None
No description provided.
No description provided.
No description provided.
The reaction π − p→ π 0 ηn ↳2y ↳2y has been analyzed using data of an experimental performed at the 70 GeV accelerator, with the NICE 648 channel hodoscope spectrometer for γ ray detection. Events with 4 γ seen are used for the analysis. A method is applied, which allows the determination of the number of π 0 η events for each mass, cos θ GJ and t bin. Mass spectra, t distributions and decay angular distributions for the π 0 η system are presented. The cross section for the production of A 2 0 is found to be 2.7 ± 1.1 μ b at 40 GeV/ c beam momentum. No indication of a resonant 1 − state in the π 0 η system is observed, in spite of the fact that this state is allowed for the π 0 η system on the same footing as the observed 0 + and 2 + resonances.
ERROR INCLUDES UNCERTAINTIES IN SEVERAL CORRECTIONS AND IN BACKGROUND SUBTRACTION.
π − p , K − p and p p total cross-sections are measured at momenta up to 65GeV/ c with statistical accuracy 0.3 ÷ 0.6% and systematical (scale) error ≈ 0.4%.
No description provided.
No description provided.
No description provided.
An experiment using the Fermilab Single Arm Spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied the reactions a+p→c+X, where a and c were π±, K±, p, or p¯. Extensive measurements were made at 100 and 175 GeV/c beam momenta with the outgoing hadrons detected in the SAS covering a kinematic range 0.12<x<1.0 and pT<1.25 GeV/c. Additional data covering a more restricted range in x were also gathered at 70 GeV/c incident momentum. In this high-statistics experiment, the identification of both the incoming and outgoing charged hadrons were made with a total of eight Čerenkov counters. New and extensive single-particle inclusive data for charged-particle production in low-pT hadronic fragmentation are presented. The average associated charged-particle multiplicity and pseudorapidity distributions are also given.
No description provided.
No description provided.
No description provided.
In a new experiment we have obtained 3006 new events in the reaction π − p → φφ n, approximately doubling the statistics which now total 6658. A refined partial wave analysis of the φφ system again reveals three resonances (g T , g T′ , g T′' ) with I G J PC =0 + 2 ++ . The absence of the OZI suppression, and the observation of only three J PC =2 ++ states (g T , g T′ , g T′' ) which comprise virtually all the cross section are unusual characteristics of the data. The large φφn signal occurs over a mostly structureless and incoherent φK + K − n background. All these unusual characteristics are well explained if these states are produced by 1–3 glueballs (multigluon resonances).
Total cross section plus systematic error supplied by authors.
Absolute cross section based on total cross section of 50 +- 15 nb. Errors quoted in Table are statistical only.
New results on a high statistics measurement of pion-nucleon charge exchange scattering at 40 GeV/ c , extending in momentum transfer up to − t = 1.8 (GeV/ c ) 2 , are reported and compared with an optical impact parameter model, together with previous data for the reaction π − p → ηn at the same energy. The imaginary part of the pole trajectory b 0 ( s ) is determined from the slope of the tangent to the maxima of (−t) 1 2 d σ d t . The linear increase of Im b 0 ( s ) with log s , which has been observed at low energies, continues up to 40 GeV/ c .
AT SMALL -T, THE BINNING TENDS TO SMEAR OUT THE FORWARD DIP.
None
No description provided.
Cross-section data are presented for pion proton charge-exchange scattering in the momentum range 20 to 50 GeV/ c . The experiments were performed at 70 GeV IHEP accelerator.
No description provided.
The invariant mass spectrum of neutral final states produced in π − p charge-exchange scattering at 40 GeV/ c has been studied, searching for heavy particles decaying in 2γ. A peak is observed around 2.85 GeV/ c 2 . The cross section of the reaction π − p→X(2.85)+n, times the branching ratio of the X→2 γ decay, is measured to be σ × BR ⋍ 2 × 10 −34 cm 2 .
MEAN VALUE OF -T = 0.28 +- 0.04 GEV**2.
The invariant mass spectrum of neutral meson states from π − p interactions at 40 GeV/ c incident momentum has been investigated in a high statistics experiment performed at the 70 GeV IHEP accelerator. To detect the high energy photons coming from the produced neutral states, a hodoscope spectrometer with a computer on-line was used. A clear structure on the mass spectrum of dipions produced in the reaction π − p→π°π°n is observed at 2 GeV. The decay angular distributions show in this mass region the variation with mass typical of a state with a spin J = 4. The mass of the observed meson is found to be M = (2020±30)MeV and the estimate of the full width is (180±60) MeV.
No description provided.