O.C.G.A. § 17-16-21

Prior to arraignment, every person charged with a criminal offense shall be furnished with a copy of the indictment or accusation and, on demand, with a list of the witnesses on whose testimony the charge against such person is founded. Without the consent of the defendant, no witness shall be permitted to testify for the state whose name does not appear on the list of witnesses as furnished to the defendant unless the prosecuting attorney shall state that the evidence sought to be presented is newly discovered evidence which the state was not aware of at the time of its furnishing the defendant with a list of the witnesses.