Spin-flip M1 strengths in Pb

PbのスピンフリップM1遷移

静間 俊行; 早川 岳人; 大垣 英明*; 豊川 弘之*; 小松原 哲郎*; 菊澤 信宏 ; 民井 淳*; 中田 仁*

Shizuma, Toshiyuki; Hayakawa, Takehito; Ogaki, Hideaki*; Toyokawa, Hiroyuki*; Komatsubara, Tetsuro*; Kikuzawa, Nobuhiro; Tamii, Atsushi*; Nakada, Hitoshi*

レーザー逆コンプトン線を用いて、PbのスピンフリップM1遷移強度を測定した。その結果、励起エネルギー7.1MeVから7.4MeVにおいて、M1遷移を観測し、その微細構造を明らかにした。また、RPA(Random Phase Approximation)模型を用いた理論計算を行い、テンソル力の重要性を明らかにした。

Spin-flip strength in Pb has been measured in photon scattering experiments with a quasi-monochromatic, linearly polarized photon beam. The data resolve an giant resonance into at least seven, possibly eight, discrete transitions at energies between 7.1 and 7.4 MeV below the neutron separation energy. The measured strength in this region is found to be larger than the previous report. By comparing the data with a self-consistent RPA estimation using a semi-realistic interaction, a role of the tensor force is reconfirmed.