Java alphabeta search

Is this code correct?

This code was adapted from this alphabeta pseudocode. AlphaBeta search is often mentioned but getting the code 100% correct is tricky.

IGame is an interface with two methods:
getScore() - evaluates the current game state from the viewpoint of the AI
generateMoves() - creates possible moves from the current game state.

class Search
{
    Move bestMove;

    Move findBestMove(int ply, IGame g)
    {
        bestMove = null;
        alpha_beta(ply, g, Integer.MINIMUM, Integer.MAXIMUM);
        return bestMove;
    }

    int alpha_beta(int depth, IGame g, int alpha, int beta)
    {
        if (depth == 0 || g.isGameFinished()) return g.getScore();

        Move[] gameMove = g.generateMoves();

        for (int i = 0; i < gameMove.length; i++)
        {
            g.execute(gameMove[i]);
            int score = -alpha_beta(depth - 1, -beta, -alpha);
            g.undo(gameMove[i]);

            if (alpha < score)
            {
                alpha = score;
                bestMove = gameMove[i];
            }
            if (beta <= alpha) return alpha;
        }
        return alpha;
    } 
}