Constraints on coloured scalars from global fits

We consider a simple extension of the electroweak theory, incorporating one $SU(2)_L$ doublet of colour-octet scalars with Yukawa couplings satisfying the principle of minimal flavour violation. Using the HEPfit package, we perform a global fit to the available data, including all relevant theoretical constraints, and extract the current bounds on the model parameters. Coloured scalars with masses below 1.05 TeV are already excluded, provided they are not fermiophobic. The mass splittings among the different (charged and CP-even and CP-odd neutral) scalars are restricted to be smaller than 20 GeV. Moreover, for scalar masses smaller than 1.5 TeV, the Yukawa coupling of the coloured scalar multiplet to the top quark cannot exceed the one of the SM Higgs doublet by more than 80%. These conclusions are quite generic and apply in more general frameworks (without fine tunings). The theoretical requirements of perturbative unitarity and vacuum stability enforce relevant constraints on the quartic scalar potential parameters that are not yet experimentally tested

Updated global fit of the ATHDM with heavy scalars

An updated global fit on the parameter-space of the Aligned Two-Higgs-Doublet model has been performed with the help of the open-source package \texttt{HEPfit}, assuming the Standard-Model Higgs to be the lightest scalar. No new sources of CP violation, other than the phase in the CKM matrix of the Standard Model, have been considered. A similar global fit was previously performed in Ref. \cite{Eberhardt:2020dat} with a slightly different set of parameters. Our updated fit incorporates improved analyses of the theoretical constraints required for positivity of the scalar potential and perturbative unitarity, additional flavour observables and updated data on direct searches of heavy scalars at the LHC, Higgs signal strengths and electroweak precision observables. Although not included in the main fit, the implications of the CDF measurement of the $W^\pm$ mass are also discussed.Comment: 41 pages, 15 figure

Global fit of the Aligned Two-Higgs-Doublet Model

Though the Standard Model (SM) provides a very elegant description of the interactions among fundamental particles, there are ample evidences suggesting that new physics is needed. In particular, extending the scalar sector has enough motivation from vacuum stability, electroweak phase transition and various other sectors. Among different such extensions, the two-Higgs-doublet model (THDM) is the simplest one that preserves the electroweak $\rho$ parameter. Flavour-changing neutral currents (FCNC) are usually avoided by implementing additional discrete symmetries, but this type of models are subject to severe phenomenological constraints. In the more general framework of the aligned THDM (ATHDM) tree-level FCNCs are avoided by choosing the same flavour structure for the Yukawa couplings of the two scalar doublets, which results in weaker phenomenological constraints. Here, we present a global fit of the ATHDM, using the package HEPfit that performs a bayesian analysis on the parameter-space of this model with the help of stability and perturbativity bounds, experimental data for various flavour and electroweak precision observables, and constraints from Higgs searches at the LHC. This global fit has been performed assuming that all additional scalars are heavier than the SM Higgs and that there are no extra sources of CP violation beyond the CKM phase.Comment: 6 pages, Contribution to EPS-HEP2023 (21-25 August, 2023, Hamburg, Germany

Proyecto de implementación de sondas de medición de amonio y nitratos en Dosim S.L.

Dins la indústria química, al sector dedicat al tractament d'aigües, calen bons equips de mesurament i dosificació per poder mantenir alguns paràmetres o compostos químics que es troben diluïts en aquestes aigües, dins de les normatives que té cadascuna d'elles depenent de l'aplicació que tingueu. Alguns d'aquests compostos químics o paràmetres poden ser: el clor, el brom, l'oxigen dissolt, el pH, la terbolesa, el potencial redox, l'amoni, el nitrat... i precisament en la detecció d'aquests dos darrers en aigua (l'amoni i el nitrat) és del que tracta aquest projecte. Ja que un excés dels nivells d'amoni i nitrat poden ocasionar efectes perjudicials per a la salut humana o per al medi ambient, gràcies a l'empresa DOSIM SLU, es va decidir iniciar aquest projecte per aconseguir implementar a l'empresa sondes de detecció i mesurament d'amoni i nitrats en aigües perquè, a banda d'oferir als clients sondes per al mesurament de pH, clor, brom, oxigen dissolt i altres paràmetres com ja fan, també se'ls pugui oferir un producte dedicat a la detecció i mesurament d'amonis i nitrats. Per això, s'ha dut a terme una tasca de cerca d'informació sobre aquests ions, per conèixer-ne més i saber els diferents mètodes que s'utilitzen a hores d'ara per a la seva detecció dins del sector de tractament d'aigües. Un cop coneguda aquesta informació, s'ha descartat la idea de fabricar a la mateixa empresa aquest producte i s'ha optat per l'opció d'implementar el producte desitjat mitjançant un proveïdor que subministrés aquest producte a l'empresa. D'aquesta manera, s'ha realitzat un estudi de mercat per intentar aconseguir l'objectiu d'implementar aquest producte a l'empresa i entrar al mercat com a possible competència respecte d'altres empreses del sector.Dentro de la industria química, en el sector dedicado al tratamiento de aguas, se precisa de buenos equipos de medición y dosificación para poder mantener algunos parámetros o compuestos químicos que se encuentran diluidos en esas aguas, dentro de las normativas que tiene cada una de ellas dependiendo de la aplicación que vayan a tener. Algunos de esos compuestos químicos o parámetros pueden ser: el cloro, el bromo, el oxígeno disuelto, el pH, la turbidez, el potencial redox, el amonio, el nitrato… y precisamente en la detección de estos dos últimos en agua (el amonio y el nitrato) es de lo que trata el presente proyecto. Ya que un exceso de los niveles de amonio y nitrato pueden ocasionar efectos perjudiciales para la salud humana o para el medio ambiente, gracias a la empresa DOSIM S.L.U, se decidió iniciar este proyecto para conseguir implementar en la empresa sondas de detección y medición de amonio y nitratos en aguas para que, a parte de ofrecer a los clientes sondas para la medición de pH, cloro, bromo, oxigeno disuelto y otros parámetros como ya hacen, también se les pueda ofrecer un producto dedicado a la detección y medición de amonios y nitratos. Por ello, se ha realizado una tarea de búsqueda de información sobre estos iones, para conocer más sobre ellos y saber los distintos métodos que se utilizan a día de hoy para su detección dentro del sector de tratamiento de aguas. Una vez conocida dicha información, se ha descartado la idea de fabricar en la propia empresa ese producto y, se ha optado por la opción de implementar el producto deseado mediante un proveedor que le suministrara dicho producto a la empresa. De esa forma, se ha realizado un estudio de mercado para intentar conseguir el objetivo de implementar ese producto en la empresa y, entrar al mercado como posible competencia respecto a otras empresas del sector.Within the chemical industry, in the sector dedicated to water treatment, good measuring and dosing equipment is needed to be able to maintain some parameters or chemical compounds that are diluted in these waters, within the regulations that each of them has. depending on the application they are going to have. Some of these chemical compounds or parameters can be: chlorine, bromine, dissolved oxygen, pH, turbidity, redox potential, ammonium, nitrate... and precisely in the detection of these last two in water (ammonium and nitrate) is what this project is about. Since an excess of ammonium and nitrate levels can cause harmful effects to human health or the environment, thanks to the company DOSIM SLU, it was decided to start this project to implement ammonium detection and measurement probes in the company and nitrates in water so that, apart from offering customers probes for the measurement of pH, chlorine, bromine, dissolved oxygen and other parameters as they already do, they can also be offered a product dedicated to the detection and measurement of ammonia and nitrates. For this reason, an information search task has been carried out on these ions, to learn more about them and to know the different methods that are used today for their detection within the water treatment sector. Once this information is known, the idea of manufacturing that product in the company itself has been ruled out and the option of implementing the desired product through a supplier that would supply said product to the company has been chosen. In this way, a market study has been carried out to try to achieve the objective of implementing this product in the company and enter the market as a possible competition with respect to other companies in the sector.Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejamen

Arquitecturas avanzadas distribuidas escalables e inteligentes

Treball Final de Grau en Enginyeria Informàtica. Codi: EI1054. Curs: 2015/2016Este documento contiene la memoria del trabajo de fin de máster del Máster Universitario en Sistemas Inteligentes del curso 2015/2016. El proyecto tiene un ´ámbito documental para el estudio y evaluación de varios marcos de desarrollo para sistemas distribuidos basados en el paradigma de agentes. El objetivo principal del proyecto consiste en realizar un estudio de las principales características y propiedades de las nuevas APIs (Application Programming Interface) en Java disponibles para el desarrollo de sistemas inteligentes distribuidos en el contexto de sistemas gestores de tráfico y transporte. Para conseguir este objetivo se plantea el análisis de dos de estas APIs: WADE y AMUSE; ambas basadas en la plataforma reconocida de forma internacional JADE. Además del estudio de ambas tecnologías durante la prolongada fase de documentación, se han desarrollado una serie de programas de prueba tratando de explotar los puntos fuertes de cada uno y explorar de forma práctica sus diferentes características. Como punto final se ha desarrollado un proyecto de gestión de tráfico urbano para la interacción eficiente entre vehículos en intersecciones. La sección de esta memoria destinada a resultados experimentales se ha centrado en este último proyecto y en las simulaciones que se han llevado a cabo

Hunting for new physics signals in the LHC era

Currently, the Standard Model of particle physics is able to satisfactorily explain three out to the four fundamental interactions of matter: strong, weak and electromagnetic interactions. However, there are many aspects that this fantastic theory is not able to explain and there must certainly be something beyond it. This thesis aims to find out if there is any indication in the current data of the accelerators that suggests the existence of new physics. We intend, therefore, to determine to which extent some of the new physics models that have been proposed in the literature may be plausible given current data. In this way, we will be able to find constraints on the parameter space of models that extend the scalar sector of the Standard Model with coloured scalars. In addition, we will also be able to constrain the new physics electroweak couplings of the top quark. This thesis is organised in 8 chapters. First of all, in Chapter 1, we present the Standard Model of particle physics, following a (brief) historical perspective. We will see the different facts that led to the final development of this extremely successful theory. Once the Standard Model is well understood, we start to describe in Chapter 2 a possible extension of its scalar sector. The extension that will be presented contains an additional doublet of SU(2)L that is also an octet of SU(3)C. First, we will briefly motivate this model and later explain its most general potential, as well as the different interactions of the new scalars with the Standard Model particles. In Chapter 3 we describe the model-independent framework of Effective Field Theory. We describe the fundamental theorems that lead to this framework and also its extreme relevance for both bottom-up and top-down approaches. In order to do this, we present two examples that will be useful for our research work that will be later described: the Standard Model Effective Field Theory and the Low Energy Effective Field Theory. We finish this chapter with some technical details, which are crucial to predict observables in this framework. Then, in Chapter 4, we present an extremely useful code, HEPfit, that will be used to perform fits in Chapters 6 and 8. In this chapter we will also include a brief discussion about the statistical frameworks that we use in particle physics. Furthermore, we will talk about the Markov Chain Monte Carlo method, which is implemented in this code. The following three Chapters 5, 6 and 7 contain some phenomenological studies of the model presented in Chapter 2. First, in Chapter 5 we find constraints on the masses of the new scalar particles, using data from direct searches at the Large Hadron Collider. After that we perform a global fit of this model, in the CP-conserving limit. As we have already mentioned, in order to do this fit we use the HEPfit code, described in Chapter 4. In this global fit we include all the relevant available observables for this model, including the direct searches of Chapter 5, as well as imposing some theoretical considerations. Finally, in Chapter 7 we present novel contributions of the colour-octet scalars to the electric dipole moment of the neutron. Apart from providing the analytical results, we briefly study the current limits that this observable can generate on its parameter space. The last chapter of the thesis, Chapter 8, contains a detailed study of the top-quark electroweak couplings. In this chapter we employ the model-independent framework that we describe in Chapter 3 to study the effects of possible new-physics particles in the top-quark electroweak couplings. In particular, we present a global fit, performed with HEPfit, within the framework of the Standard Model Effective Field Theory. In order to perform this fit we use the most recent data coming from the Run 2 of the Large Hadron Collider, as well as including some data from LEP and the Tevatron that is still relevant. We finish this chapter studying how these limits would be improved with the data of the High-Luminosity Large Hadron Collider and an electron-positron collider working at different energy ranges

Giant Enhancement in the Supercapacitance of NiFe-Graphene Nanocomposites Induced by a Magnetic Field

The rapid rise in energy demand in the past years has prompted a search for low-cost alternatives for energy storage, supercapacitors being one of the most important devices. It is shown that a dramatic enhancement (≈1100%, from 155 to 1850 F g−1) of the specific capacitance of a hybrid stimuli-responsive FeNi3-graphene electrode material can be achieved when the charge/ discharge cycling is performed in the presence of an applied magnetic field of 4000 G. This result is related to an unprecedented magnetic-field-induced metal segregation of the FeNi3 nanoparticles during the cycling, which results in the appearance of small Ni clusters (<5 nm) and, consequently, in an increase in pseudocapacitive sites. The results open the door to a systematic improvement of the capacitance values of hybrid supercapacitors, while moving the research in this area towards the development of magnetically addressable energy-storage devices

Fe(II) spin crossover complexes of a derivative of 2,6-bis(pyrazol-1-yl)pyridine (1-bpp) functionalized with a carboxylic acid in the 3-pyridyl position

The preparation of a new bis(pyrazol-1-yl)pyridine (1-bpp) derivative functionalized with a carboxylic acid in the 3-pyridyl position, bpp3-COOH ligand is reported together with the structure and spin-crossover (SCO) properties of [FeII(bpp3-COOH)2](ClO4)2·0.5EtOH·0.5H2O (1). Magnetic properties of 1 indicate that LS is favored. Desolvation leads to a gradual and incomplete SCO. Solvated and desolvated compounds show LIESST effect

Influence of Fe-clustering on the water oxidation performance of two-dimensional layered double hydroxides

Among the two-dimensional (2D) materials family, layered double hydroxides (LDHs) represent a key member due to their unparalleled chemical versatility. In particular, Fe-based LDHs are distinguished candidates due to their high efficiency as oxygen evolution reaction (OER) electrocatalysts. Herein, we have selected MgFe-based LDH phases as model systems in order to decipher whether Fe-clustering exerts an effect on the OER performance. For that, we have optimized hydrothermal synthesis by using triethanolamine (TEA) as the chelating agent. The magnetic characterisation allows us to identify the Fe-clustering degree by following both magnetic susceptibility as well as magnetization values at 2 K. Thanks to this, we demonstrated that TEA induces an increment in Fe-clustering. Electrochemical OER measurements show that both samples behave identically by using glassy carbon electrodes. Interestingly, when the samples are tested in the most commonly employed electrode, nickel foam, striking differences arise. The sample exhibiting a lower Fe-clustering behaves as a better electrocatalyst with a reduction of the overpotential values of more than 50 mV to reach 100 mA cm−2, as a consequence of a favoured surface transformation of MgFe-LDHs phases into more reactive oxyhydroxide NiFe-based phases during the electrochemical tests. Hence, this work alerts about the importance of the electrocatalyst-electrode collector interactions which can induce misinterpretations in the OER performance