 { (\alpha - \beta |v|^0) v}\cdot \nabla _v \left \{\left [ 0 - \chi \left ( \frac{0|v|}{r_0}\right )  \right ]\varphi \left ( x, r{ \frac{v}{|v|}}\right ) \right \}{ f ^\varepsilon}(t,x,v)\,{ \mathrm{d}(x,v)}\;\mathrm{d}t} \nonumber \\ & = \