arXiv subjects

Andrea Sainaghi

Publications and source records attributed to Andrea Sainaghi.

6 recordsLinked to original sources

arXiv2026

EFT Pathways to $|ΔB| =2$: Chiral Constructions and Phenomenology

We develop a systematic effective field theory framework for studying $|ΔB|=2$ interactions across energy scales. Using chiral symmetry, we construct the complete and non-redundant set of operators governing these interactions at low energies and establish their connection to the corresponding operators in the Standard Model effective field theory, as well as to their realizations in baryon chiral perturbation theory. The framework is then applied to the phenomenology of baryon-antibaryon oscillations and dinucleon decay. While oscillations probe only a limited subset of operator structures, dinucleon decay is sensitive to a significantly broader class, including transitions that are otherwise inaccessible. In addition, we identify previously unexplored dinucleon decay channels, which can probe these unconstrained regions of parameter space. More generally, this formalism makes explicit the complementarity of different probes and provides a consistent way to trace baryon-number-violating effects from their ultraviolet origin to low-energy hadronic observables, thereby providing a basis for systematic studies of ultraviolet models generating such interactions.

hep-ph↗

arXiv2026

Anatomy and Phenomenology of Minimal Flavor Deconstruction in the Lepton Sector

We investigate the low-energy phenomenology of a minimal flavor-deconstructed framework in the lepton sector within an effective field theory approach, focusing on the interplay between flavor and CP violation. Starting from the ultraviolet completion of the model, we derive the effective Yukawa structure through a systematic spurion expansion beyond leading order and identify the dominant sources of flavor and CP violation. We show that, while leading-order effects to dipole operators are approximately aligned with the Yukawa matrices, next-to-leading order contributions generically induce physical CP-violating phases and flavor misalignment, leading to potentially observable low-energy signals. After constructing the corresponding low-energy effective theory, we analyze the phenomenological implications for charged lepton flavor violating observables, lepton flavor universality tests, and electric dipole moments (EDMs). We find that future searches for $μ-e$ conversion and the electron EDM can probe scales in the multi-10~TeV range under natural assumptions on the flavor structure and CP phases. Our results highlight the complementarity between flavor-violating and CP-violating observables and demonstrate that precision measurements in the lepton sector provide a powerful probe of flavor-deconstructed scenarios beyond the direct reach of collider experiments.

hep-ph↗

arXiv2026

Implications of Flavor Symmetries for Baryon Number Violation

In the Standard Model, baryon number is an accidental symmetry, whose violation would constitute unambiguous evidence of new physics, with proton decay providing its most prominent experimental signature. At the same time, the peculiar structure of flavor can serve as a guiding principle for exploring possible new-physics effects. In this work, we present a systematic classification of dimension-six baryon-number-violating (BNV) SMEFT operators across several flavor-symmetry assumptions and analyze the resulting phenomenology. Interestingly, in certain flavor scenarios the non-trivial interplay with tiny neutrino masses leads to proton-decay constraints compatible with BNV scales in the multi-TeV range. Finally, we complement the EFT analysis by identifying one-particle UV completions of the BNV operators, revealing scenarios in which the leading-order EFT description may not fully account for their underlying dynamics.

hep-ph↗

arXiv2026

Unitarity bounds and sum rules in the SMEFT

We present a comprehensive reassessment of perturbative unitarity bounds in the dimension-six Standard Model Effective Field Theory, exploiting a new formalism based on spinor-helicity techniques to derive partial-wave unitarity bounds for generic $N \to M$ scattering amplitudes. We find that, in several cases, these theoretical constraints are already competitive with, or even stronger than, the corresponding experimental bounds for energy scales above a few TeV. This is especially the case for four-fermion operators under realistic flavor assumptions, where unitarity bounds can be further strengthened by exploiting sum rules.

hep-ph↗

arXiv2025

Anarchic neutrinos from flavor deconstruction: phenomenology of the lepton sector

We investigate the neutrino sector in the framework of flavor deconstruction with an inverse-seesaw realization. This setup naturally links the hierarchical charged-fermion masses to the anarchic pattern of light-neutrino mixing. We determine the viable parameter space consistent with oscillation data and study the phenomenology of heavy neutral leptons (HNL) and lepton-flavor-violating (LFV) processes. Current bounds from direct HNL searches and LFV decays constrain the right-handed neutrino scale to a few TeV, while future $μ\to e$ experiments will probe most of the region with $Λ\lesssim 10~\text{TeV}$. Among possible realizations, models deconstructing $\mathrm{SU}(2)_\mathrm{L} \times \mathrm{U}(1)_\mathrm{B-L}$ or $\mathrm{SU}(2)_\mathrm{L} \times \mathrm{U}(1)_\mathrm{R} \times \mathrm{U}(1)_\mathrm{B-L}$ are those allowing the lowest deconstruction scale.

hep-ph↗

arXiv2022

Maximally symmetric nonlinear extension of electrodynamics and charged particles

We consider couplings of electrically and magnetically charged sources to the maximally symmetric non-linear extension of Maxwell's theory called ModMax. The aim is to reveal physical effects which distinguish ModMax from Maxwell's electrodynamics. We find that, in contrast to generic models of non-linear electrodynamics, Lienard-Wiechert fields induced by a moving electric or magnetic particle, or a dyon are exact solutions of the ModMax equations of motion. We then study whether and how ModMax non-linearity affects properties of electromagnetic interactions of charged objects, in particular the Lorentz force, the Coulomb law, the Lienard-Wiechert fields, Dirac's and Schwinger's quantization of electric and magnetic charges, and the Compton Effect. In passing we also present an alternative form of the ModMax Lagrangian in terms of the coupling of Maxwell's theory to axion-dilaton-like auxiliary scalar fields which may be relevant for revealing the effective field theory origin of ModMax.

hep-th↗