Sorry, Beatles fans: two sources are throwing cold water on rumors that Paul McCartney has sold the rights to the Beatles back catalog to iTunes.Sony/ATV Music Publishing, the joint venture owned by Sony and singer Michael Jackson, has thrown cold water on newspaper stories out of London that The Beatles catalog would soon be available on iTunes. A spokeswoman for Sony/ATV Music Publishing told CNET News.com that the reports are “untrue.”Sony/ATV is a pretty good source. While EMI Group owns the recording rights