Tag Archives: Evento scientifico

I will discuss a simple QCD axion model that arises from identifying Peccei-Quinn with Froggatt-Nielsen symmetries. The flavor problem of the Standard Model is addressed by a U(1) flavor symmetry, which naturally leads to an axion that solves the strong CP problem. The ratio of the axion mass and its coupling to photons is related to SM fermion masses and predicted within a small range, as a direct result of the observed fermion mass hierarchies. The same hierarchies determine the axion couplings to fermions, making the framework very predictive and experimentally testable by future axion and precision flavor experiments.

I will discuss my recent achievements in researches on dark dark matter and flavour anomalies.

One of the main problems of axion scenarios is to explain the origin of an almost exact Peccei-Quinn symmetry only broken by the QCD anomaly. In this talk I will present several models where the QCD axion arises accidentally. This can be realised in confining gauge theories where the Peccei-Quinn symmetry can emerge accidentally if the representations are chiral. In some cases these models can be understood as the deconstruction of 5-dimensional gauge theories but more general constructions are possible. Phenomenological features will be discussed.

                                                  During the Symposium the strange and non-strange mesons induced processes studies at the DAFNE collider at LNF-INFN, Italy, and at the J-PARC and RIKEN facilities in Japan will be discussed in a unitary framework. The experimental research is focused on several complementary key processes, resulting either from stopped or low-energy kaon induced reactions at the DAFNE collider, from high-energy kaons induced reactions at J-PARC to pionic atoms studied at RIKEN. Studies of kaonic atoms and pionic atoms , of the hyperon-nucleon interactions, as well as the search for deeply bound kaonic nuclear states deliver new constraints on the antikaon-nucleon/nuclei and pion-nucleon/nuclei interactions. Taking advantage of advanced detector systems, such as high precision X-ray detectors, active targets, trackers and calorimeters, and considering the opportunity to use the Italian and Japanese facilities in the coming years, we face the unique chance for resolving the ambiguities and shed new light on the structure of the neutron stars and arrive to a new understanding of the role of strangeness in the Universe. The Symposium is organized with the support of the StrangeMatter (Strangeness in the compact stars? High precision experimental and theoretical studies of the strange matter nuclear interactions at low-energies) project, financed by the Ministero degli Affari Esteri e della Cooperazione Internazionale, Direzione Generale per la Promozione del Sistema Paese.   Organizers: Catalina Curceanu, LNF-INFN (Chair) Kenta Itahashi, RIKEN (Japan) Masahiko Iwasaki, RIKEN (Japan) Fuminori Sakuma, RIKEN (Japan) Alessandro Scordo, LNF-INFN (Italy) Johann Zmeskal, SMI-Vienna (Austria)  

This seminar reviews recent theoretical developments in the study of charged lepton flavour violation. The first part illustrates the status of precise next-to-leading order quantum electrodynamics calculations for the background of charged lepton flavour-violating processes, with a focus on the muonic “rare” and “radiative” decays. Phenomenological implications of these computations and their impact on present and future experiments will be discussed. The second part describes the recent progress in the effective field theory interpretation of charged lepton-flavour violating observables in connection with different energy scales. A systematic approach is briefly presented and applications on muonic and tauonic observables are reported.

A new design of thermal neutron irradiation facility, called HOTNES (HOmogeneous Thermal NEutron Source), was prototyped within the INFN-LNF / ENEA-Frascati collaboration. HOTNES is a polyethylene assembly, with about 70 cm × 70 cm square section and 100 cm height, including a large, cylindrical cavity with diameter 30 cm and height 70 cm. The facility is supplied by a 241Am-B source located on the cavity bottom. A specially studied combination of reflecting and attenuating parts produces constant values of fluence rate over irradiation planes as large as 30 cm in diameter. By varying the irradiation plane, the thermal fluence rate can be varied from about 700 cm-2 s-1 to 1000 cm-2 s-1. The facility design, previously optimized by Monte Carlo simulation, was experimentally verified. The main features of the HOTNES facility and the neutron field characterization will be presented.

The HOmogeneous Thermal NEutron Source (HOTNES) is a new type of thermal neutron irradiation assembly developed by the ENEA-INFN collaboration. The facility was fully characterized in terms of neutron field and dosimetric quantities, by either computational and experimental methods. The results of the first “HOTNES users program”, carried out in 2016, and covering a variety of thermal neutron detectors such as scintillators, solid-state, single crystal diamond and gaseous detectors will be presented and the future perspectives outlined.

A selection of the most recent results from the CMS experiment will be presented. The results are based on the analysis of the proton-proton (pp) collision data delivered by the LHC in year 2016, at an energy of 13 TeV in the pp centre of mass system, corresponding to an integrated luminosity of about 40/fb. The LHC and CMS performance will be briefly described. The latest updated results on the standard model (SM) precision measurements for the scalar and top sectors will be first presented. It includes the new H scalar property measurements from the 4 lepton decay channel and the 3 sigma evidence for the ttH coupling, in the multi lepton final states. In the second part, the latest results on the searches for new physics beyond the SM will be presented, including searches for dark matter particles.

The $eta$ meson is almost unique in the particle universe since it is a Goldstone boson and the dynamics of its decay are strongly constrained. Because the eta has no charge, decays that violate conservation laws can occur without interfering with a corresponding current. The integrated eta meson samples collected in earlier experiments have been less than ~$10^8$ events, limiting considerably the search for such rare decays. Only recently, WASA-at-Cosy produced about 10^9 eta, starting to breach into new physics. A new experiment, REDTOP, is being proposed to the scientific community with the intent of collecting more than $10^{13}$ triggers/year for studies of rare $eta$ decays. Such statistics are sufficient for investigating several symmetry violations, and for searches for new particles beyond the Standard Model. The physics program, the accelerator systems and the detector for REDTOP will be discussed during the colloquium.