Four teenagers accused of raping a University of Massachusetts student in her Amherst dormitory room in October have pleaded not guilty in Hampshire Superior Court. Justin King, Adam Liccardi, and Emmanuel Bile, all 18 and from Pittsfield, and 17-year-old Caleb Womack of Windsor Locks, Conn., were arraigned Monday on aggravated rape charges. They had pleaded not guilty earlier in district court and were indicted by a grand jury last week. The judge continued the same bail and conditions imposed earlier. All four have posted bail. They are to return to court March 19. None of the defendants is a UMass student.