In a matter of a few short months, Chad Johnson and Evelyn Lozada went from married couple to kaput. The former Pats receiver and the reality TV star were officially divorced Wednesday — four weeks after Johnson was arrested on a domestic battery charge. The couple was married July 4. Johnson was a member of the Miami Dolphins when Lozada — Antoine Walker’s ex and a cast member of TV’s ‘‘Basketball Wives’’ — accused him of head-butting her during an argument. She immediately filed for divorce, and the Dolphins cut Johnson.