Neutrino oscillations and CP violation: analysis of NOvA data

Màster Oficial d'Astrofísica, Física de Partícules i Cosmologia, Facultat de Física, Universitat de Barcelona, Curs: 2015-2016, Tutora: Ma Concepción González GarcíaThis work represents the initiation of the author into research in the phenomenology of neutrino oscillations in the present experimental context. As a start, the formalism and most important aspects of neutrino oscillation phenomenology are reviewed in Chapter 1. Additionally, a brief overview of the different experiments that have led to the current global picture is presented, giving particular attention to accelerator neutrino experiments.The original part of this work focuses on the analysis of the results from the NOvA experiment, the latest in the neutrino oscillation experimental programme, with the aim of quantifying their impact in the present understanding of neutrino oscillation parameters

Leptonic CP Violation and its Origin

[eng] At the end of the 20th century, experiments studying neutrinos coming from the Sun and cosmic rays hitting the atmosphere revealed that these particles can change their flavour, behaving in a way that the Standard Model (SM) explicitly forbids. The quest for understanding the properties of neutrinos, which may reveal the next underlying structure of Nature, has since then led thousands of scientists. The scenario when this thesis was initiated was driven by the latest experimental surprise that neutrinos provided: the initial hints towards their strong violation of the particle-antiparticle CP symmetry. Characterising the statistical significance, robustness and physical origin of that hint is the main goal that this work pursuits. For that, there is a rich programme of present and future long baseline (LBL) accelerator neutrino experiments. At the beginning of the development of this thesis, the LBL accelerator neutrino experiment NOvA released its first data. To obtain a global picture, this work combines it with the results of other relevant neutrino experiments. The status of leptonic mixing and CP violation is quantitatively assessed as LBL accelerator neutrino experiments kept releasing data. As the unknowns start getting clarified, the data points towards maximal CP violation. This hint is driven by an excess of electron neutrino appearance events in the LBL accelerator experiment T2K. In the three massive neutrino paradigm and with the other leptonic mixing parameters accurately measured by different experiments, the excess can only be accommodated by large CP violation. Nevertheless, three massive neutrinos is just a minimal extension of the SM: other new physics could be present, masking the results as direct leptonic CP violation has not yet been conclusively observed. This thesis confronts with data the scenario that is less bounded by other experiments: neutral current Non-Standard Interactions (NSI) among neutrinos and matter. Physically, they are generated by new interactions among neutrinos and matter mediated by potentially light particles. Due to the large parameter space involved, first just CP-conserving NSI (i.e., their moduli) are explored. Current bounds are evaluated, as well as the synergies and complementarity among different experiments. Thanks to the experiments working with various neutrino energies and travelled distances, the determination of leptonic mixing parameters is found to be quite robust. Thus, it is possible to move on and evaluate the current sensitivity to leptonic CP violation assuming the most generic CP-violating NSI are present. CP violation induced by neutrino masses and leptonic mixing is found to be quite robust, due to the large amount of neutrino flavour transition data collected along three decades. Nevertheless, the next generation LBL accelerator experiments are aimed at precision measurements that could be more severely affected. Luckily, in the last years the COHERENT experiment has provided independent constraints on NSIs. This experiment measures neutral current coherent neutrino-nucleus elastic scattering, a low momentum transfer process quite sensitive to NSI induced by potentially light mediators. In the final chapter of the thesis, the data from the COHERENT experiment is analysed and integrated into the global analyses from previous chapters. Particular attention is paid to how the results depend on the assumptions about the experiment background, nuclear structure, and detector response. Combining COHERENT data with flavour transition experiments unveils its incipient role in increasing the robustness of their interpretation. These first results could be greatly improved by increasing the statistics of the signal and/or by performing the measurements with different nuclei sensitive to different NSI models. For that, the European Spallation Source is an ideal future facility. It will produce a neutrino beam one order of magnitude more intense than the one used at COHERENT, and as it is still under construction there is potential space for various modern detectors. Its prospects for bounding NSI are also explored. In summary, this thesis deals with the current experimental hint for large CP violation in the leptonic sector. It first quantifies its global significance, and then moves on to checking its robustness against the framework in which the experimental data is interpreted. For that, complementary experiments on neutrino-nucleus coherent scattering play, and will keep on playing in the future, a significant role. Thus, a global approach is taken to rigorously assess whether cutting-edge leptonic flavour measurements are pointing towards a new strong violation of a symmetry of Nature.[spa] A finales del siglo XX, una serie de experimentos que estudiaban neutrinos provenientes del Sol o de rayos cósmicos que colisionaban contra la atmósfera terrestre mostraron que estas partículas pueden cambiar su sabor, comportándose de una manera que el Modelo Estándar prohíbe explícitamente. El camino hacia la comprensión de las propiedades de los neutrinos, que podría revelar la siguiente estructura subyacente de la naturaleza, ha guiado desde entonces a miles de científicos. El escenario al inicio de esta tesis estaba impulsado por la última sorpresa experimental de los neutrinos: los primeros indicios que apuntan hacia su fuerte violación de la simetría materia-antimateria o CP. El objetivo de este trabajo es abordar el problema desde una perspectiva global para evaluar rigurosamente si las medidas punteras de física de sabor leptónico están apuntando hacia una nueva violación fuerte de una simetría de la naturaleza. Para ello, se combinan los resultados de todos los experimentos de neutrinos relevantes. Se evalúa cuantitativamente el estatus de la mezcla leptónica y de la violación de CP, que los datos apuntan a que podría ser máxima. Este indicio está dominado por un exceso de neutrinos electrónicos en el experimento de neutrinos con acelerador a larga distancia T2K. Dentro del paradigma de tres neutrinos masivos, y con el resto de parámetros de mezcla leptónica medidos con precisión en varios experimentos, el exceso solamente se puede acomodar mediante una violación de CP grande. A pesar de esto, tres neutrinos masivos es solamente una extensión mínima del Modelo Estándar: podría haber otra nueva física enmascarando los resultados, ya que la violación de CP leptónica aún no se ha medido de manera directa y concluyente. Por ello, esta tesis confronta la nueva física que podría afectar a los experimentos de transiciones de sabor de neutrinos con datos experimentales. La violación de CP inducida por las masas de los neutrinos y por la mezcla leptónica resulta ser bastante robusta. Tal y como se explora en este trabajo, los experimentos complementarios de interacción coherente entre neutrinos y núcleos juegan, y continuarán jugando en el futuro, un papel importante a este respecto

A Spatial Microsimulation Model for the Estimation of Heat Demand in Hamburg

Most spatial bottom up domestic heat models are based on an existing building stock data set, this can be the official digital cadastre (ALKIS in Germany), community based data sources (e.g: open-street) or collected data stored on a GIS system. On this paper we present an innovative method for the creation of spatial bottom up domestic heat models that do not need an existing building stock data-set as input. The advantage of this type of models are its transferability, speed and flexibility. The presented model uses national standardized statistical data, making it possible to apply it for any region in the country without having to modify the model. Because the input data for the model is more compact the speed of the model increases significantly, the type of analysis possible with a high speed model allow us to perform a microsimulation of the building stock for the entire country, see (Muñoz H., Seller, & Peters, 2015). The presented model structure allows us to quickly develop dynamic simulation scenarios. We present a spatial microsimulation model developed for the simulation of domestic heat demand. The presented model use the GREGWT R package to create a synthetic building stock benchmarked to aggregated small area statistics from the 2011 German census. We create this synthetic building stock from the 2010 microsensus. The heat estimation if performed on the microcensus with help of the heat R package. The simulation results present a monthly heat demand at a microlevel for the entire city of Hamburg. The generated data for the estimation of heat demand can be use as input data for other Agent Based Models. By enriching the microcensus with time use data, we are able to generate the basis data for the construction of activity based urban models. We see the development of this type of urban models as an essential development of urban planning, specially for a smart urban development. The generation of microdata is a fundamental part of the smart city development

Mathematical programming-based models for the distribution networks' decarbonization

(English) Climate change is pushing to decarbonize worldwide economies and forcing fossil fuel-based power systems to evolve into power systems based mainly on renewable energies sources (RES). Thus, increasing the energy generated from renewables in the energy supply mix involves transversal challenges at operational, market, political and social levels due to the stochasticity associated with these technologies and their capacity to generate energy at a small scale close to the consumption point. In this regard, the power generation uncertainty can be handled through battery storage systems (BSS) that have become competitive over the last few years due to a significant price reduction and are a potential alternative to mitigate the technical network problems associated with the intermittency of the renewables, providing flexibility to store/supply energy when is required. On the other hand, the capacity of low-cost generation from small-scale power systems (distributed or decentralized generation (DG)) represents an opportunity for both customers and the power system operators. i.e., customers can generate their energy, reduce their network dependency, and participate actively in eventual local energy markets (LEM), while the power system operator can reduce the system losses and increase the power system quality against unexpected external failures. Nevertheless, incorporating these structures and operational frameworks into distribution networks (DN) requires developing sophisticated tools to support decision-making related to the optimal integration of the distributed energy resources (DER) and assessing the performance of new DNs with high DERs penetration under different operational scenarios. This thesis addresses the distribution networks' decarbonization challenge by developing novel algorithms and applying different optimization techniques through three subtopics. The first axis addresses the optimal sizing and allocation of DG and BSS into a DN from deterministic and stochastic approaches, considering the technical network limitation, the electric vehicle (EV) presence, the users capacity to modify their load consumption, and the DG capability to generate reactive power for voltage stability. Besides, a novel algorithm is developed to solve the deterministic and stochastic models for multiple scenarios providing an accurate DERs capacity that should be installed to decrease the external network dependency. The second subtopic assesses the DN capacity to face unlikely scenarios like primary grid failure or natural disasters preventing the energy supply through a deterministic model that modifies the unbalance DN topology into multiple virtual microgrids (VM) balanced, considering the power supplied by DG and the flexibility provided by the storage devices (SD) and demand response (DR). The third axis addresses the emerging transactive energy (TE) schemes in DNs with high DERs penetration at a residential level through two stochastic approaches to model a Peer-to-peer (P2P) energy trading. To this end, the capability of a P2P energy trading scheme to operate on different markets as day-ahead, intraday, flexibility, and ancillary services (AS) market is assessed, while an algorithm is developed to manage the users' information under a decentralized design.(Català) El cambio climático está obligando a descarbonizar las economías de todo el mundo forzando a los sistemas de energía basados en combustibles fósiles a evolucionar hacia sistemas de energía basados principalmente en fuentes de energía renovables (FER). Así, incrementar la energía generada a partir de renovables en el mix energético está implicando retos transversales a nivel operativo, de mercado, político y social debido a la estocasticidad asociada a estas tecnologías y su capacidad de generar electricidad a pequeña escala cerca al punto de consumo. En este sentido, la incertidumbre en la generación de energía eléctrica puede ser manejada a través de sistemas de almacenamiento en baterías (BSS) que se han vuelto competitivos en los últimos años debido a una importante reducción de precios y son una potencial alternativa para mitigar los problemas técnicos de red asociados a la intermitencia de las renovables, proporcionando flexibilidad para almacenar/suministrar energía cuando sea necesario. Por otro lado, la capacidad de generación a bajo costo a partir de sistemas eléctricos de pequeña escala (generación distribuida o descentralizada (GD)) representa una oportunidad tanto para los clientes como para los operadores del sistema eléctrico. Es decir, los clientes pueden generar su energía, reducir su dependencia de la red y participar activamente en eventuales mercados locales de energía (MLE), mientras que el operador del sistema eléctrico puede reducir las pérdidas del sistema y aumentar la calidad del sistema eléctrico frente a fallas externas inesperadas. Sin embargo, incorporar estas estructuras y marcos operativos en las redes de distribución (RD) requiere desarrollar herramientas sofisticadas para apoyar la toma de decisiones relacionadas con la integración óptima de los recursos energéticos distribuidos (RED) y evaluar el desempeño de las nuevas RD con alta penetración de RED bajo diferentes escenarios de operación. Esta tesis aborda el desafío de la descarbonización de las redes de distribución mediante el desarrollo de algoritmos novedosos y la aplicación de diferentes técnicas de optimización a través de tres dimensiones. El primer eje aborda el dimensionamiento y localización óptimos de GD y BSS en una RD desde enfoques determinísticos y estocásticos, considerando la limitación técnica de la red, la presencia de vehículos eléctricos (VE), la capacidad de los usuarios para modificar su consumo de carga y la capacidad de GD para generar potencia reactiva para la estabilidad del voltaje. Además, se desarrolla un algoritmo novedoso para resolver los modelos determinísticos y estocásticos para múltiples escenarios proporcionando una capacidad precisa de RED que debe instalarse para disminuir la dependencia de la red externa. El segundo subtema evalúa la capacidad de la RD para enfrentar escenarios improbables como fallas en la red primaria o desastres naturales que impidan el suministro de energía, a través de un modelo determinista que modifica la topología de la RD desequilibrada en múltiples microrredes virtuales (MV) balanceadas, considerando la potencia suministrada por GD y la flexibilidad proporcionada por los dispositivos de almacenamiento y respuesta a la demanda (DR). El tercer eje aborda los esquemas emergentes de energía transactiva en RDs con alta penetración de RED a nivel residencial a través de dos enfoques estocásticos para modelar un comercio de energía Peer-to-peer (P2P). Para ello, se evalúa la capacidad de un esquema de comercialización de energía P2P para operar en diferentes mercados como el mercado diario, intradiario, de flexibilidad y de servicios complementarios, a la vez que se desarrolla un algoritmo para gestionar la información de los usuarios bajo un esquema descentralizado.Postprint (published version

Amalgam decomposition and cohomology of the group SL_2(Z) and the Bianchi groups

Este trabajo de grado contiene un par de ejemplos de cómo los grupos de cohomología de ciertos grupos de matrices se pueden calcular usando su descomposición como producto amalgamado y, la relación entre esos grupos y sus espacios clasificantes correspondientes. El documento está dividido en dos partes. La primera parte describe un método geométrico para probar que el grupo especial lineal SL_2(Z) es un producto amalgamado de grupos cíclicos, usando la acción del grupo sobre el plano hiperbólico. Luego, usamos esta descomposición y una sucesión exacta larga de Mayer-Vietoris para calcular los grupos de cohomología de este grupo. La segunda parte del trabajo de grado trata con grupos de Bianchi, que son definidos como PSL_2(O_d), donde O_d es el anillo de enteros de una extensión cuadrática imaginaria del cuerpo de los números racionales. La descomposición en amalgama de unos grupos particulares, los grupos de Bianchi Euclideanos, es dada, y concluimos con el cálculo de los grupos de cohomología del grupo Gamma_1=PSL_2(O_1).This thesis contains a couple of examples of how the cohomology groups of some groups of matrices can be computed using their decomposition as an amalgamated product and, the relation between those groups and their corresponding classifying spaces. The document is divided in two parts. The first part describes a geometric method to prove that the special linear group SL_2(Z) is an amalgamated product of cyclic groups, using the action of the group on the hyperbolic plane. Then, we use this decomposition and a Mayer-Vietoris long exact sequence to compute the cohomology groups of this group. The second part of the thesis deals with Bianchi groups, which are defined as PSL_2(O_d), where O_d is the ring of integers of an imaginary quadratic extension of the field of rational numbers. The amalgam decomposition of a particular groups, the Euclidean Bianchi groups, is given, and we conclude with the computation of the cohomology groups of the group Gamma_1=PSL_2(O_1).Matemático (a)Pregrad

Contributions by R Sennett to develop Business Ethics in the New Capitalism context

Este artículo tiene el objetivo de realizar una aproximación crítica al pensamiento de Richard Sennett con la mirada puesta en las aportaciones que su obra puede realizar al desarrollo de la Ética Empresarial. De ahí que el estudio busca reconocer las transformaciones que están produciéndose en el nivel organizativo, y que se traducen en la implementación de nuevas formas de producción y trabajo en el seno de las relaciones capitalistas, aspectos sumamente relevantes para ser capaces de orientar dichas relaciones en un sentido de justicia, prudencia y responsabilidad tal y como se plantea por la Ética Empresarial de corte discursivo.The objective of this article is to conduct a critical study of Richard Sennett’s thinking by focusing on the contributions his work can make to develop Business Ethics. This study aims to recognize the transformations that take place in organizational terms, and are then implemented into new forms of production and work at the heart of capitalist relations, which are extremely important aspects for guiding these relations in justice, prudence and responsibility terms, as it is proposed by discourse business ethics

Parliamentary information in regional parliaments in Spain: evaluation of web presence and social media sites

Desde la aparición de Internet y del World Wide Web los parlamentos han encontrado un cauce eficaz para llegar a los ciudadanos lo que se ha visto aumentado por la Web 2.0 y los nuevos medios sociales que han auspiciado una mayor comunicación con el exterior. Este trabajo presenta un estudio realizado a los parlamentos autonómicos españoles a través de la aplicación de dos recomendaciones de la Unión Interparlamentaria (UIP): las Directrices para sitios web parlamentarios y las Directrices para el uso de los medios sociales de comunicación por los parlamentos. El estudio se ha llevado a cabo a través de un cuestionario basado en dichas recomendaciones y los datos se han extraído por observación en las páginas web.Since the advent of the Internet and the World Wide Web, parliaments have found them to be an effective channel through which to reach citizens. This has been enhanced by the so-called Web 2.0 with its new social media that have facilitated more communication with the outside. This paper presents a study applied to Spain's Autonomous Community (regional) parliaments with the implementation of two recommendations of the Inter-Parliamentary Union (IPU): Guidelines for Parliamentary Websites, and Guidelines for the Use of Social Communication Media by Parliaments. The study instrument was a questionnaire based on these recommendations, and by observation of all the corresponding Web pages