A kinematical selection of glueball candidates in central production

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Evidence for a 1.9 GeV meson decaying into ηη′

Evidence for a new meson decaying into ηη′ has been found in 38 GeV π-p charge-exchange interactions. The mass and the width of this meson are (1917 ± 15) MeV and (90-50+35) MeV, respectively. Possible spin and parity assignments are JPC = 0++, 1-+ or 2++, isospin and G-parity are IG = 0+. The t-dependence of the differential cross section follows an exponential behaviour exp(bt with a small slope: b = (2±1) (GeV/c)-2.Upper limits on its decay into ππ, ηη and KK exotic interpretation of this meson. © 1989.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Study of ωω systems produced in 38 GeV/c π- p collisions

The π- p→ωωn reaction has studied for the first time at the 70 GeV IHEP accelerator. The six photons from the decay of the two ω mesons were detected in GAMS-2000, a hodoscope multi-photon spectometer. Two resonances decaying into ωω,X (1640) and X(1960), have been observed. Their quantum numbers are JPC=2++, IG=0+. The reaction is dominated by the one-pion exchange mechanism. The production cross sections σ. BR(X→ωω) are 0.65±0.15 μb and 1.0±0.2 μb, respectively. © 1989.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

A hodoscope calorimeter for high enegy hadrons: ihep-iisn-lapp collaboration.

A total absorption hodoscope calorimeter is described. It allows the simultaneous measurement of the energy of the incident hadrons as well as their coordinates with a precision of 1 cm for hadron energies of tens of GeV and higher. The behavior of the calorimeter is studied with incident pions, kaons, antiprotons and electrons.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Studies of the reaction π-p→η′π0n at 38 and 100 GeV/c

The production of η′π0 system in π-p charge-exchange interactions at π- momenta 38 GeV/c and 100 GeV/c has been studied. The 2γ and ηπ0π0 decay modes of η′ leading to 4γ and 8γ final states respectively have been detected. No statistically significant peak is observed in the η′π0 mass spectrum in the range of 1.2 GeV÷2.1 GeV. An upper limit of 6·10-3 has been established for the a20(1320)→η′π0 branching ratio. © 1992 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

G(1590), a scalar meson decaying into two eta-mesons

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Production mechanism of the X(1740) meson

New data from π-p charge-exchange at 38 GeV/c confirm the existence of the narrow X (1740) meson, observed in its ηη decay mode. The upper limit on its width is 80 MeV. It is not observed decaying into either η′η, or π0π0. This meson is produced in charge-exchange by a mechanism other than OPE with a nucleon isobar (probably Δ(1232)), and not with a neutron.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Particle identification with a combined hodoscope calorimeter

The differences in width and in deposited energy between electromagnetic and hadron showers developed by 18.5 and 38 GeV/c pions and electrons in a combined hodoscope detector composed of a GAMS-type electromagnetic calorimeter and a modular hadron calorimeter allow to reject pions or electrons to a level ≪ 0.1% keeping a detection efficiency larger than 90% when the other particle is selected. The hadron calorimeter helps to efficiently reject background in studies of multiphoton decays of neutral mesons with GAMS. © 1989.SCOPUS: le.jinfo:eu-repo/semantics/publishe

Further study of mesons which decay into ωω

The π-p→ωωn reaction has been further studied at 38 GeV/c with increased statistics. The peak at 2 GeV that has been previously observed in the ωω mass spectrum is due to two resonances. The first one is a tensor meson with a mass of 1920 MeV. The second is f4(2050). The branching ratio BR [f4(2050)→ωω] = 0.26±0.06 has been measured. © 1990.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation of a spin-6 neutral meson r(2510)

In a high-statistics experiment (200 events/nanobarn) performed at the 70 GeV IHEP accelerator, a new dipion resonance has been observed in π-p collisions at 38 GeV/c momentum. The gamma-rays in reaction π-p → M0n, M0 → π0π0 → 4γ have been detected in the hodoscope spectrometer GAMS-2000. The new meson, r(2510), has a mass (2510±30) MeV/c2, a width (240±60) MeV/c2 and spin-parity J PC=6++. The production cross-section of the f, h and r mesons decreases exponentially with spin like exp [-0.9 J]. © 1984 Società Italiana di Fisica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe