arXiv subjects
Publications and source records attributed to Luciano Maiani.
Exotic charmonium and bottonomium resonances recently discovered are discussed and interpreted as diquark-antidiquark states containing a pair of charm quarks and a pair of light, up and down, quarks. Successes, shortcomings and predictions of the model are illustrated.
Universality of the weak interactions is reviewed, with special emphasis on the origin of the Cabibbo theory of strange particles beta-decays and its role in the discovery of the unified Electroweak Theory. Achievements and present challenges of the Standard Theory of particles interactions are briefly illustrated. As an homage to Nicola Cabibbo, his leading role in the Roma school of theoretical physics and in the italian science in general is reviewed.
The GIM Mechanism was introduced by Sheldon L. Glashow, John Iliopoulos and Luciano Maiani in 1970, to explain the suppression of Delta S=1, 2 neutral current processes and is an important element of the unified theories of the weak and electromagnetic interactions. Origin, predictions and uses of the GIM Mechanism are illustrated. Flavor changing neutral current processes (FCNC) represent today an important benchmark for the Standard Theory and give strong limitations to theories that go beyond ST in the few TeV region. Ideas on the ways constraints on FCNC may be imposed are briefly described.
We discuss the general decomposition and possible general parameterizations of the processes $e^+ e^- \to γ^* \to P_1 P_2 γ$, where $P_1 P_2=π^0 π^0$, $π^0η$, or $π^+π^-$, for $\sqrt{s}\approx M_Φ$. Particular attention is devoted to the amplitude where the two pseudoscalar mesons are in a $J^{CP}= 0^{++}$ state, where we propose a general parameterization which should help to shed light on the nature of light scalar mesons.
Some features and predictions of a recently proposed model based on diquark-antidiquark bound states are illustrated. Its ability in accomodating newly discovered charmed resonances around 4 GeV is discussed.