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تسجيل مستخدم جديدIsospin properties of electric dipole excitations in 48Ca
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Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (alpha,alphagamma) experiment at E_{alpha}=136 MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.
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The nucleus is one of the most multi-faceted many-body systems in the universe. It exhibits a multitude of responses depending on the way one probes it. With increasing technical advancements of beams at the various accelerators and of detection syst
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