Photoproduction of mesons from nuclei - In-medium properties of hadrons

Abstract

Recent experimental results for the in-medium properties of hadrons obtained with photoproduction of mesons from nuclei are discussed. The experiments were done with the TAPS detector at the tagged photon beam of the MAMI accelerator in Mainz. Measured were the final states ${\pi }^{o}X$, $\eta X$, $2{\pi }^{o}X$, and ${\pi }^o{\pi }^{\pm }X$ for ${}^{12}$C, ${}^{40}$Ca, ${}^{93}$Nb, and ${}^{208}$Pb up to the second resonance region. The results were used for an investigation of the in-medium properties of the P${}_{33}$(1232), the P${}_{11}$(1440), the D${}_{13}$(1520), and the S${}_{11}$(1535) resonances. It was found that the cross sections can be spilt into a component which originates from the low density surface region of the nuclei and a component which scales like the nuclear volume. The energy dependence of the surface component is strikingly similar to the deuteron, it shows a clear signal for the second resonance peak. The volume component is lacking this peak and shows an enhancement at intermediate energies. Furthermore the measurement of coherent $\eta$-photoproduction and the final state $p{\pi }^o$ from ${}^3$He is discussed in the context of the search for $\eta$-mesic nuclei.

arXiv commentProceedings of International School of Nuclear Physics, 26th Course, Lepton Scattering and the Structure of Hadrons and Nuclei, Erice-Sicily, Italy 16. - 24. September 2004, to be published in Prog. Part. Nucl. Phys

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Cited by in corpus (10)

• Photoproduction of mesons off nuclei
• Dark sector-photon interactions in proton-beam experiments
• Photoproduction of eta-mesons off nuclei for Eg < 2.2 GeV
• Double pion photoproduction off 40Ca
• Nuclear mass form factors from coherent photoproduction of ${\pi }^0$ mesons
• A new analysis of the MiniBooNE low-energy excess
• Pion emission in 2H, 12C, 27Al, gamma pi+ reactions at threshold
• In-Medium Properties of Hadrons
• Measurement of the beam-helicity asymmetry in photoproduction of ${\pi }^0\eta$ pairs on carbon, aluminum, and lead
• The ratio of $\gamma /{\pi }^0$ production rates in neutrino-nucleus interactions at the $\Delta$ resonance mass region