arXiv subjects
Publications and source records attributed to Giulia Ricciardi.
We summarize selected up-to-date results related to semileptonic $B$ meson decays, namely results on the exclusive determination of the parameter $|V_{cb}|$ of the CKM matrix, on the inclusive determination of $|V_{ub}|$, and on $R(D^{(*)})$.
We briefly summarize up-to-date results on the determination of the parameters of the Cabibbo-Kobayashi-Maskawa matrix $|V_{cb}|$ and $|V_{ub}|$, which play an important role in the unitarity triangle and in testing the Standard Model, and recent results on semileptonic $B$ meson decays involving a $τ$ lepton.
We summarize the status of semileptonic and leptonic $B$ decays, including $|V_{cb}|$ and $|V_{ub}|$ exclusive and inclusive determinations, decays to excited states of the charm meson spectrum and decays into $τ$ leptons.
Flavour physics is currently well described by the Standard Model except for some measurements which could be signalling new physics. We briefly summarize the status of tensions in rare exclusive semi-leptonic $B$ decays and in $R_{K/D^{(\ast)}}$ ratios. We also address the issue of the long standing tension in the $|V_{cb}|$ and $|V_{ub}|$ exclusive/inclusive determinations.
We prove that the hierarchy of higher antibrackets (aka higher Koszul brackets, aka Koszul braces) of a linear operator $Δ$ on a commutative superalgebra can be defined by some universal formulas involving iterated Nijenhuis-Richardson brackets having as arguments $Δ$ and the multiplication operators. As a byproduct, we can immediately extend higher antibrackets to noncommutative algebras in a way preserving the validity of generalized Jacobi identities.
We discuss non-perturbative corrections to the neutrino sector, in the context of a D-brane Pati-Salam-like model, that can be obtained as a simple alternative to $SO(10)$ GUT's in theories with open and unoriented strings. In such D-brane models, exotic stringy instantons can correct the right-handed neutrino mass matrix in a calculable way, thus affecting mass hierarchies and modifying the see-saw mechanism to what we name exotic see-saw. For a wide range of parameters, a compact spectrum of right-handed neutrino masses can occur that gives rise to a predictive scenario for low energy observables. This model also provides a viable mechanism for Baryon Asymmetry in the Universe (BAU) through leptogenesis. Finally, a Majorana mass for the neutron is naturally predicted in the model, leading to potentially testable neutron-antineutron oscillations. Combined measurements in neutrino and neutron-antineutron sectors could provide precious informations on physics at the quantum gravity scale.
With the discovery of the Higgs boson the Standard Model has become a complete and comprehensive theory, which has been verified with unparalleled precision and in principle might be valid at all scales. However, several reasons remain why we firmly believe that there should be physics beyond the Standard Model. Experiments such as the LHC, new $B$ factories, and earth- and space-based astro-particle experiments provide us with unique opportunities to discover a coherent framework for many of the long-standing puzzles of our field. Here we explore several significant interconnections between the physics of the Higgs boson, the physics of flavour, and the experimental clues we have about dark matter.
Massive gravitational modes in effective field theories can be recovered by extending General Relativity and taking into account generic functions of the curvature invariants, not necessarily linear in the Ricci scalar R. In particular, adopting the minimal extension of f(R) gravity, an effective field theory with massive modes is straightforwardly recovered. This approach allows to evade shortcomings like ghosts and discontinuities if a suitable choice of expansion parameters is performed.
We summarize the status of $|V_{cb}|$ and $|V_{ub}|$ determinations, including the long standing tension among exclusive and inclusive determinations. We also discuss $B$ meson semileptonic decays to excited states of the charm meson spectrum and leptonic and semileptonic $B$ decays into final states which include $τ$ leptons.
We report on the current status of semi-leptonic $B_{(s)}$ decays, including rare decays, and the extraction of the absolute values of the CKM matrix elements $|V_{cb}|$ and $|V_{ub}|$.
We review the current status of the absolute values of the CKM matrix elements V(xb), with particular attention to latest determinations.
We review the current status of |V(cb)|, |V(ub)| and |V(tb)|, the absolute values of the matrix elements in the CKM third column.
We review recent progress in exclusive B --> D^(*) and inclusive B --> X(u) semileptonic B decays
We discuss the impact of recent progress in semileptonic D decays on light flavour spectroscopy and estimate mixing parameters in the eta-eta^prime system.
Semileptonic B and D decays are on a well deserved podium to extract CKM matrix elements, to validate theoretical tools and, more recently, even to look for hints of new physics. Here we review the latest updates.
We concisely review semileptonic B decays, focussing on recent progress on both theoretical and experimental sides.
We consider the see-saw mechanism within a non-supersymmetric SO(10) model. By assuming the SO(10) quark-lepton symmetry, and after imposing suitable conditions that ensure that the right-handed (RH) neutrino masses are at most mildly hierarchical (compact RH spectrum) we obtain a surprisingly predictive scenario. The absolute neutrino mass scale, the Dirac and the two Majorana phases of the neutrino mixing matrix remain determined in terms of the set of already measured low energy observables, modulo a discrete ambiguity in the signs of two neutrino mixing angles and of the Dirac phase. The RH neutrinos mass spectrum is also predicted, as well as the size and sign of the leptogenesis CP asymmetries. We compute the cosmological baryon asymmetry generated through leptogenesis and obtain the correct sign and a size compatible with observations.
The observation of CP violation effects is becoming more and more significant in a variety of channels, due to the impressive experimental effort of the last years. We review recent progress in Bs semileptonic decays and in Bs decays into CP eigenstates.