We discuss the status of b→sℓ+ℓ− decays in the post-RK(∗) era. We present a model-independent analysis of the b→sℓ+ℓ− data and investigate the implications of the different sets of observables. Special emphasis will be given to the theoretical uncertainties and challenges.
New calculations for the kinematics of photon decay to fermions in vacuo under an isotropic violation of Lorentz invariance (LV), parameterized by the Standard-Model Extension (SME), are presented in this paper and used to interpret prompt photon production in LHC data. The measurement of inclusive prompt photon production at the LHC Run 2, with photons observed up to a transverse energy of...
We discuss the possibility that light new physics in the top quark sample at the LHC can be found by investigating with greater care well known kinematic distributions, such as the invariant mass $m_{bl}$ of the $b$-jet and the charged lepton in fully leptonic $t\bar{t}$ events. We demonstrate that new physics can be probed in the rising part of the $\textit{ already measured}$ $m_{bl}$...
We study the phenomenological viability of chiral extensions of the Standard Model, with new chiral fermions acquiring their mass through interactions with a single Higgs. We examine constraints from electroweak precision tests, Higgs physics and direct searches at the LHC. Our analysis indicates that purely chiral scenarios are perturbatively excluded by the combination of Higgs coupling...
We present a study of a scotogenic model addressing the dark matter problem while generating three non-zero neutrino masses. We investigate the dual nature of a dark matter candidate emerging from distinct particle components across diverse energy regimes within the energy range of HL-LHC. Results highlight the behavior of the dark matter candidate in varied energy contexts, with a focus on...
The Weinberg operator, the unique dimension-5 effective operator LLHH, can generate tiny Majorana masses for neutrinos. In the presence of new scalar multiplets acquiring vacuum expectation values (VEVs), novel Weinberg-like operators emerge, subsequently contributing to Majorana neutrino masses. We consider scenarios involving one or two new scalars transforming under higher SU(2)...
Understanding the flavour structure of leptons, i.e. their mass pattern and mixing, is a major unresolved puzzle in theoretical particle physics. In the recent past, a substantial effort went into models based on discrete flavour symmetries, but that approach proved to be particularly challenging. In 2017 a new promising direction was suggested: a “bottom-up” approach based on modular...
Within the framework of the Local Analytic Sector Subtraction we briefly present the method for removing infrared singularities at Next-to-Leading Order (NLO) in QCD for processes involving massless coloured particles either in the initial or in the final state. We present an extension of Local Analytic Sector Subtraction to the case involving massive emitter. This process also allows us to...
I present a probabilistically founded definition of theory uncertainties in perturbative computations due to the unknown higher orders. I show its performance against canonical recipes such as scale variation. I finally discuss future directions.
The need of percent precision in high energy physics requires the inclusion of QED effects in theoretical predictions, for example like the contributions coming from photon initiated processes. It is trivial then, to correctly determine the photon content of the proton.
In this work, we extend the NNPDF4.0 NNLO determination of parton distribution functions (PDFs) with a photon PDF,...
We include uncertainties due to missing higher order corrections to QCD computations (MHOU) used in the determination of parton distributions (PDFs) in the recent NNPDF4.0 set of PDFs. We use our previously published methodology, based on the treatment of MHOUs and their full correlations through a theory covariance matrix determined by scale variation, now fully incorporated in the new NNPDF...
We investigate the impact of theory uncertainties on a global EDM analysis in the low-energy sector. For this analysis, we employ SFitter as our tool of choice. In contrast to previous analyses, in the EDM sector, theory uncertainties are heavily contingent upon the model parameters and thus cannot be disentangled from the prediction as readily as for SMEFT global analyses.
Off-shell effects in large LHC backgrounds are crucial for precision predictions and, at the same time, challenging to simulate. We show how a generative diffusion network learns off-shell kinematics given the much simpler on-shell process. It generates off-shell configurations fast and precisely, while reproducing even challenging on-shell features.
Unfolding is a transformative method that is key to analyze LHC data. More recently, modern machine learning tools enable its implementation in an unbinned and high-dimensional manner. The basic techniques to perform unfolding include event reweighting, direct mapping between distributions and conditional phase space sampling, each of them providing a way to unfold LHC data accounting for all...
Deep generative models have emerged as a powerful paradigm for enhancing and maximising the potential for discovery at collider experiments. They can be deployed for multiple tasks, including fast simulations, data augmentation and anomaly detection. As novel methods continue to be developed, there is a pressing need to advance techniques for model selection and evaluation, particularly in...
Nowadays, the research in Beyond Standard Model (BSM) scenarios aimed at describing the nature of dark matter is a very active field. DarkPACK is a recently released software conceived to help to study such models. It can already compute the relic density in the freeze-out scenario, and its potential can be used to compute other observables.
The COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) experiment is a state-of-the-art cryogenic initiative in the field of dark matter direct detection. Operating at millikelvin temperatures and utilizing ultrapure NaI detectors, COSINUS employs a two-channel readout system utilizing transition edge sensors (TESs), allowing for effective particle...
SABRE aims to deploy arrays of ultra-low background NaI(Tl) crystals to carry out a model-independent search for dark matter through the annual modulation signature. SABRE will be a double-site experiment, made up of two ...
The elusive nature of dark matter has prompted innovative and open-minded experiments across a broad spectrum of energies employing high-sensitivity detectors, but despite the numerous attempts none has yielded up to now any evidence [1]. Inserted into this landscape is the Positron Annihilation into Dark Matter Experiment (PADME) at the Laboratori Nazionali di Frascati of INFN [2].
PADME...
In the last decades, the existance of dark matter (DM) has become one of the key elements of modern physics. Direct evidence of this exotic form of matter can be found by searching for extremely rare nuclear recoils of regular matter with energy of the order of few keV. The peculiar motion of the Earth around the centre of the Galaxy induces a strongly anisotropical structure in the angular...
In ecent years, we witnessed an increasing growth in the research of light Dark Matter (DM) candidates, addressing in particular axions and axion-like particles (ALPs). If axions are found to exist, they would untie the long-standing DM problem, after being originally postulated as a solution to the strong CP problem. The nature of a pseudoscalar, electrically neutral and feebly interacting...
Axion emission is known to be strongly constrained by neutrino-burst data from SN 1987A. Compton-like nucleon-pion to nucleon-axion scattering has recently been shown to be an important mechanism, due also to the large baryon densities involved. We perform a first quantitative study of the role of hadronic matter beyond the first generation -- in particular strange matter. We consistently...
We propose a comprehensive study of the Direct Detection phenomenology of singlet Dark Matter $t$-channel portal models. For that purpose, we present a complete computation of the loop induced direct detection cross-section for both scalar and fermionic Dark Matter candidates. We complete the study comparing the results with current and future bounds from Direct Detection experiments and...
First-order phase transitions, which take place when the symmetries are predominantly broken (and masses are then generated) through radiative corrections, produce observable gravitational waves and primordial black holes; also, if observed, they would signal new physics. I discuss a model-independent approach that is valid for large-enough supercooling to quantitatively describe these...
The QCD axion is the most robust explanation to the strong CP problem and provides a good dark matter candidate. A population of QCD axions can be produced in the early universe via scattering with SM particles, and can be searched for in cosmological datasets. I will present the state-of-the-art bound on the minimal QCD axion model by confronting momentum-dependent Boltzmann equations, from...
Confining QCD-like sectors are often present in BSM phenomenology. We critically reconsider the argument based on 't Hooft anomaly matching that aims at proving chiral symmetry breaking in 4d confining QCD-like theories with $N_c>2$ colors and $N_f$ flavors. We provide a detailed proof and clarify under which (dynamical) conditions the historical approach of $N_f$-independence holds, as a...
Scalar fields can be accidentally light if symmetries forbid their tree-level masses in the potential at the renormalizable level. We present some example models with small symmetry groups (typically SU(n) x U(1)) but with the scalars transforming in large representations. We discuss possible applications to generating natural hierarchies of scales in models with elementary scalars. In...
In this talk, I will review theoretical and phenomenological aspects of multi-loop amplitudes, focusing on the their wide range of physical applications. I will gently introduce the method employed in the calculation of the gg -> HH NLO SM and Beyond cross section to show where Feynman integrals enter, and where calculation bottleneck may arise.
The increasing mathematical understanding of...
Since the discovery of the Higgs boson, the ATLAS group at LNF has been studying its properties, particularly in the four-lepton decay channel. Known as the “golden channel,” this process played a crucial role in the discovery of the Higgs boson in 2012 and continues to be one of the primary final states for precise measurements of its properties, such as mass, spin/CP, and couplings with...
I will discuss the uncertainties due to the top-mass renormalization scheme allowing the trilinear Higgs boson self-coupling to vary around its Standard Model value including parton shower effects.
We consider a light scalar dark matter candidate with mass in the GeV range whose p-wave annihilation is enhanced through a Breit-Wigner resonance. The annihilation proceeds in the s-channel via a dark photon mediator. We compute the temperature at which kinetic decoupling between dark matter and the primordial plasma occurs and show that including the effect of kinetic decoupling can reduce...
Given the very large number of searches for resonances at the LHC, it comes as no surprise, statistically speaking, that excesses are occasionally observed in the data, that might or might not stand the test of time.
However, when these excesses are found to occur at the same invariant mass in different search channels, a theoretical interpretation becomes instructive. Indications for a...
