标题： 介子模式在核表面的处理用于输运描述 显示英文标题

标题： Treatment of Pionic Modes at the Nuclear Surface for Transport Descriptions

摘要： 色散关系和集体介子模式的振幅是在π介子+核子空穴+Δ空穴模型中推导出来的，用于传输描述，通过局部密度近似方法。讨论了介子模式在穿透核表面时如何转化为真实粒子，以及如何改进早期的处理方法。当表面静止时，只有自由介子出现。也讨论了时间依赖的情况，以及当核密度消失时，非物理（即未扰动的Δ空穴）模式如何转化为真实粒子。使用简化的二维情景来研究介子模式在核表面的反射和透射。发现介子模式的反射可能性较小，但可以通过使用近似的局部透射系数将其纳入传输描述中。 显示英文摘要

摘要： Dispersion relations and amplitudes of collective pionic modes are derived in a pi + nucleon-hole + delta-hole model for use in transport descriptions by means of a local density approximation. It is discussed how pionic modes can be converted to real particles when penetrating the nuclear surface and how earlier treatments can be improved. When the surface is stationary only free pions emerge. The time-dependent situation is also addressed, as is the conversion of non-physical (i.e. unperturbed delta-hole) modes to real particles when the nuclear density vanishes. A simplified one-dimensional scenario is used to investigate the reflection and transmission of pionic modes at the nuclear surface. It is found that reflection of pionic modes is rather unlikely, but the process can be incorporated into transport descriptions by the use of approximate local transmission coefficients.