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Neutrino Theory in the Precision Era
Asmaa Abada, Gabriela Barenboim, Toni Bertólez-Martínez +76
This document summarises discussions on future directions in theoretical neutrino physics, which are the outcome of a neutrino theory workshop held at CERN in February 2025. The st…
Vector-like Singlet Quarks: a Roadmap
João M. Alves, G. C. Branco, A. L. Cherchiglia +5
We review the theory and phenomenology of isosinglet vector-like quarks (VLQs). In recent years, interest in VLQs has been increasing, due to their contributions to new physics eff…
Complex -symmetric 3HDM
A. Kunčinas, O. M. Ogreid, P. Osland +1
CP violation plays a very important role in nature with implications both for Particle Physics and for Cosmology. Accounting for the observed matter anti-matter asymmetry of the Un…
Light scalars in the Weinberg 3HDM potential with spontaneous CP violation
R. Plantey, O. M. Ogreid, P. Osland +2
The -symmetric 3HDM potential, sometimes called Weinberg's 3HDM potential, can accommodate both explicit and spontaneous CP violation as well as natu…
Vector-like Quarks
Gustavo Castelo Branco, M. N. Rebelo
In this talk we emphasise the importance of vector-like quarks (VLQs) and their potential to solve some of the open questions of the Standard Model. These are, in some sense minima…
Weinberg's 3HDM potential with spontaneous CP violation
R. Plantey, O. M. Ogreid, P. Osland +2
We study the potential of Weinberg's -symmetric three-Higgs-doublet model (3HDM). The potential is designed to accommodate CP violation in the scala…
Dark matter in a CP-violating three-Higgs-doublet model with symmetry
A. Kunčinas, O. M. Ogreid, P. Osland +1
In spite of the success of the Standard Model of Particle Physics, there are some theoretical predictions which are not yet fully established experimentally as well as some experim…
3HDM with symmetry and its phenomenological consequences
J. Kalinowski, W. Kotlarski, M. N. Rebelo +1
We perform a comprehensive analysis of a version of the 3-Higgs doublet model whose scalar potential is invariant under a global discrete symmetry and where the three scala…
Decays of the Heavy Top and New Insights on in a one-VLQ Minimal Solution to the CKM Unitarity Problem
Francisco J. Botella, G. C. Branco, M. N. Rebelo +2
We propose a minimal extension of the Standard Model where an up-type vector-like quark, denoted , is introduced and provides a simple solution to the CKM unitarity problem. We…
Dark matter in three-Higgs-doublet models with symmetry
W. Khater, A. Kunčinas, O. M. Ogreid +2
Models with two or more scalar doublets with discrete or global symmetries can have vacua with vanishing vacuum expectation values in the bases where symmetries are imposed. If a s…
Addressing the CKM Unitarity Problem with a Vector-like Up Quark
G. C. Branco, J. T. Penedo, Pedro M. F. Pereira +2
We point out that hints of deviations from unitarity in the first row of the CKM matrix may be explained by the presence of a single vector-like top. We study how the stringent exp…
Type-I Seesaw with eV-Scale Neutrinos
G. C. Branco, J. T. Penedo, Pedro M. F. Pereira +2
We consider seesaw type-I models including at least one (mostly-)sterile neutrino with mass at the eV scale. Three distinct situations are found, where the presence of light extra…
-inspired three-Higgs-doublet models: A class with a complex vacuum
A. Kuncinas, O. M. Ogreid, P. Osland +1
In this paper we analyse in detail an -symmetric three-Higgs-doublet model with a specific vacuum configuration. This analysis allows us to illustrate important features of mo…
Implications of symmetries in the scalar sector
Howard E. Haber, O. M. Ogreid, P. Osland +1
Symmetries play a very important rôle in Particle Physics. In extended scalar sectors, the existence of symmetries may permit the models to comply with the experimental constraints…
Symmetries and Mass Degeneracies in the Scalar Sector
Howard E. Haber, O. M. Ogreid, P. Osland +1
We explore some aspects of models with two and three SU(2) scalar doublets that lead to mass degeneracies among some of the physical scalars. In Higgs sectors with two scalar doubl…
Solving a Fine-Tuning Problem of the Standard Model through the Introduction of Vector-Like Quarks
F. J. Botella, G. C. Branco, M. Nebot +2
We emphasise that even in the extreme chiral limit where only the top and bottom quarks acquire mass, quark mixing is physically meaningful. This implies that the natural value of…
Neutrino Physics and Leptonic Weak Basis Invariants
M. N. Rebelo
In this talk we present a powerful tool applied to the study of Leptonic Physics. This tool is based on the construction of Weak Basis invariant relations associated to different p…
CP violation in extended Higgs sectors
O. M. Ogreid, P. Osland, M. N. Rebelo
We discuss how one can identify CP violation (and conservation) in multi-Higgs-doublet potentials. After a brief review of CP violation in the 2HDM, we refer to the fact that for N…
Can One have Significant Deviations from Leptonic Unitarity in the Framework of Type I Seesaw Mechanism?
Nuno Rosa Agostinho, G. C. Branco, Pedro M. F. Pereira +2
We address the question of deviations from unitarity of the leptonic mixing matrix showing that, contrary to conventional wisdom, one may have significant deviations fr…
Leptonic Invariants, Neutrino Mass-Ordering and the Octant of
G. C. Branco, M. N. Rebelo, J. I. Silva-Marcos
We point out that leptonic weak-basis invariants are an important tool for the study of the properties of lepton flavour models. In particular, we show that appropriately chosen in…
The discrete charm of flavour and CP violation
G. C. Branco, M. N. Rebelo
We point out that in the Standard Model (SM) there is no explanation why is of order . A framework is described for explaining this small mixing,…
Spontaneous symmetry breaking in three-Higgs-doublet -symmetric models
D. Emmanuel-Costa, O. M. Ogreid, P. Osland +1
The talk summarises work done by the authors consisting of a detailed study of the possible vacua in models with three Higgs doublets with symmetry and without explicit CP vi…
Vector-like Quarks at the Origin of Light Quark Masses and Mixing
Francisco J. Botella, G. C. Branco, Miguel Nebot +2
We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a single flavour symmetry G, together with three quarks,…
What if the Masses of the First Two Quark Families are not Generated by the Standard Higgs?
F. J. Botella, G. C. Branco, M. N. Rebelo +1
We point out that, in the context of the SM, is expected to be large, of order one. The fact that mo…