaking effects for realistic current quark mass ratios ($m_u/m_d \sim 0.5$) in the quark electromagnetic form factors of the pion and kaon. We also report the effects of charge symmetry breaking on the parton distribution functions, which are rather smaller than those found in the electromagnetic form factors.Comment: 4 pages, 5 figures, accepted version for the QNP2018 proceedings, 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba, Ibaraki, Japa

Rise in the frequency of cloud cover in LANDSAT data for the period 1973 to 1981

Percentages of cloud cover in LANDSAT imagery were used to calculate the cloud cover monthly average statistic for each LANDSAT scene in Brazil, during the period of 1973 to 1981. The average monthly cloud cover and the monthly minimum cloud cover were also calculated for the regions of north, northeast, central west, southeast and south, separately

Sampling system for wheat (Triticum aestivum L) area estimation using digital LANDSAT MSS data and aerial photographs

A procedure to estimate wheat (Triticum aestivum L) area using sampling technique based on aerial photographs and digital LANDSAT MSS data is developed. Aerial photographs covering 720 square km are visually analyzed. To estimate wheat area, a regression approach is applied using different sample sizes and various sampling units. As the size of sampling unit decreased, the percentage of sampled area required to obtain similar estimation performance also decreased. The lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation is 13.90% using 10 square km as the sampling unit. Wheat area estimation using only aerial photographs is less precise and accurate than those obtained by regression estimation

Estimation of the sugar cane cultivated area from LANDSAT images using the two phase sampling method

A two phase sampling method and the optimal sampling segment dimensions for the estimation of sugar cane cultivated area were developed. This technique employs visual interpretations of LANDSAT images and panchromatic aerial photographs considered as the ground truth. The estimates, as a mean value of 100 simulated samples, represent 99.3% of the true value with a CV of approximately 1%; the relative efficiency of the two phase design was 157% when compared with a one phase aerial photographs sample

Analysis of Perceptions of Milk Consumption and Customer Service in the City of Riobamba, Province of Chimborazo

The customer has become a source of strategic information about the quality of products and services. For this reason, the objective of this research was to analyze the level of service and mental processes of clients in making decisions to consume milk in the province of Chimborazo. Non-probabilistic sampling was used and data were collected from 50 clients and 75 representatives of small- and medium-sized companies in the city of Riobamba which participated in the Production Exhibition, Macají, Riobamba 2019. An electroencephalogram was used to determine whether the purchasing decisions were made at the unconscious level by reading brain waves. Three brands of milk that are sold locally were used. The study revealed that there were representative differences in stimulating people to different perceptions (visual, olfactory, gustatory) that influence the appreciation and purchasing decisions of milk. Similarly, it was found that there are decisions that the consumer makes unconsciously based on memories and past experiences that influence their present behavior at the time of consumption. The study also revealed the need to improve the level of service. Keywords: neuromarketing, perception, strategies, service level. Resumen El cliente se ha convertido en una fuente de información estratégica sobre la calidad del producto y del servicio. Por este motivo, el objetivo del artículo científico fue analizar el nivel de servicio y los procesos mentales del cliente para la toma las decisiones de consumir leche en la provincia de Chimborazo. El estudio se realizó mediante un muestreo no probabilístico con informaciones de 50 clientes y 75 representantes de pequeñas y medianas empresas de la ciudad de Riobamba que participaron en la Exposición de Producción, Macají, Riobamba 2019. Se utilizó el electroencefalograma para determinar si las decisiones de compra se realizan a nivel inconsciente mediante la lectura de ondas cerebrales. Para ello se utilizaron tres marcas de leche que se comercializan en la localidad. El estudio reveló que existen diferencias representativas al estimular a las personas a diferentes percepciones (visual, olfativa, gustativa) que influyen en la apreciación y decisión de compra de la leche. De igual modo, se constató que existen decisiones que realiza el consumidor de manera inconsciente basada en los recuerdos y experiencias del pasado que influyen en su comportamiento presente al momento del consumo. Asimismo, el estudio reveló la necesidad de mejorar el nivel de servicio. Palabras clave: neuromarketing, percepción, estrategias, nivel de servicio