Tag Archives: Evento scientifico

The hierarchy problem of the Standard Model of particle physics might have a cosmological solution based on relaxion models, an idea recently put forward. In my talk I first review the basics of this mechanism and then discuss whether the relaxioncould also play the role of the inflaton.

Since the early 90’s it was understood that in order for the Peccei Quinn (PQ) mechanism to work the global U(1)_PQ had to be realized to an extremely high level of accuracy. In fact, even a tiny explicit breaking of the global PQ symmetry (e.g. via Planck-induced effective operators) would sizably contribute to the axion vacuum energy density and prevent the θ angle to relax to a value below the experimental upper bound |θ| < 10^-10. In this contribution, I will reproduce the standard argument and review possible mechanisms in order to protect the axion.

Recently, two SUSY GUTs of flavour have been proposed, based on SU(5) and SO(10) with non-Abelian flavour symmetry. They are reasonably complete, resolving many outstanding problems in GUT model building; as a result, they are rather involved. I am currently working on constructing the minimal and most predictive viable SO(10) model within this framework, with a focus on producing the correct masses and mixings for quarks and leptons. This may be combined with a Peccei-Quinn (PQ) symmetry to resolve the strong CP problem, giving a “flavoured PQ” GUT model. Within this framework, one might explore SUSY and/or axion phenomenology.

Hitherto, the laser has been very successful to study atomic physics. The possibility to amplify lasers to extreme peak power offers a new paradigm unifying the atomic and subatomic worlds, to include Nuclear physics, High Energy Physics, Astrophysics and Cosmology. This application needs extreme intensities. At the moment we are experiencing a rush toward the 10 PW led by the 3-pillar ELI infrastructure along with Apollon in France and similar infrastructures in Russia, USA, China and Korea. One of the most intriguing applications is the possibility to produce extraordinary large gradients in the TeV/cm regime or 1000 times what is possible with LWA in the visible. Also we will discuss what the generation of GeV protons with numerous applications in proton therapy, short-lived isotope production, nuclear waste transmutation and the like.

The relativistic mean-field (RMF) models either with higher order couplings or density-dependent couplings can be used to explain neutron stars properties with and without kaon or baryons. The nuclear interactions are described by the exchange of the sigma, omega and rho mesons. RMF parameterizations consistent with the recently studied constraints related to nuclear matter, pure neutron matter and symmetry energy were used to calculate the equations of state of star. The properties of nonrotating and rotating neutron stars are considered for a set of equations of state.

Aim of the workshop: This meeting aims at gathering theorists and experimentalists working in the Rome area in the field of collider physics. In an informal environment, we shall discuss several issues, which are relevant at present (SPS and LHC) and future accelerators. In particular, we shall debate the hunting for new physics with the NA62 detector, the coupling of the Higgs boson to gluons and top quarks, top-Higgs associated production and discuss the physics of future facilities, such as ILC and FCC, in both hadron-hadron and electron-positron modes.

The top quark plays a central role in many LHC analyses that test the Standard Model and that search for new physics. I will review why this is so, and discuss in particular recent advances in how to describe the top quark production and decay processes precisely, including the spin of the top quark, and with possible new physics influences. Recent experimental results and theoretical advances will be reviewed, and an outlook given.

Aim of the workshop: In spite of its consolidated experimental success, the standard model of particle physics falls short of describing all observed phenomena. For instance, the cosmological matter/antimatter asymmetry, dark matter, neutrino masses, all require some extension of the standard model. Well motivated theoretical considerations also support the expectation that physics beyond the standard model should sooner or later show up. Presently, it is far from clear which directions should be taken to extend the theory, and while the high energy frontiers keep being explored at the LHC, it is important to maintain under attentive scrutiny any discrepancy between theory predictions and experimental results. In this 3-day workshop we plan to review the status of a few particle physics puzzles of different typologies: long-standing unresolved issues awaiting for further experimental clarification (muon g-2, neutrino physics anomalies), recent hints of anomalies in specific measurements where signals of new physics might preferentially show up (bottom and top physics), and discrepancies particularly robust, which cannot be ascribed to statistical fluctuations (internal e+e- production in 8Be nuclear transitions, proton charge radius). We plan to have only two or three talks each day, and plenty of time to jointly reanalyse the status of the various issues, confront and discuss strategies and ideas. The general approach and format of the talks (on invitation only) will be pedagogical, and should favor extended interaction among participants. Scientific Program and Speakers:  Javier Virto  (Bern) "Flavor anomalies in B physics" Andrea Giammanco (Louvain, CP3) "Who ordered that? Investigations of the …

A possibility that the spin-statistics theorem is broken in neutrino physics is discussed. The impact of such violation on double beta decay, big bang nucleosynthesis, and the cosmological dark matter problems are considered. A possible transition of the statistics breaking from the neutrino sector to other particles is estimated.