Coefficient of restitution

As shown in the figure, a ball is thrown from point $A,$ making an angle of $60^\circ$ with line $OAS,$ where $OA = \frac{R}{\sqrt{3}}$ and $O$ is the center of the spherical surface of $PQS.$ After striking the hemispherical surface, if the ball rebounds in the direction parallel to $OA,$ the coefficient of restitution between the ball and the surface is $\text{\_\_\_\_\_\_\_\_\_\_}.$

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Note: Neglect the effect of gravity and any type of frictional force.