Dr. Kevin Campbell was one of a team of Fermi-Lab physicists who accidentally ascertained the Super-Asymmetry paper that was published by Sheldon and Amy. The unexplained differences in their data during an experiment with kaon particles confirmed Sheldon and Amy's work. The data differences were pointed out by a colleague and the Fermi-Lab physicists don't even understand their super-asymmetry work. They are more excited about travelling and appearing on the TV show Ellen. To thank Sheldon, Dr. Campbell jumps up and gives Sheldon a hug that disturbs/vexes both Sheldon and Amy.
Also, Fermi-Lab plans on submitting their two colleagues and Sheldon in their Nobel Prize submission leaving out he neuroscientist Amy.
The doctor returns in "The Laureate Accumulation" trying to fraudulently take credit for Sheldon and Amy's work. He and his colleague Dr. Pemberton appear on Ellen without explaining their work. Also, they show up at Sheldon and Amy's reception and complain about being called imposters (even though in truth, they are).
In "The Plagiarism Schism", Dr. Campbell tells all on the Internet that Dr. Pemberton had plagiarized Barry Kripke's paper and claimed it as his own, thereby destroying Pemberton's chances of winning the nomination and ending his career entirely. This, however, does not affect Dr. Campbell and keeps his career safe instead, which is later followed by his fruitless attempt to bargain with Sheldon and Amy to join them in winning the Nobel Prize.