*** SCROLL DOWN FOR VIDEO *** (AP) BERKELEY, Calif. -- California tailback Jahvid Best was carted off the field Saturday night and taken to the emergency room after he landed on the back of his head when he leapt more than 5 feet in the air and flipped over a defender to score a touchdown. Cal spokesman Herb Benenson said that a preliminary evaluation showed Best sustained a concussion, but more tests were being done before a final diagnosis would be announced by the school.