Measurement of the <i>e</i><SUP>+</SUP><i>e</i><SUP>-</SUP> → π<SUP>+</SUP> π<SUP>-</SUP> cross section between 600 and 900 MeV using initial state radiation


Ablikim M., Achasov M. N., Ai X. C., Albayrak O., Albrecht M., Ambrose D. J., ...More

PHYSICS LETTERS B, vol.753, pp.629-638, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 753
  • Publication Date: 2016
  • Doi Number: 10.1016/j.physletb.2015.11.043
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.629-638
  • Bursa Uludag University Affiliated: No

Abstract

We extract the e(+) e(-) -> 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 vertical bar F pi vertical bar(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,LO) (600-900 MeV) = (368.2 +/- 2.5(stat)+/- 3.3(sys)).10(-10), which is between the corresponding values using the BaBar or KLOE data. (C) 2015 The Authors. Published by Elsevier B.V.