AbstractResults of the partial-wave analysis of the reactionπ−p→π+π−π0n, studied at % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWexLMBb50ujb% qeguuDJXwAKbacfiGae8hCaa3aaSbaaSqaaGqaciaa+b8adaahaaad% beqaaGGaaiab9jHiTaaaaSqabaGccqGH9aqpcaaIZaGaaGOnaerbbj% xAHXgaiyaacaaFGaacbaGaaS3raiaa7vgacaWEwbGaaS3laiaa7nga% aaa!4821! $$p_{\pi ^ - } = 36 GeV/c$$ on 2·105 event statistics, are presented. Masses and widths ofa2(1320) andω3(1670) mesons are measured, as well as differential cross-sectionsdσ/dt in thea2 andω3 regions. It is shown that the relative phase between 2+ and 3− is consistent with the two-resonance description. The estimated limits for theπ0(1300),π2(1670),ω1(1420) andω1(1600) cross sections are also presented.

Results of the partial-wave analysis of the reaction pi(-)p --> pi(+)pi(-)pi(0)n, studied at p(pi-) = 36 GeV/c on 2 . 10(5) event statistics, are presented. Masses and widths of a(2)(1320) and omega(3)(1670) mesons are measured, as well as differential cross-sections d sigma/dt in the a(2) and omega(3) regions. It is shown that the relative phase between 2(+) and 3(-) is consistent with the two-resonance description. The estimated limits for the pi(0)(1300), pi(2)(1670), omega(1)(1420) and omega(1)(1600) cross sections are also presented.

We present here the results of the VES experiment obtained in 1992–1993: 1) The partial-wave analysis (PWA) has been performed for the reactions\(\pi ^ - \mathcal{N} \to \eta \pi ^ - \mathcal{N}\) and\(\pi ^ - \mathcal{N} \to \eta \pi ^ - \mathcal{N}\). It has been shown that the intensity of the exotic wave withJPC=1−+ for the η′π- system significantly exceeds that for the ηπ- system. 2) The PWA has been performed for the reactions\(\pi ^ - \mathcal{N} \to \pi ^ + \pi ^ - \pi ^ - \mathcal{N}\) and\(\pi ^ - \mathcal{N} \to {\rm K}^ + {\rm K}^ - \pi ^ - \mathcal{N}\). The resonance atm=1.8 GeV withJPC=0−+ is clearly seen in both reactions. 3) The radiative decay f1→π(770)γ has been studied. The measured BR(f1(1285)→p0(770)γ)=(3.0±0.7(stat)±0.6(syst))·10-2.

The reaction π− A → K+K−π− A was studied at the momentum of 37 GeV/c on the beryllium target at the wide aperture VES spectrometer. The partial-wave analysis of the K+K−π− system produced at low |t′| < 0.08 GeV2 was performed. It is shown that in the wave with JP = 0− there exists an object withmass 1.79±0.014 GeV/c2 and width 0.21±0.07 GeV/c2 decaying into κK− and |0(975)π−.

A partial-wave analysis of the ηπ− and η′π− systems produced in the reactions π−N→η(η′)π−N on a berylium target at a beam momentum of pπ− = 37 GeV/c is performed. It is shown that (1) all the waves with negative exchange naturality are negligibly small for both systems; (2) the matrix element squared of the P+ wave with JPC = 1−+ for the η′π− system significantly exceeds that for the ηπ− system, which could testify to the dominance of systems with a valence gluon (qq̄g) in the JPC = 1−+ wave formation; (3) the ratio R = Br(a2−→η′π−)/BR(a−2→ηπ−) = (4.7±1.0(stat.) ±0.4(syst.)) × 10−2 has been obtained.

The reaction pi-p --> eta'eta'n has been studied at p(pi-) = 37 GeV/c. Total of 14 events of this reaction have been selected. It has been shown that in the effective mass spectrum of the eta'eta' system the events are concentrated mainly near the reaction threshold, which might be caused by the decay X(1910) --> eta'eta'. The reaction cross-section has been evaluated: sigma (pi-p --> eta'eta'n) = 110 +/- 40 nb.

The reaction π−p→η′η′n has been studied atpπ=37 GeV/c. Total of 14 events of this reaction have been selected. It has been shown that in the effective mass spectrum of the η′η′ system the events are concentrated mainly near the reaction threshold, which might be caused by the decayX(1910)→η′η′. The reaction cross-section has been evaluated: σ(π−p→η′η′n)=110±40 nb.