content_image/351668.jpg content_image/351677.jpg content_image/351678.jpg
<img src='content_image/351668.jpg'>

of the fermion case: 

At this point c ( − 1 . 3) ≈ 0 . 11. 

<img src='content_image/351677.jpg'>

The ratio η/s is shown in Figure 23. It has a minimum at µ/T = − 1 . 72 near the critical point and in the physical region: 

Recall, the region µ/T > − 1 . 45 is unphysical. 

## IX. MULTIPLE SPECIES OF PARTICLES 

<img src='content_image/351678.jpg'>

Let us suppose the gas consists of multiple species of particles labeled by the index “a”, of mass m$_{a}$ , chemical potential µ$_{a}$ , and statistical parameter s$_{a}$ = ± 1. Introduce 

