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تسجيل مستخدم جديدDynamics of the near threshold eta meson production in proton-proton interaction
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We present the results of measurements of the analysing power for the p(pol)p --> pp eta reaction at the excess energies of Q=10 and 36 MeV, and interpret these results within the framework of the meson exchange models. The determined values of the analysing power at both excess energies are consistent with zero implying that the eta meson is produced predominantly in s-wave.
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We describe a novel technique for comparing total cross sections for the reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta close to threshold. The initial and final state proton-proton interactions are factored out of the total cross sectio
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en evaluated to be mbox{$ sigma = 2.5 pm 0.5~nb$, $~~~ 2.9 pm 1.1~nb$, $~~~ 12.7 pm 3.2~nb$, ~ and $~~~ 25.2 pm 3.6 ~nb $}, respectively. In this region of excess energy the $eta^{prime}$ (958) cross sections are much lower compared to those of the $pi ^0$ and $eta$ production.
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hly as $E_{gamma}$ increases, but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that $phi$-mesons are photo-produced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.
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