Majorana vs Pseudo-Dirac Neutrinos at the ILC

Neutrino masses could originate in seesaw models testable at colliders, with light mediators and an approximate lepton number symmetry. The minimal model of this type contains two quasi-degenerate Majorana fermions forming a pseudo-Dirac pair. An important question is to what extent future colliders will have sensitivity to the splitting between the Majorana components, since this quantity signals the breaking of lepton number and is connected to the light neutrino masses. We consider the production of these neutral heavy leptons at the ILC, where their displaced decays provide a golden signal: a forward-backward charge asymmetry, which depends crucially on the mass splitting between the two Majorana components. We show that this observable can constrain the mass splitting to values much lower than current bounds from neutrinoless double beta decay and natural loop corrections.Comment: 16 pages, 5 figures; v2: Minor changes, version accepted for publication in EPJ

Can SUSY relax LNV constraints coming from loop corrections to light neutrino masses on the low-scale Seesaw?

Heavy neutrinos from the Type-I Seesaw model can have a large mixing with active states, motivating their search at collider experiments. However, loop corrections to light neutrino masses constrain the heavy neutrinos to appear in pseudo-Dirac pairs, leading to a potential suppression of lepton number violating parameters. In this work we perform a detailed review of a proposal to relax constraints on lepton number violation by adding supersymmetry. We define the conditions necessary to maximise the SUSY screening effect, with the objective of allowing a larger mass splitting between low-scale heavy neutrino masses. We find that the sole addition of SUSY does not guarantee a screening, and that favourable cases have some degree of fine-tuning.Comment: 10 figure

Modificación hidrotérmica del almidón de yuca para su empleo como estabilizador de helados

En el trabajo se desarrolla un procedimiento de modificación física de almidón nativo de yuca a través de un tratamiento hidrotérmico en la zona previa a la gelatinización, de la cual no existen reportes de experimentación. El objetivo es determinar la influencia de las principales variables del proceso sobre el comportamiento reológico, con el propósito de ser empleado como estabilizador en la Industria heladera. Se alcanzaron buenos resultados reológicos con una concentración de 6% p/p de almidón nativo a 56 0C. El material obtenido se usó en formulaciones de helados, sustituyendo parte de los productos convencionales con efectos muy positivos en cuanto a la evaluación sensorial y el índice de aireación. Los resultados alcanzados permiten establecer perspectivas para el empleo de almidones modificados de yuca cuyo tratamiento hidrotérmico en la zona previa a la gelatinización ofrece efectos positivos, como estabilizante de suspensiones acuosas, similares a los que se alcanzan con almidones pregelatinizados, además con la ventaja de obtener el producto modificado con mayor facilidad

Empleo de recubrimientos comestibles con base en almidón de papa y yuca en la conservación del mango cv. Zapote

Se evaluó el uso de la aplicación de un recubrimiento comestible con base de almidón de yuca nativa y almidón de papa, en concentraciones de 4 y 10 %, al mango, en estado verde. Inicialmente fueron desinfectados en hipoclorito de sodio a 200 ppm, por un tiempo de 3 minutos. El tratamiento (1), corresponde a 4% de almidón de yuca, en combinación, de 20% de glicerol, en cuanto a materia seca y 5% de lecitina de soya, el tratamiento (2) contiene 10% de almidón de papa en combinación de lecitina de soja (5%) y glicerol (20%) en cuanto a materia seca. Los resultados obtenidos en la evolución de las características fisicoquímicas del mango variedad zapote fueron analizados estadísticamente empleando el paquete SPSS versión 13, aplicándose el análisis de la varianza (ANOVA), y nivel de significancia del 5%. Las variables de respuesta que se estudiaron fueron color, pérdida de peso, forma-tamaño, firmeza, pH, SST, acidez, tasa de respiración con el fin de establecer si el tipo y la concentración de almidón influyen significativamente en la conservación del mango en estado verde almacenado a granel a condiciones de ambiente de Pamplona. Al evaluar la influencia de los recubrimientos en la conservación del mango variedad zapote se obtuvo que al emplear almidón de yuca al 4% y sorbato de potasio al 0,05% en el recubrimiento comestible se logra controlar la maduración organoléptica por un periodo de 12 días, extendiéndose 6 días de vida útil en almacenamiento a granel en condiciones ambientales de Pamplona

Magnetic order of Cr thin films in Nb/Cr/Fe-nanoisland hybrid: a comparative study between magnetic and superconducting properties

Shifted hysteresis loops characteristic of the exchange bias effect between a ferromagnet and an antiferromagnet are demonstrated in structures formed by a 2.5 nm Cr layer deposited on top of an array of Fe nanoislands (Cr/Fe-nanoislands). This effect evidences the persistence of antiferromagnetic (AF) order for Cr layers much thinner than the thickness reported in the literature. The field shift measured is found to increase for the smallest island sizes, which can be related with the enhancement of the Fe-nanoisland surface to volume ratio. The comparative study between superconducting proximity effects in Nb/Cr/Fe-nanoislands and Nb/normal metal/Fe-nanoisland hybrids (where the normal metals used are Al and Pt) confirms the presence of AF order in the 2.5 nm Cr spacer layer. A much shorter penetration depth of the Cooper pairs into the AF Cr layers than in the normal metal Pt and Al spacer layers is deduced

Comparación de la percepción social en playas recreativas arenosas de dos bahías localizadas en el Pacífico Mexicano

En el presente trabajo se desarrollaron dos formatos de encuesta, para incorporar la percepción de los usuarios a la evaluación de la calidad de las playas (Cervantes, 2006 y Silva-Iñiguez, 2006); ambos basados en un modelo cuantitativo para revelar la percepción social de las playas localizadas en la bahía de Santiago, Manzanillo, Col (MZO) y en Acapulco, Gro (ACA). Se aplicaron un total de 790 encuestas (ACA: 390 y MZO: 400), que permitieron conocer el perfil de los usuarios, sus hábitos de recreación y sus opiniones sobre las condiciones biofísicas y de infraestructura de cada playa. En ambas playas la mayoría prefirieron asistir acompañados por sus familias; las principales actividades recreativas fueron nadar, descansar, comer y beber. En general las demandas en ambos sitios coincidieron con incrementar el número de botes de basura, la frecuencia en el servicio de recolección y limpieza, baños y regaderas. Las razones por la que los usuarios seleccionaron la playa a visitar fueron la seguridad y vigilancia, así como las características biofísicas de la misma. La incorporación de esta información a modelos y/o esquemas de evaluación y gestión de playa (a través de índices ambientales) permitió realizar la valoración integral de la playa.In this paper it was developed two survey formats, to include the perception of users on the assessment of the quality of the beaches (Cervantes, 2006 and Silva-Iñiguez, 2006), both based on a quantitative model to reveal the social perception of the beaches on Santiago Bay, Manzanillo, Col (MZO) and Acapulco, Guerrero (ACA). We did a total of 790 surveys (ACA: 390 and MZO: 400), which allowed the user profile, recreation habits and their views on the biophysical and infrastructure of each beach. In both beaches, most people, attended with their families, the main recreational activities were swimming, resting, eating and drinking. In general the demands on both sites agreed to increase the number of waste baskets, the frequency of collection service and cleaning bathrooms and showers. The reasons why the users selected to visit the beach were the safety and security, as well as the biophysical characteristics of the same. Incorporating this information to models and / or evaluation schemes and beach management (through environmental ratings) allowed the comprehensive assessment of the beach

Global Distribution of Key Features of Streamer Corona Discharges in Thunderclouds

We present nighttime worldwide distributions of key features of Blue LUminous Events (BLUEs) detected by the Modular Multispectral Imaging Array of the Atmosphere-Space Interaction Monitor. Around 10% of all detected BLUEs exhibit an impulsive single pulse shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density <25 µWm−2 (common) and ≥25 µWm−2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤4 km in the tropics and ≤1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to ∼4 km height) and have the largest number of streamers (up to ∼3 × 109). Additionally, the analysis of BLUEs has turned out to be particularly complex due to the abundance of radiation belt particles (at high latitudes and in the South Atlantic Anomaly [SAA]) and cosmic rays all over the planet. True BLUEs can not be fully distinguished from radiation belt particles and cosmic rays unless other ground-based measurements associated with the optically detected BLUEs are available. Thus, the search algorithm of BLUEs presented in Soler et al. (2021), https://doi.org/10.1029/2021gl094657 is now completed with a new additional step that, if used, can considerably smooth the SAA shadow but can also underestimate the number of BLUEs worldwide.publishedVersio

Exploración en los sistemas CRM/ERP como estrategia en el sector PYMES

This article exploration, in the CRM/ ERP context for SME’s seeks to have an understanding of a sector that is sustainable for a country, as it is SMEs. Besides to know through the years the constant changes that have fortuitously emerged, how it has been evolving and adapting to them, to be profitable in the competitive environment of today. Nevertheless, in the case study facts they arise which offer more truthful understanding of how favorable opting for information systems processes and investment returns in the short and long term for SMEs.Este resumen de exploración en el contexto de CRM/ERP para PYMES, busca contar con un entendimiento de un sector que es de carácter sostenible para un país, como lo son las PYMES. Además, conocer a través de los años los constantes cambios que han surgido fortuitamente, como esta ha estado evolucionando, y se ha adaptado a los mismos, para ser rentable en el entorno competitivo de hoy. Además, cómo se identifica con la utilización de sistemas integrados de información (CRM /ERP), para una efectiva gestión en la cadena de abastecimiento (SCM) y su nivel de aplicabilidad, en el importante sector económico que cubren las pequeñas y mediana empresas. Por tal motivo, en el caso de estudio se plantean hechos concretos que ofrecen un entendimiento más verídico, de lo favorable de optar por sistemas de información de procesos, y los retornos de inversión a corto y largo plazo para las PYMES

Einstein's quantum theory of the monatomic ideal gas: non-statistical arguments for a new statistics

In this article, we analyze the third of three papers, in which Einstein presented his quantum theory of the ideal gas of 1924-1925. Although it failed to attract the attention of Einstein's contemporaries and although also today very few commentators refer to it, we argue for its significance in the context of Einstein's quantum researches. It contains an attempt to extend and exhaust the characterization of the monatomic ideal gas without appealing to combinatorics. Its ambiguities illustrate Einstein's confusion with his initial success in extending Bose's results and in realizing the consequences of what later became to be called Bose-Einstein statistics. We discuss Einstein's motivation for writing a non-combinatorial paper, partly in response to criticism by his friend Ehrenfest, and we paraphrase its content. Its arguments are based on Einstein's belief in the complete analogy between the thermodynamics of light quanta and of material particles and invoke considerations of adiabatic transformations as well as of dimensional analysis. These techniques were well-known to Einstein from earlier work on Wien's displacement law, Planck's radiation theory, and the specific heat of solids. We also investigate the possible role of Ehrenfest in the gestation of the theory.Comment: 57 pp