Kawtar Hafidi, Physics Division, Argonne National Laboratory
Honey, I Shrunk the rho
Physics Division Colloquium - 19 May 2006

Because of the nature of the strong interaction, a hadron could hardly cross the nucleus without being absorbed. Yet if one shouts: "Honey, I shrunk the hadron," then this mini-hadron would be able to propagate freely through the nuclear medium. This property is well known in Quantum-Electro-Dynamics (QED): the interaction cross section of an electric dipole is proportional to its square size. As a result the cross section vanishes for objects with very small electric dipole moments. In Quantum-Chromo-Dynamics (QCD), the color is equivalent to the charge. By analogy to QED, the cross section of a color neutral dipole, as formed by a pair of oppositely colored quarks for instance, is also predicted to vanish for small sized hadron. This phenomenon is called Color Transparency (CT). In this talk, a historical overview of the experimental search for CT will be presented. The latest and upcoming experimental results will be discussed.

ANL Physics Division Colloquium Schedule