Today I spent the better part of the afternoon in the company of 150 high-school students at the Liceo Fermi in Padova, giving a seminar on particle physics in the context of a project called "Masterclasses" which has been active since 2005 and is a big success.

The project aims at students in the last years of their high school and attempts to involve them in the experiments undergoing at the CERN laboratories. Sets of lectures on particle physics and cosmology at the schools are followed by a "hands-on" session at the Physics Department, where students are taught and then tested in recognizing heavy particle decays from event displays.

Next Sunday Italians will vote to change the composition of the two houses of parliament: the "lower" Camera dei Deputati and "upper" Senato della Repubblica. And as often happens with Italian politics, things are complicated. So, despite this site is mostly visited for other reasons than trivialities about politics in foreign countries, I thought I would provide here my own short-sighted, biased panorama of the situation.

Every two years physicists and astrophysicists who work in the area of neutrino physics get together in the wonderful setting of Palazzo Franchetti, a historical palace on the Canal Grande in Venice, Italy, to discuss the latest results of experiments and theoretical ideas, and to plan for the future.

Quite some time ago I discussed here the tentative Y(4140) resonance  claimed by the CDF collaboration in their Run II data. This was a peak which was found in B-decay data containing a J/Psi signal, a phi meson, and an additional kaon track, and it resulted from the  study of the mass difference of the J/Psi + phi signal and the J/Psi alone.

Confused ? You have all rights to be. I will explain everything in good order, but be sure that the matter was puzzling not only for laymen but also for insiders: because the find was mysterious, not predicted by existing models, and potentially controversial.

B Decays and the CDF Claim

The Omega_b particle is a quite peculiar baryon, made up by three heavy quarks: a b-quark, and two s-quarks. Because of this composition, where only down-type quarks appear, the phenomenology of the decay of this particle is really spectacular: both the b-quark and the strange quarks take quite some time to decay, and as they take shifts to do it the Omega_b first transmutes into a Omega (a particle made up by three s-quarks!), then into a Lambda, and finally into a proton.

Each of these decays generates a reconstructable decay point, so one can reconstruct the whole chain perfectly. A sketch will clarify matters - see below.