Which is the paper mentioned in the article?
http://arxiv.org/find/all/1/all:+Punzi/0/1/0/all/0/1
http://arxiv.org/find/all/1/all:+AND+punzi+lett/0/1/0/all/0/...
http://arxiv.org/find/all/1/all:+Punzi/0/1/0/all/0/1
http://arxiv.org/find/all/1/all:+AND+punzi+lett/0/1/0/all/0/...
Links in the text are always a bit cryptic, it would help if they were to put an info box at the end of articles with all the relevant links — but I don't want to complain, putting the link in there at all is already a pretty masssive improvement.