BRAINTREE, Mass. (AP) — A 53-year-old Massachusetts hospital worker stepped forward Thursday to claim the biggest undivided lottery jackpot in U.S. history — a $758.7 million Powerball prize — after breaking the news to her employer the way the rest of us only dream of: “I called and told them I will not be coming back.” “The first thing I want to do is just sit back and relax,” Mavis L.