If the ball is not touched by the jumpers before it hits the floor, what must the referee do?

When the ball does not touch either jumper during a jump ball situation and subsequently hits the floor, the correct course of action is to try the jump ball again. This is because the rules governing jump balls stipulate that a valid jump ball must involve the ball being legally touched by the participants. When it simply falls to the ground without any interaction, the procedure is considered incomplete, thus necessitating a re-jump.

Continuing play normally would not apply in this case, as the jump ball situation has not been resolved properly. Resetting the shot clock is also not relevant, since the shot clock operates under different conditions that do not involve a restart due to an invalid jump. Changing possession to the other team would also not be appropriate, as the rules dictate that a repeat of the jump ball is required to settle the possession correctly. Therefore, re-attempting the jump is the established protocol for this scenario.