Nuclear Science and Techniques ›› 2016, Vol. 27 ›› Issue (5):
• NUCLEAR PHYSICS AND INTERDISCIPLINARY RESEARCH •
Shu-Yang Wang, Zhong-Lai Zhu, Zhong-Ming Niu
This work was partly supported by the National Natural Science Foundation of China (No. 11205004) and the Key Research Foundation of Education Ministry of Anhui Province of China (No. KJ2016A026).
Nuclear single-proton resonances are sensitive to the Coulomb field, while the exchange term of Coulomb field is usually neglected due to its nonlocality. By combining the complex scaling method with the relativistic mean-field model, the influence of the Coulomb exchange term on the single-proton resonances is investigated by taking Sn isotopes and N ¼82 isotones as examples. It is found that the Coulomb exchange term reduces the singleproton resonance energy within the range of 0.4–0.6 MeV and leads to similar isotopic and isotonic trends of the resonance energy as those without the Coulomb exchange term. Moreover, the single-proton resonance width is also reduced by the Coulomb exchange term, whose influence generally decreases with the increasing neutron number and increases with the increasing proton number. However, the influence of the Coulomb exchange term cannot change the trend of the resonance width with respect to the neutron number and proton number. Furthermore, the influence of the Coulomb exchange term on the resonance width is investigated for the doubly magic nuclei 40Ca, 56;78Ni, 100;132Sn, and 208Pb. It is found that the Coulomb exchange term reduces the proton resonance width within 0.2 MeV, whose magnitude depends on the specific nucleus and the quantum numbers of resonant states.
Complex scaling method,
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