8.
.平面直角坐标系\(xOy\)中,双曲线\(C\)\({\,\!}_{1}: \dfrac{{x}^{2}}{{a}^{2}}- \dfrac{{y}^{2}}{{b}^{2}} \)\(=\)\(1(\)\(a > \)\(0\),\(b > \)\(0)\)的渐近线与抛物线\(C\)\({\,\!}_{2}:\)\(x\)\({\,\!}^{2}\)\(=\)\(2\)\(py\)\((\)\(p > \)\(0)\)交于点\(O\),\(A\),\(B\).若\(\triangle \)\(OAB\)的垂心为\(C\)\({\,\!}_{2}\)的焦点,则\(C\)\({\,\!}_{1}\)的离心率为________ .