The KLOE experiment was the first to exploit Initial State Radiation (ISR) processes to obtain the e+e− → π+π−(γ) cross section below 1 GeV. Three measurements have been published with small angle photon in the initial state: normalized using luminosity from Bhabha in 2005 and 2008 and using ππγ/μμγ ratio in 2014. An independent measurement with the large angle photon normalized to Bhabha has been published in 2011. These measurements are in good agreement, showing a good consistency among different analyses. A preliminary Gounaris-Sakurai fit of the pion form factor of the combined KLOE measurements is presented. We also discuss the γγ physics program of KLOE-2 experiment, made possible after the recent KLOE upgrade with new small angle tagging detectors along the DAFNE beam line. These detectors allow to detect the final leptons coming from process e+e− → e+e−γ ∗ γ∗ giving the possibility to measure the π0 → γγ decay and γ∗γ → π0 transition form factor. These measurements provide constraints to the models used to calculate the hadronic light-by-light contribution to the muon anomaly.
Results and prospects on hadronic cross section and γγ physics at KLOE/KLOE-2
MANDAGLIO, GIUSEPPE
Primo
Writing – Original Draft Preparation
2015-01-01
Abstract
The KLOE experiment was the first to exploit Initial State Radiation (ISR) processes to obtain the e+e− → π+π−(γ) cross section below 1 GeV. Three measurements have been published with small angle photon in the initial state: normalized using luminosity from Bhabha in 2005 and 2008 and using ππγ/μμγ ratio in 2014. An independent measurement with the large angle photon normalized to Bhabha has been published in 2011. These measurements are in good agreement, showing a good consistency among different analyses. A preliminary Gounaris-Sakurai fit of the pion form factor of the combined KLOE measurements is presented. We also discuss the γγ physics program of KLOE-2 experiment, made possible after the recent KLOE upgrade with new small angle tagging detectors along the DAFNE beam line. These detectors allow to detect the final leptons coming from process e+e− → e+e−γ ∗ γ∗ giving the possibility to measure the π0 → γγ decay and γ∗γ → π0 transition form factor. These measurements provide constraints to the models used to calculate the hadronic light-by-light contribution to the muon anomaly.Pubblicazioni consigliate
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