We investigate the role of the effective range on the bulk viscosity of $s$- and $p$-wave Fermi gases. At resonance, the presence of the effective range breaks the scale invariance of the system, and hence results in a non-zero bulk viscosity. However, we show that the effective range plays a very different role in the two cases. In the $s$-wave case, the role of the effective range is perturbative, and its contribution to the bulk viscosity vanishes in the limit of zero effective range. On the other hand, the effective range in $p$-wave Fermi gases leads to a non-zero bulk viscosity, even in the zero-range limit. We employ a general diagrammatic approach to compute the bulk viscosity spectral function that includes the effects of the effective range. We then compute the analytic expressions for the spectral function in the high temperature limit, at low- and high-frequencies. We also derive the sum rules for the bulk viscosity spectral function for both $s$- and $p$-wave gases.

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有效范围在共振和波波费米气体的体粘度中的作用

我们研究了有效范围对胶粘剂本体粘度的作用 $s$-和 $p$费米气体。在共振时，有效范围的存在破坏了系统的水垢不变性，因此导致了非零的体积粘度。但是，我们表明，在两种情况下，有效范围起着非常不同的作用。在里面$s$波动情况下，有效范围的作用是微扰的，其对体积粘度的贡献在零有效范围的极限内消失。另一方面，有效范围$p$波费米气体即使在零范围极限内也导致体积粘度不为零。我们采用一般的图解方法来计算包括有效范围影响在内的本体粘度谱函数。然后，我们在高温和低频下计算光谱函数的解析表达式。我们还推导了两种方法的体积粘度谱函数的求和规则$s$-和 $p$波气体。