Precision measurement of $\sigma (e^+ e^-\rightarrow\pi^+\pi^-\gamma)/\sigma (e^+ e^-\rightarrow\mu^+\mu^-\gamma) $ and determination of the $\pi^+\pi …
D Babusci, D Badoni, I Balwierz-Pytko… - arXiv preprint arXiv …, 2012 - arxiv.org
arXiv preprint arXiv:1212.4524, 2012•arxiv.org
We have measured the ratio $\sigma (e^+ e^-\rightarrow\pi^+\pi^-\gamma)/\sigma (e^+ e^-
\rightarrow\mu^+\mu^-\gamma) $, with the KLOE detector at DA $\Phi $ NE for a total
integrated luminosity of $\sim $240 pb $^{-1} $. From this ratio we obtain the cross section
$\sigma (e^+ e^-\rightarrow\pi^+\pi^-) $. From the cross section we determine the pion form
factor $| F_\pi|^ 2$ and the two-pion contribution to the muon anomaly $ a_\mu $ for $0.592<
M_ {\pi\pi}< 0.975$ GeV, $\Delta^{\pi\pi} a_\mu $= $({\rm 385.1\pm1. 1_ {stat}\pm2. 7_ {sys+ …
\rightarrow\mu^+\mu^-\gamma) $, with the KLOE detector at DA $\Phi $ NE for a total
integrated luminosity of $\sim $240 pb $^{-1} $. From this ratio we obtain the cross section
$\sigma (e^+ e^-\rightarrow\pi^+\pi^-) $. From the cross section we determine the pion form
factor $| F_\pi|^ 2$ and the two-pion contribution to the muon anomaly $ a_\mu $ for $0.592<
M_ {\pi\pi}< 0.975$ GeV, $\Delta^{\pi\pi} a_\mu $= $({\rm 385.1\pm1. 1_ {stat}\pm2. 7_ {sys+ …
We have measured the ratio , with the KLOE detector at DANE for a total integrated luminosity of 240 pb. From this ratio we obtain the cross section . From the cross section we determine the pion form factor and the two-pion contribution to the muon anomaly for GeV, = . This result confirms the current discrepancy between the Standard Model calculation and the experimental measurement of the muon anomaly.
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