e+ e- -> phi [pi pi]_{I=J=0} in UCHPT and the new resonance X(2175).

por Mauro Napsuciale (IFIC)

viernes 25 may. 2007 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

We present results for e+ e- annihilation into phi pi pi, with the pi pi pair in an isoscalar s-wave, within unitarized chiral perturbation theory. This process is induced at one loop level in this framework and we use the unitarized kaon form factor instead of the lowest order terms in order to account for the high virtuality of the exchanged photon. We also study effects of vector mesons (K*) in the loops taking into account effects of heavy vector mesons in the K*K transition form factor. As a result, for dipion invariant mass close to the f0(980) pole we obtain a proper description of events in the background of recent BABAR data for e+ e- ->phi f0 but not of the resonant events around sqrt(s)= 2175 MeV. We finally discuss the possibility of a three body structure for this resonance.