The function \( f(x) = x^{3} - 6x^{2} + ax + b \) is such that \( f(2) = f(4) = 0 \). Consider two statements, (\( S1 \)) there exists \( x_{1}, x_{2} \in (2, 4) \), \( x_{1} < x_{2} \), such that \( f'(x_{1}) = -1 \) and \( f'(x_{2}) = 0 \). (\( S2 \)) there exists \( x_{3}, x_{4} \in (2, 4) \), \( x_{3} < x_{4} \), such that \( f \) is decreasing in \( (2, x_{4}) \), increasing in \( (x_{4}, 4) \) and \( 2\, f'(x_{3}) = \sqrt{3}\, f(x_{4}) \).