Sen. John Kerry (D-Mass.) yesterday requested that the Senate Ethics Committee investigate the failure of Republican challenger Jim Rappaport to list his positions in a real estate partnership and a development firm on a financial disclosure report required of Senate candidates. The Globe reported yesterday that Rappaport neglected to list his position as a director of Charles River Park Inc., which developed luxury apartments downtown, as well as his partnership in Commonwealth Reservoir Park Ltd., which owns a 188-unit apartment building on Commonwealth Avenue worth at least $17.2 million. "How much is James Rappaport hiding, and why is he hiding...