标题： 在核物质中对$ππ$相互作用的手征约束 显示英文标题

标题： Chirally Constraining the $ππ$ Interaction in Nuclear Matter

摘要： 对于在散射方程中迭代时保持从手征对称性得出的散射长度约束的$\pi \pi$相互作用势的构造，给出了一个通用的方案。该方案仅需要对典型的介子交换模型进行少量修改，因此模型中的耦合常数和截断质量不会受到很大影响。对两种模型在核物质中$s$波$\pi \pi$散射振幅的计算结果与那些违反手征约束的类似模型的计算结果进行了比较。虽然该方案倾向于抑制$\pi \pi$相互作用近阈值强度的积累，但之前提出的满足手征约束的振幅不会表现出向$\pi \pi~s-$波对凝聚不稳定的假设似乎不正确。然而，同时传统的$\pi \pi$相互作用模型如果能很好地拟合散射数据，可以很容易地调整以避免核物质中的不稳定性，而无需借助奇特机制。 显示英文摘要

摘要： A general prescription for the construction of $\pi \pi$ interaction potentials which preserve scattering length constraints from chiral symmetry when iterated in scattering equations is derived. The prescription involves only minor modifications of typical meson-exchange models, so that coupling constants and cut-off masses in the models are not greatly affected. Calculations of $s$-wave $\pi \pi$ scattering amplitudes in nuclear matter for two models are compared with those for similar models which violate the chiral constraint. While the prescription tends to suppress the accumulation of the near sub-threshold strength of the $\pi \pi$ interaction, an earlier conjecture that amplitudes which satisfy chiral constraints will not exhibit an instability towards $\pi \pi~s-$wave pair condensation appears to be incorrect. At the same time, however, conventional $\pi \pi$ interaction models which fit scattering data well can readily be adjusted to avoid the instability in nuclear matter without recourse to exotic mechanisms.