Tag Archives: Evento scientifico

I will present the theoretical motivations for dark photons, vector bosons arising from a new U(1) gauge symmetry that kinetically mix with the photon. Such particles appear in a number of extensions of the Standard Model and can also be motivated from a purely effective field theory perspective as they provide one of the few portals to a dark sector. Such states have also found motivation in their ability to help explain astrophysical and terrestrial anomalies, such as the discrepant anomalous magnetic moment of the muon, and may also mediate interactions to light dark matter.

The seventeenth meeting of the Radio MonteCarlo WG (http://www.lnf.infn.it/wg/sighad) will be held at LNF on Monday and Tuesday, April 20th and 21st, 2015.

Fermilab is developing an Advanced Accelerator R&D program centered at IOTA – the Integrable Optics Test Accelerator. This small and flexible ring will be used for proof-of-principle R&D of novel concepts towards future high intensity machines. Of particular interest are the nonlinear integrable optics and the space charge compensation. This talk reviews IOTA’s R&D program as supported by modeling and simulations, and presents the current status of the design and construction of the facility.

The main results, presented during the NEUTEL 2015 conference held in Venice in the week 2-6 of March 2015, will be shown and discussed in the seminar.

Nucleon-antinucleon quasi-bound states, or states coupled to these, were searched for in the days of LEAR at CERN. Nothing has been found, but broad states or states close to the threshold were not excluded. Recent indications of the existence of quasi-bound states in the N$\overline N$ system will be presented. The BES collaboration has discovered a broad enhancement close to the p$\overline p$ threshold in the S wave, isospin 0 state formed in radiative decays of J$\psi$. Another enhancement located about 50 MeV below the threshold was found in mesonic decays of J$\psi$. In terms of the Paris potential model these findings are likely to be due to the same state. Antiprotonic atomic data provide some support for this interpretation and indicate existence of another fairly narrow quasi-bound state in a P wave. Few clarifying experiments will be indicated.

The existence of nuclear states of $\bar K$ mesons and $\eta$ mesons has been expected for about thirty years. The physical interest of this field is related to a new mechanism of nuclear binding generated by excitations of the internal nucleon structure. Despite being short lived such states might offer a new and interesting nuclear spectroscopy. Despite long and extensive experimental search, the existence and properties of such states are still elusive. Some similarities and related questions of the $\eta$ and $\bar K$ cases will be shown. Possible origin of the experimental difficulties related to weak production rate and large widths of such states will be discussed. I will try to indicate usefulness of the recent AMADEUS/KLOE measurements.

The workshop is intended to discuss the potentials for the future of the LNF infrastructures in the fields of Material Science and Applied Physics

The leading long distance quantum corrections to the Newtonian potential imply tiny but observable effects in the restricted three-body problem of celestial mechanics, i.e., at the Lagrangian libration points of stable equilibrium the planetoid is not exactly at equal distance from the two bodies of large mass, but the Newtonian values of its coordinates are changed by a few millimeters in the Earth-Moon system. We show that such a theoretical calculation is governed by a couple of quintic algebraic equation, whereas coordinates of collinear Lagrangian points are given in terms of the solution of an algebraic equation of ninth degree. We also discuss the prospects to measure, with the help of laser ranging, the above departure from the equilateral triangle picture, which is a challenging task. On the other hand, a modern version of the planetoid is the solar sail, and much progress has been made, in recent years, on the displaced periodic orbits of solar sails at all libration points, both stable and unstable. By taking into account the quantum corrections to the Newtonian potential, displaced periodic orbits of the solar sail at libration points are again found to exist.

After a brief review of the status of neutrino oscillation physics I discuss some phenomenological implications of neutrino mass in astroparticle setups as well as at the LHC and in cosmological missions.

We review the partial breaking of N=2 rigid Supersymmetry and present new results for mass generation in the SuperHiggs phase. Special Geometry,underlying the dynamics of vector multiplets and the symplectic Structure of electric-magnetic duality play an important role in this context