Publications (67)
Transmission Line Pulse (TLP) as integrative method for the investigation of ultra-fast trapping mechanisms on high-k MIM
Luca Merlo, Isabella Rossetto, Lorenzo Cerati +8
This paper discusses the transmission line pulse (TLP) analysis, generally used for electrostatic discharge (ESD) device characterization, as high potential usable tool also for no…
Unified unconditional regression for multivariate quantiles, M-quantiles and expectiles
Luca Merlo, Lea Petrella, Nicola Salvati +1
In this paper, we develop a unified regression approach to model unconditional quantiles, M-quantiles and expectiles of multivariate dependent variables exploiting the multidimensi…
Tri-Bimaximal Neutrino Mixing and Discrete Flavour Symmetries
Guido Altarelli, Ferruccio Feruglio, Luca Merlo
We review the application of non-Abelian discrete groups to Tri-Bimaximal (TB) neutrino mixing, which is supported by experiment as a possible good first approximation to the data.…
Cosmic Imprints of XENON1T Axions
Fernando Arias-Aragon, Francesco D'Eramo, Ricardo Z. Ferreira +2
The recent electron recoil excess observed by XENON1T has a possible interpretation in terms of solar axions coupled to electrons. If such axions are still relativistic at recombin…
Estimating causal quantile exposure response functions via matching
Luca Merlo, Francesca Dominici, Lea Petrella +2
We develop new matching estimators for estimating causal quantile exposure-response functions and quantile exposure effects with continuous treatments. We provide identification re…
Repressing Anarchy in Neutrino Mass Textures
Guido Altarelli, Ferruccio Feruglio, Isabella Masina +1
The recent results that is relatively large, of the order of the previous upper bound, and the indications of a sizable deviation of from the maximal value are…
Neutrino Mixings and the S4 Discrete Flavour Symmetry
Federica Bazzocchi, Luca Merlo
Discrete non-Abelian Symmetries have been extensively used to reproduce the lepton mixings. In particular, the S4 group turned out to be suitable to describe predictive mixing patt…
Flavour violation in a supersymmetric T' model
Luca Merlo, Stefano Rigolin, Bryan ZaldÃvar
We describe the phenomenology of the flavour changing neutral current sector of a supersymmetric model, invariant under the T' discrete flavour group. This model has been proposed…
On Continuous Flavour Symmetries for Neutrinos
Luca Merlo
Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the m…
ALPaca: The ALP Automatic Computing Algorithm
Jorge Alda, Marta Fuentes Zamoro, Luca Merlo +2
The ALP Automatic Computing Algorithm, ALPaca, is an open source Python library devoted to studying the phenomenology of Axion-Like Particles (ALPs) with masses in the ranges $m_a…
Phenomenology of a Gauged SU(3)^3 Flavour Model
Andrzej J. Buras, Maria Valentina Carlucci, Luca Merlo +1
We present an extensive analysis of Delta F=2 observables and of B -> X_s gamma in the framework of a specific Maximally Gauged Flavour (MGF) model of Grinstein et al. including al…
Theory of the Neutrino Mass
Ferruccio Feruglio, Claudia Hagedorn, Yin Lin +1
Theoretical aspects of neutrino physics are reviewed, with emphasis on possible explanations of the smallness of neutrino masses and of the peculiar mixing pattern observed in the…
The Data Driven Flavour Model
Luca Merlo
A bottom-up approach has been adopted to identify a flavour model that agrees with present experimental measurements. The charged fermion mass hierarchies suggest that only the top…
Phenomenology of Discrete Flavour Symmetries
Luca Merlo
The flavour puzzle is an open problem both in the Standard Model and in its possible supersymmetric or grand unified extensions. In this thesis, we discuss possible explanations of…
Discrete Flavour Groups, θ_13 and Lepton Flavour Violation
Guido Altarelli, Ferruccio Feruglio, Luca Merlo +1
Discrete flavour groups have been studied in connection with special patterns of neutrino mixing suggested by the data, such as Tri-Bimaximal mixing (groups A4, S4...) or Bi-Maxima…
The Impact of Flavour Changing Neutral Gauge Bosons on B->X_s gamma
Andrzej J. Buras, Luca Merlo, Emmanuel Stamou
The branching ratio of the rare decay B->X_s gamma provides potentially strong constraints on models beyond the Standard Model. Considering a general scenario with new heavy neutra…
Theoretical Models for Neutrino Masses
Luca Merlo
The recent measurements of the neutrino reactor angle require a re-examination of flavour models based on discrete groups. Indeed, when these models deal with the Tri-Bimaximal, th…
Visible GeV ALP from TeV Vector-like Leptons
Arturo de Giorgi, Marta Fuentes Zamoro, Luca Merlo
We present a model where a GeV axion-like-particle (ALP) is predicted in a large portion of the parameter space due to the presence of explicit Peccei-Quinn symmetry-breaking terms…
Hilbert series for covariants and their applications to Minimal Flavor Violation
BenjamÃn Grinstein, Xiaochuan Lu, Luca Merlo +1
We elaborate how to apply the Hilbert series method to enumerating group covariants, which transform under any given representation, including but going beyond group invariants. Ma…
Quantile Mixed Hidden Markov Models for multivariate longitudinal data
Luca Merlo, Lea Petrella, Nikos Tzavidis
The identification of factors associated with mental and behavioral disorders in early childhood is critical both for psychopathology research and the support of primary health car…
The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model
Reinier de Adelhart Toorop, Federica Bazzocchi, Luca Merlo
Both Grand Unified symmetries and discrete flavour symmetries are appealing ways to describe apparent structures in the gauge and flavour sectors of the Standard Model. Both symmet…
Inter-order relations between moments of a Student distribution, with an application to -quantiles
Valeria Bignozzi, Luca Merlo, Lea Petrella
This paper introduces inter-order formulas for partial and complete moments of a Student distribution with degrees of freedom. We show how the partial moment of order $n -…
Running Effects on Lepton Mixing Angles in Flavour Models with Type I Seesaw
Yin Lin, Luca Merlo, Alessio Paris
We study renormalization group running effects on neutrino mixing patterns when a (type I) seesaw model is implemented by suitable flavour symmetries. We are particularly intereste…
Forecasting VaR and ES using a joint quantile regression and implications in portfolio allocation
Luca Merlo, Lea Petrella, Valentina Raponi
In this paper we propose a multivariate quantile regression framework to forecast Value at Risk (VaR) and Expected Shortfall (ES) of multiple financial assets simultaneously, exten…
A Bayesian comparison of U(1) lepton flavour models
Johannes Bergstrom, Davide Meloni, Luca Merlo
Whether the anarchical ansatz or more symmetric structures best describe the neutrino parameters is a long standing question that underwent a revival of interest after the discover…
Expectile hidden Markov regression models for analyzing cryptocurrency returns
Beatrice Foroni, Luca Merlo, Lea Petrella
In this paper we develop a linear expectile hidden Markov model for the analysis of cryptocurrency time series in a risk management framework. The methodology proposed allows to fo…
Ultraviolet Completion of Flavour Models
Ivo de Medeiros Varzielas, Luca Merlo
Effective Flavour Models do not address questions related to the nature of the fundamental renormalisable theory at high energies. We study the ultraviolet completion of Flavour Mo…
ALPs and HNLs at LHC and Muon Colliders: Uncovering New Couplings and Signals
Marta Burgos Marcos, Arturo de Giorgi, Luca Merlo +1
Axion-like particles (ALPs) and heavy neutral leptons (HNLs) are two well-motivated classes of particles beyond the Standard Model. It is intriguing to explore the new detection op…
LFV and Dipole Moments in Models with A4 Flavour Symmetry
Luca Merlo
It is presented an analysis on lepton flavour violating transitions, leptonic magnetic dipole moments and electric dipole moments in a class of models characterized by the flavour…
Comprehensive ALP Searches in Meson Decays
Jorge Alda, Marta Fuentes Zamoro, Luca Merlo +2
We present a comprehensive study of axion-like particles (ALPs) in meson decays, combining effective field theory and ultraviolet models within the open-source tool ALPaca. The ana…
Weak complementarity from discrete symmetries
Luca Merlo
The neutrino oscillation data find a good approximation in the so-called tri-bimaximal pattern. Recently a paper appeared showing that also the bimaximal pattern, which is already…
A T' Flavour Model for Fermions and its Phenomenology
Luca Merlo
We present a supersymmetric flavour model based on the T' discrete group, which explains fermion masses and mixings. The flavour symmetry, acting in the supersymmetric sector, prov…
Lepton Flavour Violation in Models with A4 Flavour Symmetry
Ferruccio Feruglio, Claudia Hagedorn, Yin Lin +1
We analyze lepton flavour violating transitions, leptonic magnetic dipole moments (MDMs) and electric dipole moments (EDMs) in a class of models characterized by the flavour symmet…
Vacuum Alignment in SUSY A4 Models
Ferruccio Feruglio, Claudia Hagedorn, Luca Merlo
In this note we discuss the vacuum alignment in supersymmetric models with spontaneously broken flavour symmetries in the presence of soft supersymmetry (SUSY) breaking terms. We s…
Fermion Masses and Mixings in a S4 Based Model
Federica Bazzocchi, Luca Merlo, Stefano Morisi
It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this featur…
V-Associated Production & Vector Boson Fusion as an LHC Signature of CP Violation
Rodrigo Capucha, Ãlvaro Lozano-Onrubia, Luca Merlo +2
We investigate the role of vector boson fusion (VBF) and associated production with an electroweak boson (V-AP) of beyond-the-Standard-Model Higgses at the LHC in probing CP violat…
The Low-Scale Seesaw Solution to the and Anomalies
Arturo de Giorgi, Luca Merlo, Stefan Pokorski
The recent CDF-II measurement of the -boson mass shows a strong tension with the corresponding Standard Model prediction. Once active neutrino masses are explained in the contex…
Neutrino Masses and Hubble Tension via a Majoron in MFV
Fernando Arias-Aragon, Enrique Fernandez-Martinez, Manuel Gonzalez-Lopez +1
The recent tension between local and early measurements of the Hubble constant can be explained in a particle physics context. A mechanism is presented where this tension is allevi…
LFV in Models with A4 Flavour Symmetry
Luca Merlo
The approximated tri-bimaximal mixing observed in the neutrino oscillations is a particular feature of a class of models characterized by the spontaneously broken horizontal flavou…
Minimal flavour violation extensions of the seesaw
Rodrigo Alonso, Gino Isidori, Luca Merlo +2
We analyze the most natural formulations of the minimal lepton flavour violation hypothesis compatible with a type-I seesaw structure with three heavy singlet neutrinos N, and sati…
Baryon Non-Invariant Couplings in Higgs Effective Field Theory
Luca Merlo, Sara Saa, Mario Sacristan-Barbero
The basis of leading operators which are not invariant under baryon number is constructed within the Higgs Effective Field Theory. This list contains 12 dimension six operators, wh…
Dark matter within the minimal flavour violation ansatz
Laura Lopez-Honorez, Luca Merlo
Minimal Flavour Violation hypothesis can provide an attractive framework for Dark Matter (DM). We consider scalar DM candidates carrying flavour quantum numbers and whose represent…
Hidden Markov graphical models with state-dependent generalized hyperbolic distributions
Beatrice Foroni, Luca Merlo, Lea Petrella
In this paper we develop a novel hidden Markov graphical model to investigate time-varying interconnectedness between different financial markets. To identify conditional correlati…
Probing HNL-ALP couplings at colliders
Arturo de Giorgi, Luca Merlo, Jean-Loup Tastet
Axion-like particles (ALPs) and heavy neutral leptons (HNLs) are both well-motivated extensions of the Standard Model. As ALPs couple to on-shell fermions proportionally to their m…
Dynamical Minimal Flavour Violating Inverse Seesaw
Fernando Arias-Aragón, Enrique Fernández-MartÃnez, Manuel González-López +1
The Inverse Seesaw mechanism is dynamically realised within the Minimal Lepton Flavour Violation context. Lepton number, whose breaking is spontaneously realised, is generalised to…
The COSMIC WISPers White Paper: The physics case for Weakly Interacting Slim Particles
Ariel Arza, Deniz Aybas, Shyam Balaji +124
Axions and other very weakly interacting slim particles (WISPs), with masses below 1 GeV, arise naturally in many extensions of the Standard Model of particle physics. In particula…
WISPedia -- the WISPs Encyclopedia
Conrado Albertus, Francesca Chadha-Day, Arturo de Giorgi +8
The Weakly-Interacting Slim Particle encyclopedia (WISPedia) is a comprehensive reference work dedicated to the systematic compilation of theoretical models, Effective Field Theori…
GeV ALP from TeV Vector-like leptons
Arturo de Giorgi, Marta Fuentes Zamoro, Luca Merlo
We present a model where a GeV axion-like-particle (ALP) is predicted in a large portion of the parameter space due to the presence of explicit Peccei-Quinn symmetry-breaking terms…
Constraining Flavour Symmetries At The EW Scale I: The A4 Higgs Potential
Reinier de Adelhart Toorop, Federica Bazzocchi, Luca Merlo +1
We consider an extension of the Standard Model in which the symmetry is enlarged by a global flavour factor A4 and the scalar sector accounts for three copies of the Standard Model…
Tri-bimaximal and bimaximal neutrino mixing from discrete symmetries
Luca Merlo
The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently it has been shown that also the bimaximal pattern could be a very good starting point in ord…
Constraining Flavour Symmetries At The EW Scale II: The Fermion Processes
Reinier de Adelhart Toorop, Federica Bazzocchi, Luca Merlo +1
We study the set of models in which the Standard Model symmetry is extended with the flavour group A4 and there are three copies of the Standard Model Higgs that transform as a tri…
Quantile mixed graphical models with an application to mass public shootings in the United States
Luca Merlo, Marco Geraci, Lea Petrella
Over the last fifty years, the United States have experienced hundreds of mass public shootings that resulted in thousands of victims. Characterized by their frequent occurrence an…
The Minimal Massive Majoron Seesaw Model
Arturo de Giorgi, Luca Merlo, Xavier Ponce DÃaz +1
A convincing explanation of the smallness of neutrino masses is represented by the Type-I Seesaw mechanism, where the two measured neutrino mass differences can be generated by int…
Bimaximal neutrino mixing and weak complementarity with S4 discrete symmetry
Luca Merlo
The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently a paper appeared showing that also the bimaximal pattern could be a very good starting point…
Tri-bimaximal Neutrino Mixing and Quark Masses from a Discrete Flavour Symmetry
Ferruccio Feruglio, Claudia Hagedorn, Yin Lin +1
We build a supersymmetric model of quark and lepton masses based on the discrete flavour symmetry group T', the double covering of A_4. In the lepton sector our model is practicall…
Early Universe hypercharge breaking and neutrino mass generation
Sergio López-Zurdo, Ãlvaro Lozano-Onrubia, Luca Merlo +1
We show that the conditions allowing for a spontaneous breaking of the hypercharge gauge symmetry of the Standard Model (SM) in the early Universe are generically present…
Sigma Decomposition
Rodrigo Alonso, Ilaria Brivio, Belen Gavela +2
In composite Higgs models the Higgs is a pseudo-Goldstone boson of a high-energy strong dynamics. We have constructed the effective chiral Lagrangian for a generic symmetric coset,…
Production of Thermal Axions across the ElectroWeak Phase Transition
Fernando Arias-Aragon, Francesco D'Eramo, Ricardo Z. Ferreira +2
Light axions can potentially leave a cosmic background, just like neutrinos. We complete the study of thermal axion production across the electroweak scale by providing a smooth an…
Crossing into the Region for Leptophilic ALPs
Marta F. Zamoro, Ãlvaro Lozano-Onrubia, Luca Merlo +1
Axion-like particles (ALPs) are typically identified as pseudoscalars whose couplings are shift-symmetry invariant with the exception of their couplings to gauge bosons and their m…
A two-part finite mixture quantile regression model for semi-continuous longitudinal data
Antonello Maruotti, Luca Merlo, Lea Petrella
This paper develops a two-part finite mixture quantile regression model for semi-continuous longitudinal data. The proposed methodology allows heterogeneity sources that influence…
Flavour and Higgs physics in -symmetric 2HD models near the decoupling limit
Arturo de Giorgi, Fotis Koutroulis, Luca Merlo +1
With no evidence of any exotic particle detected so far beyond the Standard Model, the new physics may lie above the presently accessible energies at colliders and, at low-energies…
Testable Axion-Like Particles In The Minimal Linear Ï Model
Javier Alonso-Gonzalez, Luca Merlo, Federico Pobbe +2
Axion and axion-like particle models are typically affected by a strong fine-tuning problem in conceiving the electroweak and the Peccei-Quinn breaking scales. Within the context o…
Neutrino Masses and Mixings from Continuous Symmetries
Luca Merlo
Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the m…
Lepton Flavour Violation in a Supersymmetric Model with A4 Flavour Symmetry
Ferruccio Feruglio, Claudia Hagedorn, Yin Lin +1
We compute the branching ratios for mu-> e gamma, tau-> mu gamma and tau -> e gamma in a supersymmetric model invariant under the flavour symmetry group A4 X Z3 X U(1)_{FN}, in whi…
Proceedings of the first workshop on Flavor Symmetries and consequences in Accelerators and Cosmology (FLASY2011)
M. Hirsch, D. Meloni, S. Morisi +43
The main goals of the first "Workshop on FLAvor SYmmetries and consequences in accelerators and cosmology" (FLASY) was to summarize the theoretical status of flavor symmetries, bri…
Quantile and expectile copula-based hidden Markov regression models for the analysis of the cryptocurrency market
Beatrice Foroni, Luca Merlo, Lea Petrella
The role of cryptocurrencies within the financial systems has been expanding rapidly in recent years among investors and institutions. It is therefore crucial to investigate the ph…
Bimaximal Neutrino Mixing with Discrete Flavour Symmetries
Luca Merlo
In view of the fact that the data on neutrino mixing are still compatible with a situation where Bimaximal mixing is valid in first approximation and it is then corrected by terms…