Tag Archives: Evento scientifico

We perform a general model-independent analysis of b → cτντ transitions, including measurements of RD , RD∗ , their q2 differential distributions, the recently measured longitudinal D∗ polarization FD∗, and constraints from the Bc → τντ lifetime, each L of which has significant impact on the fit. A global fit to a general set of Wilson coefficients of an effective low-energy Hamiltonian is presented, the solutions of which are interpreted in terms of hypothetical new-physics mediators. From the obtained results we predict selected b → cτντ observables, such as the baryonic transition Λb → Λcτντ, the ratio RJ/ψ, the forward-backward asymmetries AD(∗), FB the τ polarization asymmetries PD(∗) , and the longitudinal D∗ polarization fraction τ F D∗ . The latter shows presently a slight tension with any new-physics model, such L that an improved measurement could have an important impact.  

Type-1 seesaw is the simplest extension of the Standard Model (SM) that explains light neutrino masses and baryon asymmetry of the universe (BAU) via leptogenesis. In the first part of this talk, I shall discuss how different seesaw models can be visualised graphically and how a fine-tuning in the seesaw formula can be related to a Lorentz boost in the flavour space. I shall discuss a new parametrization of standard Casas-Ibarra orthogonal matrix and show how this new parametrisation is more useful in leptogenesis studies, particularly in SO (10) models. In the second part, I will show that an additional right handed (RH) neutrino could be a DM candidate in the two RH neutrino seesaw model if one considers the new one interacts with the other two with an effective dimension 5 operator induced by SM Higgs. This operator creates a temperature dependent matter potential and therefore the DM (the new RH neutrino) is produced from RH neutrino oscillation due to MSW-like matter effect even if the scale of new physics is post-Planckian. The operator responsible for DM production also causes the DM decay (to light neutrinos) and makes the scenario testable at neutrino telescopes such as IceCube.

Neutrino mass, shown by neutrino mixing and oscillation, is currently the only sign of new physics beyond the Standard Model (SM) of particle physics. In the completion of the three neutrino mixing angles, the Daya Bay Reactor Neutrino Experiment played a crucial and pioneering role in the measurement of the lastly known mixing angle θ13. Despite all the progresses in the last two decades in neutrino physics, we still only know the two mass-squared differences about neutrino mass, neither their absolute values nor the mass ordering. Due to the challenges in measuring the absolute masses, the neutrino mass ordering (NMO) is very likely to be the first experimental handle we could have on physics related to neutrino mass. With the success of the Daya Bay experiment and its contemporaries, it is now possible to resolve NMO using reactor neutrinos. Jiangmen Underground Neutrino Observatory (JUNO) was proposed to take the advantage of this principle to resolve NMO. In this talk, we will give a general review on neutrino physics, the discovery of neutrino oscillation and its recent experimental progresses, with the focus on Daya Bay and JUNO in China.

The Belle II experiment follows the path defined by the Belle and BaBar experiments, both of which started taking data about 20 years ago at the B-factories KEKB (Tsukuba, Japan) and PEP-II (SLAC, USA), respectively. Until now all measurements performed at B-factories are in agreement with the Standard Model; nowadays, however, there is compelling evidence for New Physics beyond the Standard Model from various sources. For this reason KEK has decided to upgrade the existing KEKB accelerator to deliver a 40 times higher peak luminosity which will allow to record a data sample 50 times larger with respect to its predecessor Belle. With such a data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa matrix with unprecedented precision and explore flavor physics in the beauty, charm and tau sectors. Belle II has also a unique capability, thanks to a new specialized trigger, to search for low-mass New Physics candidates. The Belle II experiment has recently started its data taking at the Upsilon(4S) resonance, and has recorded a data sample of about 6/fb of e+e- collisions. In this seminar, we will review the Belle II detector, the results of the first run and the physics prospects.

The goal of the meeting will be to discuss the current XLS injector designs and to establish an effective Injector Road Map for the preparation of the XLS CDR, identifying the options able to fulfill the XLS FEL requirements. All the injector designs developed so far  (S-C-X RF guns and DC gun)  will be compared in terms of capability to fulfill the target injector parameters at 300 MeV (at low and high repetition rates) as predicted by beam dynamics simulations. The Technology  Readiness Level (TRL) will be also considered. The meeting is foreseen to last 2.5 days. It will take place in FRASCATI at the INFN-LNF laboratories from 11 am on November 13 up to 1 pm of November 15.    

People have always been inspired by nature. Today we call biomimetic a kind of reverse engineering process of emulating natural time-tested (by evolution) patterns and strategies, incorporating solutions from the living world in products and solutions for all industries. Thus, biomimetic is the process of taking the solutions that exist in nature, mimicking them and applying them to technology. The talk focuses on the concept of biomimetic, describing how nature provides inspiration to scientists with some examples of applications that are used in everyday life, and my personal tentative of emulating nature lesson for developing intelligent (not only smart) engineering systems.

We will discuss some aspects of primordial black holes, such as how they may form in the early universe, why they may compose all dark matter, and how the Laser Interferometer Space Antenna (LISA) will be able to detect the associated gravitational waves. 

This informal meeting is the first of the Rome physics encounter series. It aims at bringing together young researchers working or collaborating within the research groups in the Rome area. In the spirit of workshops and conferences at LNF, talks will be presented in a pedagogical way and plenty of time is scheduled to allow discussions among participants. The encounters will be synchronised with a selected LNF General Seminar, held in the afternoon at 2.30pm. The lunch is offered to all registered participant at the LNF canteen.

The presence of kinetic mixing is an essential feature of any model that augments the Standard Model gauge symmetry with an additional U(1) symmetry . We look at the signal process, e+e− → γZ′ → γ+E/ at Belle-II, which is an outcome of this ubiquitous feature. We propose that the γ+E/ signal at the Belle-II detector will be a smoking gun for supersymmetry (SUSY) in the presence of a gauged U(1)Lμ−Lτ symmetry. A striking consequence of breaking the enhanced symmetry appearing in the limit of degenerate (s)leptons is the nondecoupling of the radiative contribution of heavy charged sleptons to the γ − Z ′ kinetic mixing. We take into account the severe constraints on gauged U(1)Lμ−Lτ models by several low-energy observables (like the muon (g − 2), data from the CCFR and BaBar collaborations, etc.) and show that any significant excess in all but the highest photon energy bin would be an undeniable signature of such heavy scalar fields in SUSY coupling to the Z′ gauge boson. The number of signal events depends crucially on the logarithm of the ratio of stau to smuon mass in the presence of SUSY. In addition, the number is also inversely proportional to the e+ − e− collision energy, making a low-energy, high-luminosity collider like Belle-II an ideal testing ground for this channel. This process can probe large swathes of the slepton mass ratio vs the additional gauge coupling (gX ) parameter space. More importantly, it can explore the narrow slice of MZ′ − …