he KLOE experiment at the electron-positron collider DAΦNE uses the radiative return to measure the hadronic cross section σ(ee→ππ). The energy of DAΦNE is fixed at √{s}=M=1020 MeV, but the emission of one (or more) photons in the initial state (ISR) reduces the collision energy, allowing to cover the two-pion invariant mass M in the region from the two pion threshold to m. The precise measurement of this cross section is used to calculate the hadronic contribution to the muon anomaly a. A first measurement, in which the ISR-photon is detected at small polar angles, has already been performed at KLOE. Here we present the status of a complementary analysis at large photon polar angles. This allows to extend the measurement of the two-pion cross section to low masses below 600 MeV.
Measuring the Pion Form Factor via Radiative Return at large photon angles with KLOE
GORINI, Edoardo;PRIMAVERA, Margherita;VENTURA, Andrea;
2006-01-01
Abstract
he KLOE experiment at the electron-positron collider DAΦNE uses the radiative return to measure the hadronic cross section σ(ee→ππ). The energy of DAΦNE is fixed at √{s}=M=1020 MeV, but the emission of one (or more) photons in the initial state (ISR) reduces the collision energy, allowing to cover the two-pion invariant mass M in the region from the two pion threshold to m. The precise measurement of this cross section is used to calculate the hadronic contribution to the muon anomaly a. A first measurement, in which the ISR-photon is detected at small polar angles, has already been performed at KLOE. Here we present the status of a complementary analysis at large photon polar angles. This allows to extend the measurement of the two-pion cross section to low masses below 600 MeV.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
