Is there an excited state of the proton at 13 GeV ?
My name is John Hagel, I live in London, England, and I found out about the Syracuse ‘Ask a Particle Physicist’ webpage by just plugging in some keywords! I am actually a chemist by training, but, whilst doing research at Caltech in 1976-78, I became interested in particle physics. Whilst at Caltech, I seem to remember an infamous professor of physics by the name of Ricardo Gomez once telling me that the proton had an excited state at somewhere around 13-14 GeV. Is that true, or have I dreamt it? If it does, has a satisfactory explanation for this fact ever been put forward? I can find no reference to it in modern textbooks of particle physics. I look forward to your reply with great interest. Thank you in advance for your time. It is very much appreciated. With kind regards, John Hagel Dear John, I do not know of any excited state of the proton at that mass. There *is* an excited state, called the “Delta” resonances. The Delta resonances have a mass of 1.23 GeV (10 times less than you
