Particle Physics in a New Universe By Davide Castelvecchi     Stanford University -- A string of recent discoveries in astronomy has left scientists with an unsettling realization: The stuff we know and understand makes up less than 5 percent of the universe. The rest has to be yet-unknown forms of "dark matter" and "dark energy."     At a time of momentous changes in our basic understanding of the universe, a new document outlines the essential role of particle physics in deciphering the laws of nature that govern dark matter, dark energy and more...