With a weak hyperon-hyperon （YY） interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca （DURCA） processes in the framework of the relativistic...With a weak hyperon-hyperon （YY） interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca （DURCA） processes in the framework of the relativistic mean field theory （RMFT） including σ＊ and φ mesons, in comparison with the results calculated with the strong YY interaction and with no （σ＊ ,φ ） mesons included. In neutron star matter, the weak YY interaction supplies the additional repulsive interaction between hyperons while the strong YY interaction supplies the attractive one. With the weak YY interaction, the effective masses of hyperons are larger than those with the strong YY interaction while smaller than those with no （σ＊ ,φ） mesons included. The threshold star masses for the DURCA processes involving nucleons and A are not sensitive to the strength of the YY interaction. The weak YY interaction leads to larger threshold masses for the DURCA process involving [1]1 and [1]0 than the other two cases. The process involving [1]0 can take place in the neutron star only when the weak YY interaction is used. The weak YY interaction is able to bring in the agreement with the observation of the neutron star with larger mass and faster cooling than the strong YY interaction.展开更多
In the framework of the relativistic mean field theory （RMFT）, the relativistic energy losses of the direct Urea processes with hyperons （Y-DURCA ） for reactions A → p ＋ e ＋ υe and ≡^-→ A＋e＋υe are studied...In the framework of the relativistic mean field theory （RMFT）, the relativistic energy losses of the direct Urea processes with hyperons （Y-DURCA ） for reactions A → p ＋ e ＋ υe and ≡^-→ A＋e＋υe are studied in neutron stars. We calculate the energy gap of A hyperons and investigate the effects of the ^1S0 superfluidity （SF） of A hyperons on the Y-DURCA processes. The calculated results are in line with the recent experimental data △ BAA ～ 1.01 ±0.20-0.11^＋0.18 MeV. The results indicate that the ^1S0 SF of A hyperons exists in most density ranges of happening the two reactions. The theoretical cooling curves are in agreement with observation data.展开更多
The potential energy surfaces are calculated for neutron-deficient At isotopes from A - 190 to 207 in an axially deformed relativistic mean-field approach, using a quadratic constraint scheme for the first time. We fi...The potential energy surfaces are calculated for neutron-deficient At isotopes from A - 190 to 207 in an axially deformed relativistic mean-field approach, using a quadratic constraint scheme for the first time. We find several minima in the potential energy surface for each nucleus, shape-coexistence, and quadratic deform are discussed.展开更多
基金Supported by the Natural Science Fundamental Research Project of Jiangsu Colleges and Universities under Grant No.10KJB140002
文摘With a weak hyperon-hyperon （YY） interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca （DURCA） processes in the framework of the relativistic mean field theory （RMFT） including σ＊ and φ mesons, in comparison with the results calculated with the strong YY interaction and with no （σ＊ ,φ ） mesons included. In neutron star matter, the weak YY interaction supplies the additional repulsive interaction between hyperons while the strong YY interaction supplies the attractive one. With the weak YY interaction, the effective masses of hyperons are larger than those with the strong YY interaction while smaller than those with no （σ＊ ,φ） mesons included. The threshold star masses for the DURCA processes involving nucleons and A are not sensitive to the strength of the YY interaction. The weak YY interaction leads to larger threshold masses for the DURCA process involving [1]1 and [1]0 than the other two cases. The process involving [1]0 can take place in the neutron star only when the weak YY interaction is used. The weak YY interaction is able to bring in the agreement with the observation of the neutron star with larger mass and faster cooling than the strong YY interaction.
基金Supported by National Natural Science Foundation of China under Grant Nos. 10675024, 11075063the National Fundamental Fund project Subsidy Funds of Personnel Training J0730311
文摘In the framework of the relativistic mean field theory （RMFT）, the relativistic energy losses of the direct Urea processes with hyperons （Y-DURCA ） for reactions A → p ＋ e ＋ υe and ≡^-→ A＋e＋υe are studied in neutron stars. We calculate the energy gap of A hyperons and investigate the effects of the ^1S0 superfluidity （SF） of A hyperons on the Y-DURCA processes. The calculated results are in line with the recent experimental data △ BAA ～ 1.01 ±0.20-0.11^＋0.18 MeV. The results indicate that the ^1S0 SF of A hyperons exists in most density ranges of happening the two reactions. The theoretical cooling curves are in agreement with observation data.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10475116, 10535010, and 10235030, and Asia-Europe Link in Nuclear Physics and Astrophysics under Grant No. CN/ASIA-LINK/008 （094-791） and by Major State Basic Research Development Program of China under Grant No. 2007CB815000
文摘The potential energy surfaces are calculated for neutron-deficient At isotopes from A - 190 to 207 in an axially deformed relativistic mean-field approach, using a quadratic constraint scheme for the first time. We find several minima in the potential energy surface for each nucleus, shape-coexistence, and quadratic deform are discussed.
