fumble into and out of the endzone

Question
if a player fumbles into the end zone and the defense touches the ball before it go's out of the end zone who's ball is it. this is collage

Answer
Richard

The simple answer to your question, it is a touch back and the ball belongs to Team B at the 20 yardline.

A fumble by the offensive team [Team A]into and out of the opponent's endzone is a touchback.  Whether the defensive team "touches" the ball is irrelevant. The fumbled ball is still deemed to be in "Team Possession" of Team A, just not in player possession.  Thus the touching of the ball does not change the possession status of the ball and therefore the ball becomes dead when it goes out of the endzone.  There is one caveat - If the defensive team batted the ball to give it new force or impetus as defined by the rule book, that could change the result of the play - from a touchback to a safety.