New ISR Cross Section Results on e + e − → π + π − π 0 π 0 and e + e − → π + π − η from BaBar

Se p 19 99 Production of the π − , π 0 in the reaction d ( e , pp ) e ′ π − π 0

Recently, the differential yield and target asymmetry of the reaction d(e, pp)eπ on the tensor polarized deuterium target have been presented in [1, 2], where the experimental procedure and basic assumption were described. A precise treatment of this reaction needs to investigate the reaction channels with an additional neutral pion production as a background to the leading reaction of a single...

5 Form Factor Fit for e + e − → π + π − π + π −

The cross section of e + e − → π + π − π + π − has been measured for center-of-mass energy from 0.6 GeV to 4.5 GeV by BABAR collaboration. We apply these experimental data to fit the theoretical cross section derived from the VMD(Vector Meson Dominance) model. At the same time, the relevant parameters have been deduced from the fitting, and the isovector form factor has also been obtained.

Results from NA 48 / 2 on ππ scattering lengths measurements in K ± → π + π − e ± ν and K ± → π 0 π 0 π ± decays

Observation of Z_{c}(3900)^{0} in e^{+}e^{-}→π^{0}π^{0}J/ψ.

Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Z_{c}(3900)^{0} with a significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2  MeV/c^{2} and 29.6±8.2±8.2  MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e^{+}e^{-}→π^{0}π^{0}J/ψ and the fr...

η → π + π − π 0 γ in Chiral Perturbation Theory