中低能区程函近似的复径迹修正及其对核半径的分析

Complex Trajectory Correction to Eikonal Approximation in Low-intermediate Energy and Analyses of Nuclear Radii

分别比较了包含库仑力、库仑力+核力实部及库仑力+核力(实部及虚部)三种情况下的程函近似的径迹修正方法。通过入射能为12.5~50 MeV/u时^(16)O在^(12)C、^(63)Cu和^(208)Pb靶上的弹性散射角分布计算表明了包含核力虚部的复径迹修正方法的重要性。这样的修正方法对于轻靶、中等质量靶上的计算尤为重要。利用复径迹修正下的程函近似重新分析了入射能约为25~65 MeV/u时轻-重核^(6-9,11)Li、^(9-12)Be、^(10-15)B、^(11,12,14-18)C、^(14,16-19)N、及^(15,17,19-21)O在^(nat)Cu靶上的总反应截面数据并得到了相应弹核核物质密度分布的方均根半径。Liatard等利用Glauber模型分析该数据得到的方均根半径结果与Ozawa等利用Glauber模型分析入射能约为650~1 020 MeV/u时高能总相互作用截面数据得到的半径结果间整体性偏差为7.7%,而本文半径分析结果与高能结果间的整体性偏差为1.9%。

Trajectory corrections to the eikonal approximation for the distortions of the projectile trajectory caused by Coulomb potential only,Coulomb+real part of the optical model potential(OMP),and Coulomb+both real and imaginary parts of the OMP,are studied.The necessity of including the imaginary parts of the OMPs in such corrections is demonstrated with the calculations of the elastic scattering angular distributions of ^(16)O on ^(12)C,^(63)Cu and ^(208)Pb targets at incident energies from 12.5 to 50 MeV/u.Complex trajectory correction is found to be especially important for light and intermediate-mass targets.Root mean square(rms)radii of light-heavy nuclei ^(6−9,11)Li,^(9−12)Be,^(10−15)B,^(11,12,14−18)C,^(14,16−19)N,and ^(15,17,19−21)O,were obtained from reanalysis of the total reaction cross sections of these nuclei on a natCu target at 25~65 MeV/u incident energies with the complex trajectory corrections.The overall deviation,between the rms radii obtained by Liatard et al.using Glauber model to analyze this data and the rms radii obtained by Ozawa et al.using Glauber model to analyze the high-energy total interaction cross section data with incident energies of about 650~1020 MeV/u,is 7.7%.The corresponding deviation of the analysis results in this work is 1.9%.