Initial-state radiation measurement of the e^+e^- → π^+π^-π^+π^- cross section
We study the process e^+e^-→π^+π^-π^+π^-γ, with a photon emitted from the initial-state electron or positron, using 454.3 fb^(-1) of data collected with the BABAR detector at SLAC, corresponding to approximately 260 000 signal events. We use these data to extract the nonradiative σ(e^+e^-→π^+π^-π^+π^-) cross section in the energy range from 0.6 to 4.5 GeV. The total uncertainty of the cross section measurement in the peak region is less than 3%, higher in precision than the corresponding results obtained from energy scan data.
Additional Information© 2012 American Physical Society. Received 10 February 2012; published 21 June 2012. We are grateful for the extraordinary contributions of our PEP-II colleagues in achieving the excellent luminosity and machine conditions that have made this work possible. The success of this project also relies critically on the expertise and dedication of the computing organizations that support BABAR. The collaborating institutions wish to thank SLAC for its support and the kind hospitality extended to them. This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l'Energie Atomique and Institut National de Physique Nucléaire et de Physique des Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Educaciόn y Ciencia (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A. P. Sloan Foundation.
Published - Lees2012p18786Phys_Rev_D.pdf