CHAPEL HILL, N.C.— This seemed like a perfect scenario for Maryland. The Terps were coming off a thrilling win that helped rebuild the shrinking confidence of second-year coach Mark Turgeon’s young team. Until recently, North Carolina had looked like Tar Heels of the past in their powder-blue and white uniforms only. One problem: the Terps didn’t show up for the first half of Saturday’s game at the Dean Smith Center and the Tar Heels looked more like the kind of teams they have usually had dating back to the years when the legend whose name is on the building was still coaching. The result was a 22-point halftime deficit for Maryland that turned into a 62-52 defeat.