Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR

TL;DR

This study measures the cross section of the e+e- --> pi+ pi- pi0 process using initial state radiation at BABAR, providing insights into meson decays and branching fractions within the 1.05 to 3.00 GeV energy range.

Contribution

First measurement of the e+e- --> pi+ pi- pi0 cross section using initial state radiation at BABAR, including branching fractions for omega, phi, and J/psi decays.

Findings

Measured branching fractions for omega and phi mesons.

Evaluated the e+e- --> pi+ pi- pi0 cross section from 1.05 to 3.00 GeV.

Determined the J/psi --> pi+ pi- pi0 branching fraction.

Abstract

The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range 1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18 +/- 0.19)% has been measured.