Theoretical tools for new physics searches at a gamma gamma collider and the LHC

by G.J. GOUNARIS (Thessaloniki University)

Friday 3 Sept 1999, 14:00 → 14:15 Europe/Zurich

TH Auditorium (CERN)

1) It is shown that,in the Standard Model at energies above 250 GeV, the dominant amplitudes for the processes gamma gamma -> gamma gamma, gamma Z and ZZ, are helicity conserving and almost purely imaginary. This suggests using these processes at a gg Collider, for searching for New Physics characterized by largely imaginary amplitudes. As an example, we study the effects induced by possible SUSY particles, at energies above their production threshold. Such a study should be done in parallel with the study of the direct SUSY particle production, and should be very helpful in identifying the sparticle nature. 2) A new class of forward-backward asymmetries is constructed for V+jet (V=W, Z, gamma) production at a hadron Collider. These asymmetries should be measurable at LHC and the upgraded Tevatron, and should provide a new source of information on the gluon structure function of the proton.