Experiments

The dipole response of proton-rich nuclei Pygmy and Giant Resonances in ³²Ar and ³⁴Ar (S327)

Abstract

We propose to search for proton dipole pygmy resonances in nuclei near the proton drip line. Experimental evidence only exists for neutron pygmy resonances, but calculations infer the occurrence of proton pygmy resonances in proton-rich nuclei in the mass region A = 30 – 50. According to recent RQRPA calculations, low-lying E1 transitions, well below the giant dipole resonance, reveal the dynamics of excess protons oscillating versus the core. The experiment uses Coulomb projectile excitation of secondary 32Ar and 34Ar beams of 700 MeV/u energy from the FRS in-flight separator and the upgraded LAND reaction setup in Cave C. In total, 10 days of beam time are requested.