  We prove that the singularities of the $R$-matrix $R(k)$ of the minimal
quantization of the adjoint representation of the Yangian $Y(\mathfrak g)$ of a
finite dimensional simple Lie algebra $\mathfrak g$ are the opposite of the
roots of the monic polynomial $p(k)$ entering in the OPE expansions of quantum
fields of conformal weight $3/2$ of the universal minimal affine $W$-algebra at
level $k$ attached to $\mathfrak g$.
