Extensions of the scalar sector of the Standard Model

Tese de mestrado, Física (Física Nuclear e Partículas) Universidade de Lisboa, Faculdade de Ciências, 2020The matter-antimatter asymmetry observed in the Universe cannot be explained by the amount of violation of Charge Conjugation and Parity (CP) in the Standard Model (SM). This shortcoming of the SM is one of the main motivations that led to the proposal of several extensions of the SM with new sources of CP-violation, a necessary requirement to explain the baryon asymmetry, according to the Sakharov conditions for baryogenesis. In this thesis, we will look at some of the main features of a particular type of models where the SM Higgs potential is changed by the addition of a second scalar doublet to the SM field content. These models are known as Two-Higgs-Doublet Models (2HDMs). They provide a very rich phenomenology at the Large Hadron Collider (LHC) and future colliders because of the introduction of new scalar states, and may answer many unsolved problems that are not addressed in the SM, such as the insufficiency of CP-violation and the existence of Dark Matter (DM). The CP-nature of the discovered Higgs is still an open issue. While it has been established by the ATLAS (A Toroidal LHC Apparatus) and CMS (Compact Muon Solenoid) collaborations that the discovered scalar cannot be a pure pseudoscalar, a mixed state with a large CP-odd component is still possible. This would be an indication of CP-violation in the scalar sector. The search for new sources of CP-violation and Beyond the Standard Model (BSM) physics is one of the main goals of the LHC. This can be achieved by a precise measurement of the Yukawa couplings since the CP-nature of the Higgs can be directly probed in its production alongside fermions. In this dissertation, we explore the sensitivity of CP-discrimination in the Higgs (h) couplings to bottom (b) and top quarks (t), for b ¯bh, bh and in dilepton final states of tth¯ events (with h → b ¯b) produced at the LHC and generated with MadGraph5 aMC@NLO. These Higgs bosons are generic, i.e., they may not correspond to the discovered one with a mass of 125 GeV, and are either pure CP-even or pure CP-odd. Several observables introduced in previous works are evaluated for a varying scalar boson mass, mh, in order to probe the CP-sensitivity in the different processes. We show that for b ¯bh and bh final states, CP-discrimination is not possible for the observables considered, even for very light Higgs masses of 10 GeV. For tth¯ , we found that distinguishing different CP states becomes increasingly difficult for larger masses, and seemingly impossible for masses above 450 GeV, at parton level. For the tops, we additionally apply an algorithm to reconstruct, for the first time, tth¯ events with a Higgs mass different from 125 GeV. Confidence Levels (CLs) for exclusion are computed for this process, as a function of the LHC luminosity, for different scenarios. We found that exclusion scenarios at the LHC require more luminosity for a fixed CL as we increase the scalar boson mass. CP-odd exclusion also requires more luminosity, relative to CP-even exclusion, for mh < 160 GeV. With the current LHC luminosity of 150 fb−1 , exclusion of a pure CP-even Higgs with a mass below 80 GeV, assuming SM-like couplings, is already possible. Also, the information that we may learn in these exclusion scenarios still leaves a large allowed parameter space for the Complex Two-Higgs-Doublet Model (C2HDM)

Digital society and the fight against poverty: New skills in social work

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Student-centered and ICT-enabled learning models in veterinarian programs: what changed with COVID-19?

COVID-19 highlighted higher education’s resistance to implementing the student-centered and ICT (information and communication technology)-enabled learning practices as incentivized by the Bologna Declaration. ICTs were crucial to keep the students in educational programs during the outbreak; however, some students were left out, increasing socioeconomic differences, and many teachers needed the training to provide online lectures effectively. Despite those barriers, the current context could be an opportunity to invest in new teaching and learning practices. The main goal of this research is to analyze how teachers and students from veterinary programs in Portugal adapted to the digital environment, and perceive whether this change imposed by COVID-19 could provide teachers and higher institutions with new solutions to implement effective student-centered and ICT-enabled learning models. Results show that veterinary programs are based on student-centered practices by nature, but that the use of ICTs is still incipient. Teachers, students, and members from the Professional Order claim that the worst change brought by COVID-19 was the cancellation of hands-on sessions, impoverishing the students’ education during the time of mandatory confinement. Actors say that it is important to invest in innovative teaching and learning practices enabled by ICTs in the future.info:eu-repo/semantics/publishedVersio

The welfare state: too precious to fall

The Welfare State is the political institution that further took the idea of solidarity and social justice in the History of Humanity. Unequally developed in the world, it reached high levels of efficiency in Europe in improving the living conditions of the populations and in promoting social rights. It is, however, under pressure from financial constraints and threatened politically and ideologically by neoliberalism and financial capitalism in a globalized world. Therefore, in the last decades, the word “crisis” is, perhaps, the most often used in the debates and research on the Welfare State. And yet, the Welfare State goes on showing trends of expansion, finding paths to evolve, and is, indeed, concerned with a new set of challenges that require the development of new functions. The present paper’s objective is analysing these challenges and functions, in a global perspective, focusing on the ones that are already being tackled and developed, and putting forward the new technological and environmental ones, that are merging and not yet fully known.info:eu-repo/semantics/publishedVersio

International State of the Art Report

The present report is part of the RESCuE project, an acronym that stands for Patterns of Resilience during Socioeconomic Crisis among Households. This project is coordinated by Professor Markus Promberger, from the Institute for Employment Research (IAB), in Germany. It was awarded by the 7th Framework Programme, and funded by the Community Research and Development Information Service (CORDIS). The RESCuE project involves universities and research centres from 9 different European countries – Portugal, Spain, United Kingdom, Ireland, Germany, Poland, Finland, Greece, Turkey – and, in the context of the ongoing economic and financial crisis in Europe, aims to identify and understand the coping and adjusting mechanisms and strategies of different households at risk, thus learn from the resilience of European citizens, in order to find new sustainable ways of reducing poverty risks and inform and support policy making