# Gell mann and feynman relationship quizzes

H. Kleinert: Collaborating with Feynman at Caltech I was invited by Murray Gell -Mann after he had heard a lecture and various current algebra relations]. Feynman was one of the great figures of twentieth century physics, with a and some important professional and personal relationships went off the rails when that happened. She links to an interview with Gell-Mann, which includes: . The paper “High-energy tests of Lorentz invariance” in my view is a. Hard as he tried, Murray Gell-Mann could never make himself into a legend like his rakish colleague and collaborator, Richard Feynman.

When we were very friendly, we argued. And then later, when I was less enthusiastic about him, we argued also. At one point he was doing some pretty good work—not terribly deep, but it was very important—on the structure of protons and neutrons. We constructed the right theory, called Quantum Chromodynamics, which I named.

He had some other cuckoo scheme based on his partons. Finally after a couple of years he gave up because he was very bright and realized after a while that we were correct.

Feynman often told students to disregard what others had done, to work things out for oneself. Not everyone thought that was good advice. One who disagreed was Sidney Coleman, a Caltech grad student in the late 50s and early 60s.

There was always an element of showboating in his character. He was like the guy that climbs Mt. Blanc barefoot just to show it could be done. And the other way, in fact, was not as good as the first way, but it showed he was different. Those other guys are not all a collection of yo-yos. Sometimes it would be better to take the recent machinery they have built and not try to rebuild it, like reinventing the wheel.

He really could climb Mont Blanc barefoot. A peculiar aspect of the Caltech scientific symposium was that the two talks on particle physics by David Gross and Hirosi Ooguri spent a great deal of time promoting something that Feynman detested. Now I know that other old men have been very foolish in saying things like this, and, therefore, I would be very foolish to say this is nonsense.

I am going to be very foolish, because I do feel strongly that this is nonsense! So perhaps I could entertain future historians by saying I think all this superstring stuff is crazy and is in the wrong direction. I met him first in when spending a sabbatical winter semester at Caltech.

The theory department met every Wednesday for a luncheon seminar where everyone had a chance of presenting his problems and solutions.

At that time, experimentalists had discovered point-like constituents in hadrons with the help of deep inelastic scattering of electrons. The point-like structure had been explained phenomenologically by Feynman with his parton model. Gell-Mann was trying to go further by constructing a fundamental quantum field theory which would combine the point-like structure with well-known results of his Current Algebra. So he gave partons the quantum numbers of quarks and described them by fundamental fermion fields.

Together with Harald Fritzsch he had just shown that currents constructed from free quark fields would explain most of the data. What was missing at that time was an explanation why free fields worked so well although nobody was able to detect quarks as particles in the laboratory!

The model had, however, an important weakness, as was immediately noticed by Feynman: It did not account for the fact that high-energy collisions produced jets of particles the free-quark model would lead to uniform distributions.

It was Gell-Mann who realized that local color gauge fields could provide them with the necessary glue to keep them forever inside the hadrons.

**Richard Feynman, Murray Gell-Mann, Juval Ne'eman: Strangeness Minus Three (BBC Horizon 1964) I**

The point-like structure was assured by what is called that quarks inside hadrons would behave almost like free particles. This property had just been discovered independently by 't HooftPolitzer, and by Gross and Wilczek. Unfortunately, I did not participate in this fundamental endeavor since I was working on a field-theoretic derivation of which had been postulated seven years earlier on phenomenological grounds by Cabibbo, Horwitz, and Ne'emann [Phys.

I found a derivation by generalizing Current Algebra to an algebra of bilocal quark charges of free quark fields. In fact, Yuval Ne'eman [who had discovered insimultanously with Gell-Mann, the fact that mesons and nucleons occur in multiplets representing the symmetry group SU 3 and who became later Israel's Minister of Science and development and of Energy ] was my office mate at Caltech in and was very happy about my derivation.

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We became close friends, and whenever he appeared on a ministerial visit in Berlin, he always found some spare time to meet me and discuss physics protected by several body guards sitting at the tables around us. Gell-Mann, however, convinced me that according to my derivation, the algebra was not exact but only approximately true due to logarithmic corrections. This made it uninteresting to him.

This was quite different with Feynman who loved simple models which can explain things approximately. Feynman appeared regularly at the seminars, and it was an experience to witness the pointed discussions evolving between him and Gell-Mann.

There was always a tension between them, a certain rivalry, which led to interesting exchanges. Some of them were plainly silly: Feynman responded with a boyish smile: Upon which Gell-Mann said "You mean that phenomenological model which I superceded with my quark field theory? The students thoroughly enjoyed seeing the greatest physicists of that time fighting like kids.

In this environment I had the opportunity of participating in a series of seminars Feynman gave to graduate students and postdocs on path integrals with applications to quantum electrodynamics. He told us that when he had first come to Caltech as a young professor he had used path integrals quite extensively in his course on quantum mechanics. Feynman knew that I had developed the group theory of the hydrogen atom in my Ph.

Thesis, so he challenged me to try my luck with the path integral.

- Feynman at 100

We tried a number of things on the blackboard which, however, did not lead to anything. When I returned home to Berlin in spring the problem stuck in my head while I was working out my [in which I calculated the mass differences between current and constituent quarks and various current algebra relations].

### Homepage of Hagen Kleinert

The hydrogen atom sufaced again in when a Turkish postdoc, H. Duru, came to me as a Humboldt fellow. He was familiar with my thesis, so I told him Feynman's challenge, and we began searching for the solution. It turned out that Feynman's definition of path integrals as a product of a large but finite number of ordinary integrals was in principle unable to describe the hydrogen atom.

The situation is similar to ordinary integrals: This success encouraged me to loose my shyness when meeting Feynman again on another sabbatical which I spent mostly in Santa Barbara in I frequently drove to Pasadena, and met with him to discuss physics, and he always had time for me.

We talked for a few hours and usually went to a diner to have a soup together. He was sometimes very funny.

Once he said conspiratively to me: I shall show you a secret, but only if you promise to tell it to everybody.