Timelike Form Factors of Pions, Kaons and other Hadrons

by Prof. Kamal SETH (Northwestern University)

Wednesday 3 Jul 2013, 15:00 → 17:00 Europe/Rome

Aula Bruno Touschek (LNF INFN)

Electromagnetic form factors of hadrons provide the most transparent insight into the quark-gluon structure of hadrons. Since only nucleons are available as possible targets, spacelike form factors can only be determined for them by elastic scattering of electrons. On the other hand, timelike form factors can be determined for any hadrons by means hadron-antihadron formation in electron-positron annihilation. This has become possible with sizable beams which have become available in colliders, and the first measurements are being reported recently. Theoretical understanding of these measurements in terms of QCD is in principle possible for large momentum transfers where perturbative methods can be used. We have made the world's first measurements of the timelike form factors of the most elementary of all mesons, the pion and the kaon at the highest possible momentum transfers from 14 GeV^2 to 18 GeV^2 with high precision. The form factor results,, and their implications for SU(3) breaking will be discussed in terms of perturbative QCD predictions. Time permitting I will throw in our results for the first measurements of hyperon form factors which have not been measured ever before.

Slides 2013-Frascati.pdf