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Tag Archives: Evento scientifico

From kaonic atoms to strangeness in neutron stars

An updated review is presented of the theory of low-energy antikaon and hyperon interactions with nucleons and nuclear systems. Applications include kaonic hydrogen, recent calculations of kaonic deuterium and comparisons with K-p correlation functions from ALICE at LHC. This is followed by a discussion of the possible role played by kaons and hyperons in dense baryonic matter, with special emphasis on constraints provided by the existence of two-solar-mass neutron stars and garvitational wave signals of neutron star mergers.

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The ILC project – its physics and status

The international Linear Collider (ILC) is an electron-positron collider whose initial goal is to make precision measurements on the Higgs boson. Such measurements are expected to elucidate the shortcomings of the Standard Model of elementary particles and guide us to the new physics that governs the universe. Being a linear collider, It also has potential to upgrade its collision energy without sacrificing the investment up to that point.  In this talk, we review the scientific case of the ILC and describe its political status.

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MariX: Conceptual Design Report of a Multi-disciplinary Advanced Research Infrastructure for the generation and application of X-rays

The need of a fs-scale pulsed, MHz-class repetition rate, X-ray source for time-resolved fine analysis of matter (spectroscopy and photon scattering) in the linear response regime is addressed by the conceptual design of a facility called MariX, outperforming current X-ray sources based on FELs or Synchrotrons for the declared scope. MariX is based on the original design of a two-pass two-way superconducting linear electron accelerator, equipped with an arc compressor, to be operated in CW mode with up to 1MHz repetition rate. MariX provides FEL emission in the range 0.2-8 keV with up to 10^10 photons per pulse and up to 10^16 photons/s using a 1.5 GeV Linac, but delivering to the FEL undulators up to 3.8 GeV electrons. The accelerator complex includes an early stage that supports an advanced inverse Compton source of very high-flux hard X-rays (up to 10^13 monochromatic X-ray photon beams), of energies up to 180 keV, that are well adapted for large area advanced radiological imaging. Such a complex enables a broad science program and will serve a multidisciplinary user community, covering fundamental science of matter and application to life sciences, including health at preclinical and clinical level. MariX C.D.R. has been recently published on its dedicated web site: www.marix.eu.

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B-decay discrepancies: Where we stand after Moriond 2019

A whole set of B-decay data display persistent deviations with respect to the Standard Model (SM). Specifically, data hint at new effects in semi-leptonic interactions involving the b -> s and b -> c currents. Interestingly, the pattern of discrepancies after the recent Run-2 updates suggest well-defined effective-field theory (EFT) scenarios where the two sets of discrepancies, b -> s and b -> c, are related. In turn, such EFT picture finds a quantitative realization within well-defined UV-complete scenarios. I will provide a review of the whole subject, from data to the EFT picture to UV models.  

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Quantum Optical Control of Levitated Solids: a novel probe for the gravity-quantum interface

The increasing level of control over motional quantum states of massive, solid-state mechanical devices opens the door to an hitherto unexplored parameter regime of macroscopic quantum physics. I will report on our recent progress towards controlling levitated solids in the quantum regime. I will discuss the prospects of using these systems for fundamental tests of physics, including the interface between quantum and gravitational physics.

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Second Rome Physics Encounters @LNF

This informal meeting is the second of the Rome physics encounter series. It aims at bringing together young speakers working or collaborating with 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.

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Global fits to b → cτν transitions

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.  

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Some new ideas in Leptogenesis and Dark Matter studies

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.

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Daya Bay and JUNO Reactor Neutrino Experiments in China

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.

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The Belle II experiment at SuperKEKB

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.

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