A recent article in the online science magazine Quanta https://www.quantamagazine.org/20161115-strange-numbers-found-in-particle-collisions/ discusses experimental evidence of a connection between Feynman integrals and periods of motives. Although Quanta usually does a great job with expository articles, in this case so much simplification was necessary for the lay reader that I was left wanting more; a lot more.

Can anyone add more detail to the article, or point me towards another, more in depth exposition?