U.S. stocks, dollar rise; oil briefly slips below $50

By Hilary Russ NEW YORK (Reuters) - U.S. stocks closed higher on Monday, with the S&P 500 hitting a two-week high on the back of strong earnings and a flurry of deal activity, while the U.S. dollar hovered near a nine-month peak against other world currencies. Merger and acquisition activity spurred Wall Street, headed by Saturday's announcement by telecommunications company AT&T Inc that it plans to buy Time Warner Inc for $85.4 billion in what would be the world's biggest deal this yea