Erratum: Thee+e−→2(π+π−)π0,

B. Aubert¹,

M. Bona²,

D. Boutigny³

et al.

Abstract

We study the processes e + e − → 2(π + π − )π 0 γ, 2(π + π − )ηγ, K + K − π + π − π 0 γ and K + K − π + π − ηγ with the hard photon radiated from the initial state. About 20000, 4300, 5500 and 375 fully reconstructed events, respectively, are selected from 232 fb −1 of BABAR data. The invariant mass of the hadronic final state defines the effective e + e − center-of-mass energy, so that the obtained cross sections from the threshold to about 5 GeV can be compared with corresponding direct e + e − measurements, currently available only for the ηπ + π − and ωπ + π − submodes of the e + e − → 2(π + π − )π 0 channel. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from e + e − → ω(782)π + π − and study the ω(1420) and ω (1650) resonances. In the charmonium region, we observe the J/ψ in all these final states and several intermediate states, as well as the ψ(2S) in some modes, and we measure the corresponding branching fractions.

Hadron production viae+e−collisions with initial state radiation

“…K þ K À þ À was also studied by BABAR (Aubert et al, 2007c). The measured cross section is small and rises from threshold to a maximum value of about 0.2 nb at 2.8 GeV, followed by a monotonic decrease with increasing energy.…”

“…The clear signal of the 0 ð958Þ intermediate state is observed in the K þ K À and þ À mass distributions. Unfortunately, the 0 ð958Þ invariant-mass spectrum is not shown in Aubert et al (2007c). This spectrum is interesting since for the four-quark Yð2175Þ resonance (see Sec.…”

“…For the process e þ e À ! 2ð þ À Þ 0 (Aubert et al, 2007c) in the mass region of the J=c and c ð2SÞ mesons discussed in Sec. V, the value of the mass resolution obtained from the fit to the J=c spectrum is about 9 MeV=c 2 , in good agreement with MC simulation.…”

“…V) the mass calibration is performed at the J=c mass. The difference between the measured and nominal (Eidelman et al, 2004) J=c masses is found to be less than 1 MeV=c 2 [see, for example, Aubert et al (2007cAubert et al ( , 2008b]. For the 3 final state the mass scale shift was determined at the !-and -meson masses (Aubert et al, 2004b) m !…”

“…The BABAR detector studied a number of ISR reactions with five hadrons in the final state: 2ð þ À Þ 0 , 2ð þ À Þ, K þ K À þ À 0 , and K þ K À þ À (Aubert et al, 2007c).…”