CROSS SECTION ASYMMETRY OF THE 12C(γ,p0)11B AND 12C(γ,p1)11B REACTIONS AT PHOTON ENERGIES 40...55MeV

The asymmetry of the cross section of the 12C(γ,p0)11B and 12C(γ,p1)11B reactions has been measured in the energy range 40...55MeV using linearly polarized tagged photons of the MAX-lab facility. The asymmetry of the process 12C(⃗γ,p0)11B is Σ ≈ 0.85, that implies one-particle reaction mechanism. The asymmetry of the reaction 12C(⃗γ,p1)11B is smaller, Σ ≈ 0.6...0.7, that may be due to the stronger relative contribution of the 2h−1p mechanism to the dominant one-particle reaction mechanism.

PRELIMINARY RESULTS OF T AND F ASYMMETRIES FOR η PHOTOPRODUCTION FROM THE PROTON

We present preliminary data for the T and F asymmetries in η photoproduction from the proton, along with comparisons to theoretical predictions. The data used in the present analysis were taken using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab, a cryogenic target which utilized transversely polarized protons in a butanol target, and incident tagged photons with energy between 0.62 and 2.93 GeV.

PRELIMINARY RESULTS ON η′ PHOTOPRODUCTION AT GRAAL

The γp → η′p reaction was studied near the threshold, in the 1.44 GeV > Eγ < 1.55 GeV energy range with the tagged photons of the former GRAAL experiment. The two neutral decays γγ(Γi/Γ = 2.10 ± 0.12%) and π0π0η(Γi/Γ = 20.7 ± 1.2%) were analized and preliminary results of the beam asymmetry were extracted together with the invariant masses.