We study Efimov physics of three identical bosons with pairwise multichannel interactions for Feshbach resonances of adjustable width in magnetic field. We find that the two-body multichannel realization of the interaction can affect the universal Efimov spectrum, especially for resonances of intermediate width. We analyze two scenarios that are equivalent on the two-body level but differ in their realization in three-body multichannel spin space. The deviations in the Efimov spectra of these scenarios are caused by trimer states in the closed interaction channels whose binding energy and coupling strength to the Efimov states depend on the spin realization. However, in the narrow resonance limit the Efimov spectrum is set by the resonance width parameter $r^{*}$ only and does not depend on the realization in spin space. We find this limit to be even independent of the interaction potential considered. In the broad resonance limit all excited Efimov trimer energies approach the ones from the corresponding single-channel system for the scenarios investigated.

中文翻译：

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从宽到窄的Feshbach共振，在Efimov体制中的多通道效应

我们研究具有成对多通道相互作用的三个相同玻色子的Efimov物理学，用于磁场中宽度可调的Feshbach共振。我们发现，相互作用的两体多通道实现会影响通用Efimov谱，特别是对于中等宽度的共振。我们分析了两个场景，它们在两体级别上是等效的，但在三体多通道自旋空间中的实现方式有所不同。这些场景的Efimov光谱中的偏差是由封闭相互作用通道中的三聚态引起的，该三聚态的结合能和与Efimov态的耦合强度取决于自旋实现。但是，在狭窄的共振极限下，Efimov谱由共振宽度参数设置${\mathrm{[R}}^{*}$仅且不依赖于自旋空间的实现。我们发现该限制甚至与所考虑的交互作用潜力无关。在宽泛的共振极限下，对于所研究的场景，所有激发的Efimov三聚体能量都接近相应单通道系统的能量。