Question: Kyriakos Tamvakis is a Greek theoretical physicist and professor who has held positions at what European research organization that operates the largest particle physics laboratory in the world?
Sentence (from "Kyriakos Tamvakis"): Kyriakos Tamvakis (Greek: Κυριάκος Ταμβάκης ; born in 1950 ) is a Greek theoretical physicist and professor at the University of Ioannina.
Relevant evidence: Yes