Conveners
Morning session
- Davide Meloni (Istituto Nazionale di Fisica Nucleare)
Morning session
- Davide Meloni (Istituto Nazionale di Fisica Nucleare)
Morning session
- Ferruccio Feruglio (Istituto Nazionale di Fisica Nucleare)
Morning session
- Arsenii Titov (University of Padua and INFN)
Morning session
- Stefano Morisi (Istituto Nazionale di Fisica Nucleare)
Morning session
- Stefano Morisi (Istituto Nazionale di Fisica Nucleare)
Morning session
- Gustavo Burdman
Morning session
- Claudia Hagedorn (IFIC - UV/CSIC)
Morning session
- Stefan Antusch (University of Basel)
Morning session
- Salvador Centelles Chuliá (IFIC (CSIC - U. Valencia))
We propose a novel quark mass matrix texture-pair with five free parameters, which fits the four quark mass ratios $m_s/m_b$, $m_d/m_b$, $m_c/m_t$, $m_u/m_t$, and the four
CKM quark mixing observables. The matrices each have one texture zero, but the main innovation here is a ``geometric'' ansatz exploiting a pair of small complex expansion parameters, based on the geometry of the Unitarity...
In the canonical seesaw framework flavor mixing and CP violation in weak charged current interactions of light and heavy Majorana neutrinos are correlated with each other and described respectively by the $3\times 3$ matrices $U$ and $R$. We show that the very possibility of $\big|U^{}_{\mu i}\big| = \big|U^{}_{\tau i}\big|$ (for $i = 1, 2, 3$), which is strongly indicated by current neutrino...
In theories of flavor based on modular invariance, correlations between quark and lepton observables are a natural expectation. These arise from their shared dependence on a common modulus field, from joint experimental constraints, and—in the context of Grand Unified Theories (GUTs) — from possible embedding into common gauge multiplets. Despite this, most bottom-up modular flavor models...
In the presence of a finite modular flavour symmetry, fermion mass hierarchies may be
generated by a slight deviation of the modulus from a symmetric point. We point out that
this small parameter governing charged-lepton mass hierarchies may also be responsible
for the breaking of lepton number in a symmetry-protected low-scale seesaw, sourcing
active neutrino masses and the mass splitting...
The original modular flavor symmetry requires supersymmetry to enforce the Yukawa couplings to be holomorphic modular forms. The non-holomorphic modular symmetry is a generation in which supersymmetry is unnecessary in principle. In this talk, we shall present motivation, the formalism and application of non-holomorphic modular symmetry. A predictive model for both quarks and leptons will be...
CP invariance is a very attractive solution to the strong CP problem in QCD. This solution requires the vanishing phase of (det M_d det M_u) of the mass matrices for the down- and up-type quarks. It happens if we have several zeros in the quark mass matrices. We proceed a systematic construction of texture zeros for the quark sector in the T^2/Z3 orbifold compactification. We also extend the...
In this talk, I explore low-scale seesaw scenarios in which a single global U(1) symmetry — and its spontaneous breaking — plays multiple theoretical roles and determines the resulting phenomenology. I will present four example models that share a similar particle content but differ only in their charge assignments, leading to qualitatively distinct physical scenarios, where the Goldstone...
The present acceleration of the Universe can be sourced by the continuous generation of an energy density $\rho_b$ associated with a certain field $\varphi_b$. This idea is implemented by adding a new tensor term to Einstein equation. The creation process requires $\rho_b\neq 0$ as an initial condition, which is enforced by identifying $\varphi_b$ with the axion of a hidden gauge group that...
In recent years, there has been great interest in the community toward New Physics scenarios involving light new degrees of freedom. In this talk, I will discuss the importance of the ultraviolet completion of such scenarios, using the case of a light vector as an example. I will show that the resulting flavour structure is of the Minimal Flavor Violation type, and I will discuss a possible...
Flavor symmetry and other ideas beyond the standard model may be achieved using the dark sector, while keeping only the one SM Higgs doublet.
We present two multi-scalar models, with S3 and Q6 flavour symmetries, respectively. We show how in general the doublet-singlet structure of these types of symmetries accommodates very well the quark sector and CKM matrix. In both models we check whether the co-bimaximal mixing pattern can be found in the neutrino sector. We use S3 as flavour symmetry in a B-L model, and we take complex vev's...
We have been developing the Mathematica package LieART for handling Lie group representation, their products and their decomposition to maximal subgroups. LieART can be a useful tool for model building and other applications. We will give an overview.
Some key topics characterizing 331 models and their viability—both from
a theoretical and phenomenological perspective—are discussed.
In this talk I will discuss the connection between neutrinos and dark sectors. Neutrino masses remain unexplained. Their origin could arise in models at scales below the electroweak one, the so-called dark sectors. I will focus on rich dark sectors that have multiple sectors, in analogy to the Standard Model. I will review how neutrino masses can be generated in such models and how the latter...
Under the assumption that the 2023 pulsar timing array (PTA) results for a stochastic gravitational wave (GW) background at nanohertz frequencies is generated by metastable cosmic strings, we analyze the potential of present and future GW observatories for probing the change of particle degrees of freedom caused, e.g., by a supersymmetric (SUSY) extension of the Standard Model (SM). We find...
I will discuss the formation and properties of domain walls arising from the spontaneous breaking of non-Abelian discrete symmetries, with a focus on the group S4, commonly used in models of lepton flavour. Such symmetry breaking leads to a rich vacuum structure and the emergence of various types of domain walls. While some of these walls are unstable and decay, others can be longer lived and...
We show that baryogenesis can arise from the cosmological evolution of a scalar field that governs CP-violating parameters, such as the Yukawa couplings and the theta terms of the Standard Model. During the Big Bang, this scalar may reach a CP-violating minimum, where its mass can be comparable to the inflationary Hubble scale. Such dynamics can emerge in theories featuring either a...
We systematically investigate the possible phenomenological impact of residual flavour groups in the charged lepton sector. We consider all possible flavour charge assignments for abelian residual symmetries up to Z8. The allowed flavour structures of operators in Standard Model Effective Field Theory (up to dimension six) lead to distinctive and observable patterns of cLFV processes. We...
I will cover some attempts at solving the flavour problem that employ modular flavour symmetries.
