Alexander Zaitsev

Study of

Dalitz plot of the

\eta'\to\eta\pi^+\pi^-

eta to etapi^+pi^-

Dalitz plot

decay is studied using the data collected with the VES spectrometer in two different exclusive reactions. The coefficients for the matrix element squared decomposition are measured on the largest statistics of

Evidence for a scalar meson resonance in the {pi}{sup -}p{yields}n{omega}{phi} reaction

eta

Study of the reaction π–A π+π–π– A at large statistics with VES setup

decays reported so far.

Recent results with upgraded VES setup: π−3π0 and other systems

The charge‐exchange reaction π−p→nω(780)φ(1020) is studied with the VES setup. The (ωφ) system is observed at relatively low background. Its invariant mass distribution peaks near threshold. The two‐particles partial wave analyses shows that the Jpcu2009=u20090++ state dominates. This wave is compared with 0++ component in the (ωω) system at the comparable mass, which was measured earlier.

Measurement of the f1(1285) → π+π−π0 decay

Partial wave analysis of the π–A π+π–π– system produced by 29 GeV/cπ– beam on a beryllium target is presented. About 30 × 106 |events in the wide t′|range 0–0.8 GeV2/c2 are collected with upgraded VES setup. The size of the data sample is 2.5 times larger than one previously analyzed by VES. Data are analyzed using formalism of the density matrix with unlimited rank. We discuss status of the a1(1420) a2(1700) a3(1875) states and a structure of exotic ρ(770)π P-wave with JPC = 1-+. Parameters of a3(1875) are estimated as M = 1985 ± 20 MeV/c2, Γ = 200 ± 50 MeV/c2 (preliminary).