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Discovered the positron? Umm... what?

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I thought that Carl Anderson discovered the positron. At least, that's what the Nobel Prize committee said when they awarded him the Nobel Prize in 1936 for discovering the positron. If you want to claim that it was really not Anderson, but Chung-yao Chao, I think some explanation is in order. -- Reuben 03:28, 4 Feb 2005 (UTC)

OK, I've now read the papers involved, and I can't see that this claim is well-founded. Removing it. If anybody wants to restore the claim that Chao discovered the positron, please substantiate, preferably with a journal citation. -- Reuben 08:00, 4 Feb 2005 (UTC)


Hello, dear Reuben. About the article Chung-Yao Chao, He was the first scientist that captured the positive-charged electron (positron) through what was later confirmed as the ‘electron-positron annihilation’, although he was not given the Nobel Prize (The prize was later given to his classmate Carl D. Anderson). (reference 1, "C.Y.ChaoPair Creation and Pair Annihilation",International Journal of Modern Physics A ,vol.17 1989. 2, Chinese Science and the `Nobel Prize Complex' , Cong Cao). Does it mean that he tested the existence of antimatter? Maybe the description The discoverer of antimatter, and the first scientist that observed positron is not the exact. My major is not physics. Gosta Ekspong, the former Chairman of the Nobel Committee for Physics of the Royal Swedish Academy of Sciences, also had comment on this matter. Wikinu 06:50, 20 Feb 2005 (UTC)

Hi Wikinu, thanks for the citation. I'll be able to look it up in a couple of weeks. The relevant articles I've found are these (web versions require a subscription).
  • Chao, C. Y. "Scattering of Hard gamma-Rays," Phys. Rev. 36, 1519–1522 (1930)
  • Anderson, Carl D. "The Positive Electron," Phys. Rev. 43, 491–494 (1933)
The first is a paper by Chao from 1930, and the second is Anderson's paper announcing the discovery of the positron (1933). Anderson's paper cites Chao's as one of its references. I don't have access right now to the 1989 paper you mentioned, but the abstract is as follows:
"C. Y. Chao's contribution to physicists' acceptance of QED in 1933–1934 through his experiments of 1930 is analyzed. It is pointed out that Blackett and Occhialini's key suggestion of 1933 about hole theory was based on identifying Chao's "additional scattered rays" (1930) as due to pair annihilation."
This seems to refer to the same work by Chao published in the "Scattering of hard gamma-rays" paper from 1930. Chao had measured the scattering of gamma rays by various materials, and compared the results to the predictions of the Klein-Nishina formula (article at MathWorld). For lighter target nuclei, the results agreed with the predictions. For lead, there was more scattering than predicted. Later, after Anderson's discovery of the positron, this additional component of scattering was understood as the result of pair production, in which the gamma ray produces an electron and a positron (anti-electron). However, Chao didn't have any reason to believe that this increased scattering rate had anything to do with positrons. In fact, he suggested several possible explanations, none of which involved antimatter. Reuben 09:32, 20 Feb 2005 (UTC)
I do not know much. So pls edit the article as suggested by fact. I once read news about it. 70 Tsung-Dao Lee: A Chinese scientist should be awarded Nobel Prize 70 years agao. It's said by Tsung-Dao Lee, Nobel prize winner and a student of Chung-Yao Chao. Lee said, Ekspong told him that Ekspong searched the document about Chung-Yao Chao, Swedish Academy of Sciences seriously considered to award Nobel prize to Chao, but a german physicist got defferent result from the experiment...... EkspongEkspong If this is true, it means the discover by Chao is a big achievment. Wikinu 12:41, 23 Feb 2005 (UTC)