Physics Letters B (May 2015)

Low-energy electric dipole response in 120Sn

  • A.M. Krumbholz,
  • P. von Neumann-Cosel,
  • T. Hashimoto,
  • A. Tamii,
  • T. Adachi,
  • C.A. Bertulani,
  • H. Fujita,
  • Y. Fujita,
  • E. Ganioglu,
  • K. Hatanaka,
  • C. Iwamoto,
  • T. Kawabata,
  • N.T. Khai,
  • A. Krugmann,
  • D. Martin,
  • H. Matsubara,
  • R. Neveling,
  • H. Okamura,
  • H.J. Ong,
  • I. Poltoratska,
  • V.Yu. Ponomarev,
  • A. Richter,
  • H. Sakaguchi,
  • Y. Shimbara,
  • Y. Shimizu,
  • J. Simonis,
  • F.D. Smit,
  • G. Susoy,
  • J.H. Thies,
  • T. Suzuki,
  • M. Yosoi,
  • J. Zenihiro

Journal volume & issue
Vol. 744
pp. 7 – 12

Abstract

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The electric dipole strength distribution in 120Sn has been extracted from proton inelastic scattering experiments at Ep=295 MeV and at forward angles including 0°. It differs from the results of a Sn120(γ,γ′) experiment and peaks at an excitation energy of 8.3 MeV. The total strength corresponds to 2.3(2)% of the energy-weighted sum rule and is more than three times larger than what is observed with the (γ,γ′) reaction. This implies a strong fragmentation of the E1 strength and/or small ground state branching ratios of the excited 1− states. Keywords: Sn120(p,p′), Ep=295 MeV, Relativistic Coulomb excitation, E1 strength below neutron threshold