Before revision:  The value of p where the player is indifferent between the arms is the Gittins index g  (\mu,\beta) > m, where m is the mean of the risky arm and \beta the discount factor .
After revision:  The value of p where the player is indifferent between the arms is the Gittins index g = g (\mu,\beta) > m, where m is the mean of the risky arm and \beta the discount factor .