Which American physicist and winner of the Nobel Prize in Physics in 1955 worked with Robert Retherford to perform the experiment that revealed Lamb shift?
Robert Retherford:  He was a graduate student of Willis Lamb at Columbia Radiation Laboratory. Robert Retherford:  Retherford and Lamb performed the famous experiment revealing Lamb shift in the fine structure of hydrogen, a decisive experimental step toward a new understanding of quantum electrodynamics. Willis Lamb: Willis Eugene Lamb Jr. ( ; July 12, 1913 – May 15, 2008) was an American physicist who won the Nobel Prize in Physics in 1955 "for his discoveries concerning the fine structure of the hydrogen spectrum."
Willis Lamb