Anomalies in the flavor sector have attracted significant attention in recent years. Of particular interest for this talk are those in the muon and electron magnetic dipole moments: the so-called g-2 anomalies. The present status of these could point towards the requirement for new physics that couples differently to leptons and muons. I will review the status of scalar leptoquark models as...
In this talk, recent advances in the theoretical description of axions and their interactions are presented. We start by recalling the principle of reparametrization invariance, based on the Goldstone boson nature of the axion. Using this principle as a tool, we discuss first the axion coupling to gauge bosons, and show that they are actually not driven by the anomalies. Then we describe the...
We study the impact of running effects on QCD axion phenomenology. Focusing on variants of DFSZ model, it is possible to suppress simultaneously both the axion couplings to nucleons and electrons, realising the so-called astrophobic axion scenarios, wherein the tight bounds from SN1987A and from stellar evolution of red giants and white dwarfs are greatly relaxed. This suppsression is not...
I will discuss the possibility that the axion Peccei-Quinn symmetry is spontaneously broken after the beginning of inflation. This scenario interpolates between pre-inflationary and post-inflationary axion DM cosmology with significant phenomenological differences from both. In particular, large inflationary fluctuations are produced only at scales not constrained by CMB, avoiding the...
We discuss the current status of the exclusive $b \to c \ell\nu$ decay modes and review the situation with hadronic uncertainties as well as with the problems related to a reliable extraction of $|V_{cb}|$. We also discuss the lepton flavor universality both in the decays of mesons and in the decays of baryons, and emphasize the importance of studying the angular distribution of these decay...
We present our predictions for lifetimes, lifetime ratios and
semileptonic decay widths of single-charm (bottom) and double-charm
baryons within the Heavy Quark Expansion (HQE) framework, including all
known corrections. In contrast to earlier findings, our results
accommodate the experimentally-favoured hierarchy of the singly charmed
baryons. In the double-charm sector, we find a good...
In this talk, I will revisit the Standard Model (SM) predictions for $\mathcal{B}(B \to K^{(\ast)}\nu\bar{\nu})$ and discuss the opportunities that open up when combining its partial decay with that of $\mathcal{B}(B → K^{(\ast)}\mu\mu)$. I will argue that the differential measurement of $B \to K\nu\bar{\nu}$ decays allow for an useful cross-check of the shape of the vector form-factor...
Motivated by the direct discovery of gravitational waves (GWs) from black holes and neutron stars, there is a growing interest in investigating GWs from other sources. Among them, GWs from cosmic strings are particularly fascinating since they naturally appear in a large class of grand unified theories (GUTs). Remarkably, a series of pulsar-timing arrays (PTAs) might have already observed GWs...
We present the latest progress in analyzing the minimal potentially realistic non-supersymmetric $\mathrm{SO}(10)$ GUT model, whose scalar sector consists of representations $45+126+10$. Although the model is expected to give a robust proton decay prediction, any analysis is hampered by tachyonic instabilities present in the tree-level scalar potential. The one-loop corrected effective...
I will briefly discuss two ideas in dark matter model building. They first is that axion dark matter may be connected with neutrino mass generation, baryogenesis and flavour-dependent Higgs Yukawa couplings. The second arises within a continuing search for a good theory of the dark matter mass scale in the asymmetric dark matter paradigm. In particular, I will present some recent results on...
In this talk, we consider the phenomenology of electrically neutral complex vector particles V with a mass below the GeV-scale, but with higher dimensional form factor interactions to the SM photon. The astrophysics, cosmology and direct detection phenomenology will be presented.
The latest experimental results from CMS collaboration on Heavy Neutral Leptons will be presented. Various HNL production and decay modes are considered to guide the searches. The analysis of the full Run II data leads to stringent constraints on neutrino mass model parameters.
Direct searches at fixed target experiments and searches for neutrinoless double beta (0νββ) decay can be used to probe the Majorana vs. pseudo-Dirac nature of a Heavy Neutral Lepton (HNL) pair. Firstly, I will outline a phenomenological parametrisation relating the active-sterile mixing strengths to the neutrino oscillation data, assuming that the HNL pair generates masses for two light...
CP violation breaking is accidentally small in the SM: flavour invariants measuring CP violation in SMEFT are constructed and consequences on various flavour assumptions on their sizes are scrutinised.
The LHCb combined measurements of $\Delta a_{\rm CP} = a_{\rm CP} (D\to K^+K^-)- a_{\rm CP} (D\to \pi^+\pi^-)$ and $a_{\rm CP} (D\to K^+K^-)$ are in tension with predictions employing the Standard Model and U-spin symmetry of QCD. I discuss explanations in terms of new physics and propose test of these explanations in other $D$ decay modes.
Rare charm decays provide unique and complementary insights on flavor and BSM physics. We discuss status and progress in null test searches from theory on decays of charm mesons and baryons into invisibles, photons and leptons and where flavor experiments are currently pushing this frontier. We also discuss CP-violation together with sizable U-spin violation seen in hadronic 2-body decays.
In this talk I review vector-like quarks in leptons in flavour physics and EW precision observables in light of the W mass and the Cabibbo angle anomaly.
We emphasize the analogy between Vector-Like Quarks (VLQ) and Right Handed Neutrinos, illustrating how VLQ lead to naturally supressed FCNC and naturally small violations of 3x3 unitarity in the CKM matrix. VLQ provide a simple solution to the puzzle of eventual lack of unitarity in the first line of the CKM matrix and also provide a framework to have a realistic model with spontaneous CP...
We strengthen the cosmological bound on the axion mass, by solving the momentum-dependent Boltzmann equations for axion-pion scatterings and by using a phenomenological production rate derived from pion-pion scattering data, overcoming the breakdown of chiral perturbation theory. Using present cosmological datasets we obtain m_a < 0.24 eV. To further improve the bound and exploit the reach of...
We discuss examples of three Higgs doublet models which can provide good dark matter candidates. The emphasis is on models with S_3 symmetry, with or without spontaneous CP violation. Some aspects of the Weinberg potential will also be discussed.
I discuss the impact of triple-leptoquark interactions on matter stability for two specific proton decay topologies that arise at the tree- and one-loop level if and when they coexist. I furthermore demonstrate that the one-loop level topology is, in such an instance, much more relevant than the tree-level one despite the usual loop-suppression factor. To support that claim I present detailed...
Light quark Yukawa couplings are notoriously difficult to measure: the HL-LHC will be able to constrain the first generation couplings only by a factor of few hundred times their SM value.
I will discuss Higgs pair production and the Higgs off-shell measurement as potential probes of light quark Yukawa couplings. For the Higgs pair production process I will discuss also how interpretable...
We derive a closed-form false vacuum decay rate at one loop for a single real scalar field in the thin wall limit. We obtain the bounce solution, together with the Euclidean action, counter-terms and RG running, and we extract the functional determinant via the Gel’fand-Yaglom theorem. Our procedure is valid for a generic spacetime dimension D, and we provide an explicit finite renormalized...
I'll review the current state of affairs in Cosmology. Data from Planck and from Stage III spectroscopic and photometric experiments have firmly established the flat $\Lambda$CDM as the standard cosmological model. Many parameters are now measured with the percent level precision. Nevertheless, some tensions remain, the strongest being the Hubble parameter tension between expansion rate of the...
A non-minimal dark sector could explain why WIMP dark matter has evaded detection so far. Based on the extensively studied example of a simplified t-channel dark matter model involving a colored mediator, we demonstrate that the Sommerfeld effect and bound state formation must be considered for an accurate prediction of the relic density and thus also when inferring the experimental...
We critically analyse the future of composite dynamics via the impact of non standard model Higgs on the (non) observed g-2 and W-mass anomalies.
The ultimate dream of unification models consists in combining both gauge and Yukawa couplings into one unified coupling. This is achieved by using a supersymmetric exceptional ${\rm E}_6$ gauge symmetry together with asymptotic unification in compact five-dimensional space-time. The ultraviolet fixed point requires exactly three fermion generations: one in the bulk, and the two light ones...
I will discuss how dark matter long range interactions with itself or with the baryons leave unique signatures in precision cosmological observables. I will present exquisitely sensitive probes of these interactions in galactic surveys and in 21cm cosmology and discuss the challenges of the theory predictions.
Nuclear reactions in the solar core can produce light and weakly coupled beyond the standard model particles that subsequently reach the Earth. We analyze the second step of the proton-proton chain, and we investigate the flux of monochromatic 5.49 MeV massive spin-one particles. Focusing on two benchmark scenarios, which correspond to different communication mechanisms with the visible...
Sterile neutrinos are well-motivated extension of the Standard Model. In this talk I will focus on the interaction between sterile neutrinos and light active neutrinos through the magnetic moment portal. I will show that strong constraints can be derived from SN1987A through the non-observation of active neutrinos and photons produced from sterile neutrino decays. Furthermore, sensitivity...
The Tunneling Potential Formalism is an alternative to the Euclidean bounce for calculating tunneling actions, that control the decay of metastable vacua. In this talk I will discuss how this formalism can be extended to study other problems, from bubble-of-nothing decays to ungauged Q-balls and more.
The limitations of symmetry-based solutions to naturalness problems have led to seeking answers from the early universe. In this talk I will give an overview of cosmological solutions to naturalness problems, focusing on models of cosmological relaxation and self-organised localisation.
The Large Hadron Collider (LHC) at CERN has enabled us to explore the frontiers of particle physics and understand the fundamental nature of the universe. In this talk, I will present a comprehensive overview of high pT physics analyses conducted in Run 2 of the LHC by both the ATLAS and CMS experiments. These analyses cover a broad range of topics, including measurements of the Higgs boson,...
In the light of the current hints for new scalars at the LHC at 95 GeV and 151 GeV, I present an analysis of low mass resonances decaying into W bosons. Recasting and combining the SM Higgs analyses of ATLAS and CMS, our results give further support to the existance of such new Higgs bosons.
I will survey some recent applications of ML to the LHC and astrophysics, such as new methods for BSM searches and fast simulation at the LHC; and searching for stellar streams and measuring the local dark matter density using Gaia data.
Collinear radiation emitted from high-energy leptons can be resummed by solving the corresponding DGLAP equations, resulting in parton distribution functions (PDFs) for leptons. When going above the EW scale, all SM interactions should be considered and the inclusion of EW interactions bring several novel features that are not present in QCD PDFs of a proton. In this talk I will discuss our...
