标题： 超新星物质中的中微子-核子散射来自维里展开 显示英文标题

标题： Neutrino-nucleon scattering in supernova matter from the virial expansion

摘要： 我们将我们的缔合方法推广到研究低密度下核物质的中性流中微子反应。在长波长极限下，缔合展开对中微子-核子散射率以及密度响应 S_V 和自旋响应 S_A 做出了模型无关的预测。我们发现即使在低密度下，S_A 也显著低于 1。我们提供了一个简单的拟合公式 S_A^f(n,T,Y_p)，用来表示轴向响应作为密度 n、温度 T 和质子分数 Y_p 的函数。这个拟合在低密度下重现了我们模型无关的缔合结果，在高密度下则重现了 Burrows 和 Sawyer 随机相位近似 (RPA) 的结果。我们的拟合可以方便地纳入超新星模拟中。初步的一维超新星模拟表明，在核心坍缩超新星吸积阶段的增益区域，轴向响应的降低可能会增强中微子加热率。 显示英文摘要

摘要： We generalize our virial approach to study the neutral current neutrino response of nuclear matter at low densities. In the long-wavelength limit, the virial expansion makes model-independent predictions for neutrino-nucleon scattering rates and the density S_V and spin S_A responses. We find S_A is significantly reduced from one even at low densities. We provide a simple fit S_A^f(n,T,Y_p) of the axial response as a function of density n, temperature T and proton fraction Y_p. This fit reproduces our model independent virial results at low densities and reproduces the Burrows and Sawyer random phase approximation (RPA) results at high densities. Our fit can be incorporated into supernova simulations in a straight forward manner. Preliminary one dimensional supernova simulations suggest that the reduction in the axial response may enhance neutrino heating rates in the gain region during the accretion phase of a core-collapse supernovae.