• Browse all
Measurement of the $e^+ e^− \to \pi^+ \pi^−$ cross section between 600 and 900 MeV using initial state radiation

The BESIII collaboration
Phys.Lett.B 753 (2016) 629-638, 2016.

Abstract
We extract the $e^+e^-\rightarrow \pi^+\pi^-$ cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb$^{-1}$ taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor $|F_\pi|^2$ as well as the contribution of the measured cross section to the leading order hadronic vacuum polarization contribution to $(g-2)_\mu$. We find this value to be $a_\mu^{\pi\pi,\rm LO}(600-900\;\rm MeV) = (368.2 \pm 2.5_{\rm stat} \pm 3.3_{\rm sys})\cdot 10^{-10}$.

  • Bare Cross Section

    10.17182/hepdata.73898.v4/t1

    Bare cross section $\sigma^\mathrm{bare}(e^+e^-\to\pi^+\pi^-(\gamma_\mathrm{FSR}))$ of the process $e^+e^-\to\pi^+\pi^-$ measured using the initial state radiation method. The data is corrected concerning...

  • Covariance Matrix of the Bare Cross Section

    10.17182/hepdata.73898.v4/t2

    Statistical covariance matrix of the bare cross section $\sigma^\mathrm{bare}(e^+e^-\to\pi^+\pi^-(\gamma_\mathrm{FSR}))$.

  • Pion Form Factor

    10.17182/hepdata.73898.v4/t3

    Pion form factor $|F_\pi|^2$ measured using the initial state radiation method. The data is corrected concerning vacuum polarization effects.

  • Covariance Matrix of the Pion Form Factor

    10.17182/hepdata.73898.v4/t4

    Statistical covariance matrix of the pion form factor $|F_\pi|^2$.

Version 4 modifications: fix some entries

Loading Data...

Ask a Question


Your question will be emailed to those involved with the submission. Please mention the relevant table.


Please log in to HEPData to send a question.