Let for some real numbers \( \alpha \) and \( \beta \) \( a = \alpha - i\beta \). If the system of equations \( 4i x + (1+i)y = 0 \) and \( 8\left( \cos \frac{2\pi}{3} + i \sin \frac{2\pi}{3} \right)x + \bar{a}y = 0 \) has more than one solution, then \( \frac{\alpha}{\beta} \) is equal to
