Nesta tese, realizamos dois tipos de estudos fenomenológicos através de uma análise detalhada de alguns experimentos terrestres atuais e futuros. No primeiro, estudamos dois mecanismos exóticos de conversão de sabor: descoerência quântica e interações não padrão do neutrino com a matéria. Para descoerência, vinculamos o parâmetro de descoerência bem como testamos como distinguir a solução de descoerência pura do mecanismo padrão de oscilação no contexto de duas gerações. No caso das interações não padrão, assumimos que esta é subdominante frente ao mecanismo de oscilação padrão, e encontramos os possíveis limites que poderão ser obtidos para essas interações utilizando uma fábrica de neutrinos futura. No segundo tipo de estudo, determinamos os parâmetros de oscilação solares pela análise combinada dos dados dos neutrinos solares e de KamLAND, e estimamos a precisão nos parâmetros de mistura atmosféricos que poderá ser atingida pelos experimentos de LongBaseLine futuros MINOS, ICARUS e OPERA. Por fim, investigamos a possibilidade dos experimentos futuros do duplo decaimento sem neutrinos de determinar os parâmetros de não oscilação. / In this thesis, we have done two kind of phenomenological studies through a detailed analysis of present and future terrestrial experiments. In the first study, we analyze two exotic mechanisms of flavour conversion: quantum decoherence and non-standard neutrino-matter interactions. In the case of decoherence, we impose constraints on the decoherence parameter and test how to distinguish between the pure decoherence solution and the standard neutrino ascillation mechanism in the contexto f two neutrino generations. For non-standard interactions, assuming it as a sub-leading process compared to the standard oscillation, we find the possible limits that can be achieved on the strength of these interactions using a future neutrino factory. In the second part of the study, we determine the solar oscillation parameters using a combined analysis of solar neutrino and KamLAND data, and estimate the precision on the atmospheric mixing parameters by that can be accomplished by the LongBaseline experiments MINOS, ICARUS and OPERA. Finally, we investigate the capability of future neutrinoless Double beta decay experiments to determine the non-oscillation parameters.

L’expérience SuperNEMO est conçue pour la recherche de la double désintégration bêta (ββ) sans émission de neutrinos impliquant un neutrino de Majorana (ν ≡ ν̄) massif. Le module démonstrateur de l’expérience est actuellement en cours d’installation au Laboratoire Souterrain de Modane (LSM). La technique de détection utilisée, dite tracko-calo, permet la mesure en énergie des particules traversant le détecteur ainsi qu’une reconstruction complète de leur cinématique.Cette thèse présente la conception, la simulation et l’implémentation d’un système de déclenchement de l’électronique pour le module démonstrateur de SuperNEMO. Le but de ce système est de maximiser l’efficacité de détection pour des évènements ββ ainsi que pour des évènements dits de bruits de fond issus de la radioactivité naturelle tout en réduisant le taux d’acquisition pour des évènements d’autodéclenchement des détecteurs. Un ensemble d’algorithmes de reconnaissances de traces et d’association calorimètre–trajectographe a été développé et implémenté dans les cartes électroniques après validation par des simulations Monte-Carlo. Les objectifs de performance ont été atteints en prenant en compte les différentes contraintes (physique des détecteurs, électronique, temps réel) maximisant les efficacités de détection pour des évènements d’intérêt physique. / The SuperNEMO experiment is designed for the neutrinoless double beta decay (ββ) research involving a massive Majorana neutrino (ν ≡ ν̄). The demonstrator module of the experiment is currently being installed at the Laboratoire Souterrain de Modane (LSM). The so-called tracko-calo detection technique allows the energy measurement of the particles passing through the detector and a complete reconstruction of their kinematics.This thesis presents the design, simulation and implementation of the electronics trigger system for the SuperNEMO demonstrator module. The purpose of this system is to maximize the detection efficiency for ββ events as well as for background events due to natural radioactivity while reducing the acquisition rate caused by spurious events. Pattern recognition and calorimeter-tracker association algorithms have been developed and implemented in electronic boards after validation by Monte-Carlo simulations. The performance targets have been reached, taking into account different constraints (physics of the detectors, electronics, real time) with maximized detection efficiency for events of interest.

The CNO cycle consists of a set of nuclear reactions that convert hydrogen into helium and releases energy in stars. The cycle contributes less than 1% to our Sun's luminosity, but it is responsible for detectable neutrino fluxes that can bring direct information of the physical conditions in the solar core, provided that the nuclear reaction rate is known with sufficient precision. The 14N(p,γ)15O is the slowest reaction in the CNO cycle and estabilishes its rate. The experimental study has been performed both at the LUNA 400 kV accelerator deep underground in the Gran Sasso mountain in Italy and at a 3 MV Tandetron in the Helmholtz-Zentrum Dresden-Rossendorf. A proton beam was sent on solid TiN targets and the prompt photons were collected by a composite HPGe detector (at LUNA) or by up to four HPGe detectors (Dresden). The obtained results improve the fit of the excitation function in the R-matrix framework, that is used to extrapolate the S-factor at the very low astrophysical energies. In addition, the strength of two resonances at Ep = 430 and 897 keV of the 15N(p,αγ)12C reaction were measured, improving the precision for hydrogen depth profiling.

Experiments on neutrino oscillations have confirmed that neutrinos have small, but non-zero masses, and that the interacting neutrino states do not have definite masses, but are mixtures of such states.The seesaw models make up a group of popular models describing the small neutrino masses and the corresponding mixing.In these models, new, heavy fields are introduced and the neutrino masses are suppressed by the ratio between the electroweak scale and the large masses of the new fields. Usually, the new fields introduced have masses far above the electroweak scale, outside the reach of any foreseeable experiments, making these versions of seesaw models essentially untestable. However, there are also so-called low-scale seesaw models, where the new particles have masses above the electroweak scale, but within the reach of future experiments, such as the LHC.In quantum field theories, quantum corrections generally introduce an energy-scale dependence on all their parameters, described by the renormalization group equations. In this thesis, the energy-scale dependence of the neutrino parameters in two low-scale seesaw models, the low-scale type I and inverse seesaw models, are considered. Also, the question of whether the neutrinos are Majorana particles, \ie , their own antiparticles, has not been decided experimentally. Future experiments on neutrinoless double beta decay could confirm the Majorana nature of neutrinos. However, there could also be additional contributions to the decay, which are not directly related to neutrino masses. We have investigated the possible future bounds on the strength of such additional contributions to neutrinoless double beta decay, depending on the outcome of ongoing and planned experiments related to neutrino masses. / QC 20110812

Neutrino astronomy is expanding into the ultra-high energy (>1017eV) frontier with the use of in-ice detection of Askaryan radio emission from neutrino-induced particle showers. There are already pilot arrays for validating the technology and the next few years will see the planning and construction of IceCube-Gen2, an upgrade to the current neutrino telescope IceCube. This thesis aims to facilitate that planning by providing faster simulations using deep learning surrogate models. Faster simulations could enable proper optimisation of the antenna stations providing better sensitivity and reconstruction of neutrino properties. The surrogates are made for two parts of the end-to-end simulations: the signal generation and the signal propagation. These two steps are the most time-consuming parts of the simulations. The signal propagation is modelled with a standard fully connected neural network whereas for the signal generation a conditional Wasserstein generative adversarial network is used. There are multiple reasons for using these types of models. For both problems the neural networks provide the speed necessary as well as being differentiable -both important factors for optimisation. Generative adversarial networks are used in the signal generation because of the inherent stochasticity in the particle shower development that leads to the Askaryan radio signal. A more standard neural network is used for the signal propagation as it is a regression task. Promising results are obtained for both tasks. The signal propagation surrogate model can predict the parameters of interest at the desired accuracy, except for the travel time which needs further optimisation to reduce the uncertainty from 0.5 ns to 0.1 ns. The signal generation surrogate model predicts the Askaryan emission well for the limited parameter space of hadronic showers and within 5° of the Cherenkov cone. The two models provide a first step and a proof of concept. It is believed that the models can reach the required accuracies with more work.

In recent years, there has been a large interest in the subject of extra dimensions in particle physics. In particular, a number of models have been suggested which provide solutions to some of the problems with the current Standard Model of particle physics, and which could be tested in the next generation of high-energy experiments. Among the most important of these models are the large extra dimensions model by Arkani-Hamed, Dimopoulos, and Dvali, the universal extra dimensions model, and models allowing right-handed neutrinos to propagate in the extra dimensions. In this thesis, we study phenomenological aspects of these three models, or simple modifications of them.   The Arkani-Hamed-Dimopoulos-Dvali model attempts to solve the gauge hierarchy problem through a volume suppression of Newton's gravitational constant, lowering the fundamental Planck scale down to the electroweak scale. However, this solution is unsatisfactory in the sense that it introduces a new scale through the radius of the extra dimensions, which is unnaturally large compared to the electroweak scale. It has been suggested that a similar model, with a hyperbolic internal space, could provide a more satisfactory solution to the problem, and we consider the hadron collider phenomenology of such a model.   One of the main features of the universal extra dimensions model is the existence of a potential dark matter candidate, the lightest Kaluza-Klein particle. In the so-called minimal universal extra dimensions model, the identity of this particle is well defined, but in more general models, it could change. We consider the indirect neutrino detection signals for a number of different such dark matter candidates, in a five- as well as a six-dimensional model.   Finally, right-handed neutrinos propagating in extra dimensions could provide an alternative scenario to the seesaw mechanism for generating small masses for the left-handed neutrinos. Since extra-dimensional models are non-renormalizable, the Kaluza-Klein tower is expected to be cut off at some high-energy scale. We study a model where a Majorana neutrino at this cutoff scale is responsible for the generation of the light neutrino masses, while the lower modes of the tower could possibly be observed in the Large Hadron Collider. We investigate the bounds on the model from non-unitarity effects, as well as collider signatures of the model. / QC 20110324

Title: Electroweak symmetry breaking by dynamically generated masses of quarks and leptons Author: Adam Smetana Department: Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University Supervisor: Ing. Jiří Hošek, DrSc., Department of Theoretical Physics, Nuclear Physics Institute, Academy of Sciences of the Czech Republic Abstract: The aim of the thesis is to study models of the electroweak symmetry breaking caused by dynamically generated masses of quarks and lep- tons. (1) We perform the basic analysis whether the main underlying idea, that the masses of only known fermions can provide the elec- troweak symmetry breaking, is actually feasible. For that we elaborate a two-composite-Higgs-doublet model of the top-quark and neutrino condensation. The model suggests rather large number, O(100), of right-handed neutrinos. (2) We analyze the model of strong Yukawa dynamics where the dynamical fermion mass generation is provided by exchanges of new elementary massive complex doublet scalar fields. We focus on solving the coupled Schwinger-Dyson equations for fermion and scalar self-energies by means of approximative methods. We doc- ument that strongly hierarchical mass spectra can be reproduced. (3) We elaborate the flavor gauge model where the dynamical fermion mass...

Tesis por compendio / Neutrino telescopes are a new way of looking at the Universe. For more than a decade these structures are being designed to study the Universe from a new point of view, that is, from the particles generated in the cosmic accelerators of particles. These infrastructures are not only useful to study the Universe, but they can also be used in the field of Particle Physics and even in the study of underwater life. Most of these telescopes are based on the detection of the so-called Cherenkov light using photomultipliers, the difference between them lies in the medium in which they are located (ice or water) and in the infrastructure used. Specifically, European telescopes mount these photomultipliers in an underwater vertical structure anchored at great depth, which is under the influence of sea currents. For this reason they suffer displacements that affect the location of the photomultipliers and it becomes necessary to implement a positioning system for the telescope to be functional. For this, an acoustic system consisting of emitters anchored to the sea floor and receivers located at the different levels of the vertical structure is used. One of the objectives of the present thesis is the development of these acoustic emitters. For this purpose we have developed different laboratory prototypes with different features until obtaining an improved prototype that was installed and tested in ANTARES and NEMO telescopes. This showed that the prototype worked perfectly within the established requirements and then, we proceed to design a final version of the much more powerful and functional emitter, acoustic beacon, to be mounted inside aluminum vessels together with an omnidirectional acoustic transducer, which will be located in anchored positions of the new KM3NeT neutrino telescope. In collaboration with the MSM Company, 18 acoustic beacons were developed for KM3NeT-ARCA being two of them installed in the first marine campaign at the end of 2015, and being able then to verify their correct operation. On the other hand, interaction of ultraenergetic neutrinos with matter also produces a thermoacoustic pulse with bipolar form, axial symmetry and highly directive. The feasibility of the acoustic detection technique and the possibility of implementing it in these telescopes have been under study for years. In order to test and calibrate this technique, it is necessary to have an acoustic emitter system able of generating a signal similar to the neutrino signature. This has been the second objective developed in this thesis. To achieve this objective, a compact and versatile calibrator based on an array of acoustic transducers using parametric generation has been designed. Given the complexity of the pulse to emulate and the novelty of the technique to be used, it has been necessary to carry out different laboratory tests in order to obtain suitable transducers and electronics able of making them to work at the required power and efficiency. The positive results obtained in this line suggest that we will be able to obtain a full functional neutrino acoustic calibrator soon. Finally, I would like to mention that I have participated in the different research and activities described in the thesis, putting especial emphasis in the development of the electronics and the software/firmware of the developed acoustic emitters. / Los telescopios de neutrinos son una nueva forma de observar el Universo. Desde hace más de una década se están diseñando este tipo de estructuras con el propósito de estudiar el Universo desde un nuevo punto de vista, el de las partículas que se generan en los aceleradores de partículas cósmicos. Estas infraestructuras no solo se limitan al estudio del Universo, sino que también pueden ser utilizadas en el campo de la Física de partículas e incluso en el estudio de la vida submarina. La mayoría de estos telescopios se basan en la detección de la llamada luz de Cherenkov mediante fotomultiplicadores, la diferencia entre ellos radica en el medio en que se ubican (hielo o agua) y en la infraestructura utilizada. Concretamente, los telescopios europeos montan dichos fotomultiplicadores en una estructura vertical submarina anclada a gran profundidad, la cual está sometida a la influencia de las corrientes marinas. Por este motivo sufren desplazamientos que afectan a la localización de los fotomultiplicadores y se hace necesaria la implementación de un sistema de posicionamiento para que el telescopio sea funcional. Para ello se utiliza un sistema acústico consistente en unos emisores anclados al suelo marino y unos receptores situados en los diferentes niveles de la estructura vertical. Uno de los objetivos de la presente tesis es el desarrollo de estos emisores acústicos. Con este fin se han desarrollado diferentes prototipos de laboratorio con los que se han ido escalando prestaciones hasta obtener un prototipo que ha sido instalado y testeado en los telescopios ANTARES y NEMO. Así se demostró que el prototipo funcionaba perfectamente dentro de los requisitos establecidos, pasándose a diseñar una versión final del emisor acústico mucho más potente y funcional para ser montada dentro de vasijas de aluminio junto con un traductor omnidireccional en las anclas del nuevo telescopio de neutrinos KM3NeT. Conjuntamente con la empresa MSM se elaboraron 18 equipos para KM3NeT-ARCA, dos de los cuales fueron instalados en la primera campaña marina a finales de 2015 comprobándose su correcto funcionamiento. Por otro lado, la interacción de los neutrinos ultraenergéticos con la materia también produce un pulso termoacústico con forma bipolar, simetría axial y altamente directivo. Desde hace años se está estudiando la viabilidad de la técnica de detección acústica y la posibilidad de implementarla en dichos telescopios. Para poder poner a prueba y calibrar dicha técnica es necesario disponer de un sistema emisor acústico que sea capaz de generar una señal similar a la descrita. Este ha sido el segundo objetivo desarrollado en esta tesis. Para ello se ha diseñado un calibrador compacto y versátil basado en un array de transductores acústicos usando generación paramétrica. Dada la complejidad del pulso a emular y lo novedoso de la técnica a utilizar, se ha requerido la realización de numerosas pruebas de laboratorio con el fin de conseguir unos transductores adecuados y la electrónica capaz de hacerlos funcionar a la potencia y eficiencia requerida. Los positivos resultados obtenidos en esta línea hacen prever que, en breve, podremos obtener un calibrador acústico de neutrinos funcional. Finalmente, cabe reseñar que he participado en las diferentes investigaciones y actividades que se describen en la tesis, siendo mi cometido principal el desarrollo tanto de la electrónica como de los diferentes softwares/firmwares implicados en los emisores acústicos desarrollados. / Els telescopis de neutrins són una nova forma d'observar l'Univers. Des de fa més d'una dècada s'estan dissenyant aquest tipus d'estructures amb el propòsit d'estudiar l'Univers des d'un nou punt de vista, el de les partícules que es generen en els acceleradors de partícules còsmics. Estes infraestructures no sols es limiten a l'estudi de l'Univers, sinó que també poden ser utilitzades en el camp de la Física de partícules i fins i tot en l'estudi de la vida submarina. La majoria d'aquests telescopis es basen en la detecció de l'anomenada llum de Cherenkov per mitjà de fotomultiplicadors, la diferència entre ells radica en el mig en què s'ubiquen (gel o aigua) i en la infraestructura utilitzada. Concretament, els telescopis europeus munten dits fotomultiplicadors en una estructura vertical submarina ancorada a gran profunditat, la qual està sotmesa a la influència dels corrents marins. Per este motiu pateixen desplaçaments que afecten a la localització dels fotomultiplicadors i es fa necessària la implementació d'un sistema de posicionament per a què el telescopi siga funcional. Per a això s'utilitza un sistema acústic consistent en uns emissors ancorats al sòl marí i uns receptors situats en els diferents nivells de l'estructura vertical. Un dels objectius de la present tesi és el desenvolupament d'aquests emissors acústics. Amb este fi s'han desenvolupat diferents prototips de laboratori amb els quals s'han anat escalant prestacions fins a obtindre un prototip que ha sigut instal·lat i testeat en els telescopis ANTARES i NEMO. Així es va demostrar que el prototip funcionava perfectament dins dels requisits establerts, passant-se a dissenyar una versió final de l'emissor acústic molt més potent i funcional per a ser muntada dins d'atuells d'alumini junt amb un traductor omnidireccional en les àncores del nou telescopi de neutrins KM3NeT. Conjuntament amb l'empresa MSM es van elaborar 18 equips per a KM3NeT-ARCA, dos dels quals van ser instal·lats en la primera campanya marina a finals de 2015 comprovant-se el seu correcte funcionament. D'altra banda, la interacció dels neutrins ultraenergètics amb la matèria també produeix un pols termoacústic amb forma bipolar, simetria axial i altament directiu. Des de fa anys s'està estudiant la viabilitat de la tècnica de detecció acústica i la possibilitat d'implementar-la en els esmentats telescopis. Per a poder posar a prova i calibrar esta tècnica és necessari disposar d'un sistema emissor acústic que siga capaç de generar un senyal semblant al descrit. Aquest ha sigut el segon objectiu desenvolupat en aquesta tesi. Per a això s'ha dissenyat un calibrador compacte i versàtil basat en un array de transductores acústics utilitzant generació paramètrica. Donada la complexitat del pols a emular i la novetat de la tècnica a utilitzar, s'ha requerit la realització de nombroses proves de laboratori a fi d'aconseguir uns transductors adequats i l'electrònica capaç de fer-los funcionar a la potència i eficiència requerida. Els positius resultats obtinguts en esta línia fan preveure que, en breu, podrem obtindre un calibrador acústic de neutrins funcional. Finalment, cal ressenyar que he participat en les diferents investigacions i activitats que es descriuen en la tesi, sent la meua comesa principal el desenvolupament tant de l'electrònica com dels diferents softwares/firmwares implicats en els emissors acústics desenvolupats. / Llorens Alvarez, CD. (2017). Diseño y desarrollo de la electrónica de los emisores acústicos para los sistemas de posicionamiento y calibración de telescopios submarinos de neutrinos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/88401 / Compendio

Neutrino oscillations est trés bien étudié le phénoméne et des observations de Solar, trés-long-base de référence du réacteur, l'atmosphére et d'accélérateur à l'oscillation des neutrinos expériences trés robuste donner la preuve de trois mélange des neutrinos. D'autre part, certaines données expérimentales ont montré des anomalies qui pourraient être interprétées comme indication de la physique des neutrinos exotique au-delà de trois mélange des neutrinos. En outre, à partir d'un point de vue cosmologiques, la possibilité déspéces extra léger comme une contribution subdominant chaud de l'Univers est toujours intéressant. Dans la premiére partie de cette thése, nous nous sommes concentrs sur l'anomalie observée dans le Gallium source radioactive expériences. Ces expériences ont été réalisées pour tester la Gallium détecteurs de neutrinos solaires GALLEX et SAGE, en mesurant le flux de neutrinos d'électrons produit par une intense des sources radioactives artificielles placées à l'intérieur de détecteurs. Le mesurée certain nombre d'événements a été inférieur à celui attendu. Nous avons interprété cette anomalie comme une indication possible de la disparition de neutrinos et d'électrons, dans le cadre efficace de deux de mélange des neutrinos, nous avons obtenu sin2 2Theta > 0.03 et Deltam2 > 0.1 eV2. Nous avons également étudié la compatibilité de ce rsultat avec les donnes de le réacteur Bugey et de Chooz antineutrino disparition expériences. Nous avons constaté que les données Bugey présente un indice d'oscillations de neutrinos 'a 0.02 < sin2 2Theta < 0.07 et Deltam2 ≈ 1.95 eV2, qui est compatible avec le permis de Gallium de la region paramtres de mixage. Puis, en combinant les données de Bugey et de Chooz, les données de Gallium et de Bugey, et les données de Gallium, le Bugey et de Chooz, nous avons constaté que ce soup¸con persiste, avec une certaine compatibilité des données expérimentales. En outre, nous avons analysé les données expérimentales de l'ILL, SRS, Gösgen et expériences réacteur nucléaire. Nous avons obtenu un bon ajustement de la I.L.L. données, en montrant 1 et 2Sigma permis régions de l'espace des paramétres d'oscillation. Toutefois, la combinaison de I.L.L. données avec le Bugey les données ont révélé un trés faible compatibilité, si nous n'avons pas utilisé l'ILL données pour les analyzes supplémentaires. Notre ajustement de la S.R.S. expérience a donn de trés petites valeurs de la qualité d'ajustement (goodness-of-fit), ce qui indique que les données sont incompatibles avec l'hypothése d'oscillations, ainsi que les oscillations aucune hypothése. Nous n'avons pas d'explication à ce résultat. De l'analyze de la Gösgen expérience, nous avons obtenu des limites supérieures pour les paramétres de mélange, à l'exclusion de la region avec sin2 2Theta ≥ 0.3 et Deltam ≥ 0.05 eV2 à 3Sigma C.L.. Grâce â la combinaison de ces données avec celles de Gallium, le Bugey et de Chooz, nous avons constaté que l'indice des oscillations de neutrinos persiste â 0.03 < sin2 2Theta < 0.07 et Deltam2 ≈ 1.93 eV2, avec une bonne compatibilité des données. Toutefois, les oscillations aucune hypothése ne peut être exclue. Motivé par ces résultats, dans la deuxiéme partie de ce travail nous avons étudié contraintes cosmologiques sur une lumiére non-thermique neutrino stérile. Nous aménagées--la date des données cosmologiques avec une longue LCDM, y compris en lumiére les vestiges d'une masse dans la gamme 0.1-10 eV. Nous avons obtenu des contraintes sur la densité de courant et de la vitesse de dispersion de ces reliques, ainsi que des contraintes sur leur masse, à supposer qu'elles consistent soit découplé de la petite thermique des reliques, ou de non-resonantly produit stérile neutrinos. Nos résultats sont utiles pour peser sur des particules-motivés avec trois modéles de neutrinos actifs et un trés léger espéces.

The discovery of the Higgs boson by the LHC provided the last piece of the puzzle neces- sary for the Standard Model (SM) to be a successful theory of electroweak scale physics. However there exist various phenomenological reasons which serve as pointer towards the existence of physics beyond the Standard Model. For example the explanation for the smallness of the neutrino mass, baryon asymmetry of the universe, the presence of dark matter and dark energy etc. are not within purview of the Standard Model. Con- ceptual issues like the gauge hierarchy problem, weakness of gravity provide some of the theoretical motivation to pursue theories beyond the SM. We consider scenarios with warped extra-dimensions (Randall-Sundrum (RS) Model ) as our preferred candidate to answer some of the questions raised above. RS model gives an elegant geometric solution to address the hierarchy between the two fundamental scales of nature i.e. Planck scale and electroweak scale. In addition to this, the geometry of RS serves as a useful setup wherein the fermion mass hierarchy problem can also be solved. The goal of this thesis is to investigate whether RS model can be an acceptable theory of avour while at the same time serving as a solution to the hierarchy problem. In Chapter[1] we begin with a brief introduction of the SM, highlighting issues which pro- vides the necessary motivation for constructing new physics models. Various candidates of Beyond Standard Model (BSM) physics are introduced and a few preliminaries es- sential to understand frameworks with additional spatial-dimensions ( at and warped) is provided. In Chapter[2] we specialize to the case of warped extra-dimensions and motivate the need to have the SM elds in the bulk. Mathematical details related to the analysis of various spin elds (0; 12; 1 and 2) in a warped background necessary to understand relevant phenomenology is provided. The lack of knowledge of Dirac or Majorana nature of the neutrino leads to a wide variety of possibilities as far as neutrino mass generation is concerned. In Chapter[3] we focus on the leptonic sector where three cases of neutrino mass generation are consid- ered: a)Planck Scale lepton number violation (LLHH case) b) Dirac neutrinos c) Bulk Majorana mass terms. We then study the implications of each case on the charged lepton mass tting. The case with Planck scale lepton number violation in normal RS scenario requires large and negative values for the bulk mass parameters for the charged singlets cE. Dirac neutrinos and the case with Bulk Majorana mass terms give good t to data. For completeness, the ts for the hadronic sector is provided in the appendix. In Chapter[4] avour violation for each of three cases introduced in Chapter[3] is studied. For the case with Planck scale lepton number violation, the non-perturbative Yukawa coupling between the SM singlets and the KK states render the higher order diagrams incalculable. Lepton avour violation (LFV) is particularly large for the Dirac case and the bulk Majorana case for low Kaluza-Klein(KK) mass scales. We then invoke the ansatz of Minimal Flavour violation to suppress LFV with low lying KK scales and examples of avour group is provided for both cases. In Chapter[5] we present an example with a type II two Higgs doublet model applied to the LLHH case. The setup o ers a solution where LLHH scenario can be consistently realized in RS model, where the masses and mixing angles in the leptonic sector can bet with O(1) choice of bulk parameters. Assumption of global lepton number conservation (like in Dirac neutrinos) could lead to problems in theories of quantum gravity where it does not hold. This leads us to the question whether Dirac neutrinos can be naturally realized in nature. In Chapter[6] we consider the special case of bulk Majorana mass encountered in Chapter[3] where the bulk Dirac mass terms for the right handed neutrino is set to zero. We nd that this leads to a case where the e ective zero mode neutrino mass is of Dirac type with negligible e ects from the tower of Majorana states. In Chapter[7] we consider RS at the GUT scale which no longer serves as a solution to the hierarchy problem. SUSY is introduced in the bulk and the low energy SUSY serves as a solution to the hierarchy problem. Such models serve as a useful alternative to SUSY models with family symmetries (e.g. Froggatt-Nielsen Model). However the solutions to the Yukawa hierarchy problem are constrained due to anomaly cancellation conditions. In Chapter[8] supersymmetry breaking due to radion mediation in addition to brane localized sources is considered and detailed analysis of the running of soft masses and the low energy avour observables is considered for both cases separately. In Chapter[9] we conclude and present future directions.