Biographical Memoirs Volume 66 (1995) / Chapter Skim
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Henry Primakoff
Henry Primakoff
Pages 266-287
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From page 267... ...
His name is associated with spin waves in ferromagnetism, with the photo-production method for measuring the short lifetimes of neutral mesons, and with an underwater shock wave. He became a leading authority on weak interaction phenomena in nuclei, such as double beta decay, muon capture, and neutrino scattering.
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From page 268... ...
This required escaping across the nearest border, the Prut River, into Romania, trudging for long night hours through woods, and hiding by day in remote farmhouses. Eventually they found a haven on the farm of some relatives about five hours by train from Bucharest.
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From page 269... ...
The interest in philosophy stood Henry in good stead several years later when he interviewed for the Harvard Society of Fellows and was able to heir a lively conversation with the famous philosopher A
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From page 270... ...
founder of the Rochester conferences in high energy physics; and Arthur Kantrowitz, former director of the Avco Everett Research Laboratory. Henry spent his senior year at Columbia taking graduate courses and in one of them, a laboratory course, he met Mildred Cohn, who was to become his wife and a distinguished chemist known for the application of nuclear magnetic resonance to biochemistry.
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From page 271... ...
It was a prophetic choice of topic because Henry came to devote a great deal of effort in the postwar era to weak interactions in nuclei. Possibly the best and most significant paper that Henry wrote was also started while he was a graduate student.
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From page 272... ...
The essential idea of this approach is that, while most of the atomic magnetic moments in the ferromagnet will line up with the external magnetic field, there wait always be a few that, because of temperature agitation, deviate from complete alignment. By means of the boson transformation, Holstein and Primakoff showed that the spin cleviations were not localized on a particular atom, but propagated through the crystal in spin waves.
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From page 273... ...
It is interesting to note that, even though their work played a seminal role in theories of ferromagnetism and anti-ferromagnetism in the 1950s and even though the HolsteinPrimakoff transformation is famous to this day, neither Holstein nor Henry ever worked on this subject again, and as far as ~ can ascertain, they never applied their methods to other problems. Although Henry never worked on the Manhattan Project itself, he did do some research relevant to the Bikini underwater test that led to the discovery of what some authors have called the Primakoff wave.
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From page 274... ...
to reach the vicinity of the Earth. Henry also wrote papers on muon decay, muon capture, and hypernuclei, which were of considerable interest to cosmic ray physicists, the intellectual forerunners of present-day high energy physicists.
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From page 275... ...
Double beta decay is an extremely slow process, being in a certain sense a succession of two ordinary nuclear beta decays, but it is closely tied to important questions regarding the neutrino. If the neutrino has a mass, and if it is its own anti-particle, then it is possible for double beta decay to take place without the emission of neutrinos in the final state; the neutrino emitted in the first ordinary beta decay is reabsorbed in the second.
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From page 276... ...
With the introcluction of the universal V-A interaction for all four-fermion weak interactions in 195S, Henry had realized that the rate for muon capture in nuclei, the second leg in the Puppi triangle, wouIcl be sensitive to the hyperfine splitting of the parent atom. Jeremy Bernstein, T
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From page 277... ...
One motivation for searching for the decay mode without neutrinos is the identity of the neutrino and its anti-particle, or equivalently the question of a conservation law for leptons analogous to that for electric charge. There is considerable empirical evidence for such a law, but the most sensitive test occurs in double beta decay, partly because of the energies available to the exchanged virtual neutrino and partly because of the helicity suppression imposed by the two
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From page 278... ...
We did eventually write a paper about neutrino mass and double beta decay, but we clealt with heavy neutrinos instead of light ones. In 1976 Gell-Mann, Ramond, and Slansky proposed the seesaw mechanism for neutrino masses; they argued that the very light, left-handed neutrinos participating in weak interactions were Majorana particles and should have very heavy, right-handed partners.
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From page 279... ...
Up to now none of these manifestations has been detected, but there is one that does have a chance of being definitively observed in the near future, namely neutrino oscillations. Pontecorvo proposed oscillations as the solution to the solar neutrino problem in 1968 and Henry was excited by the idea almost as soon as he read about it.
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From page 280... ...
REMARKS IN HONOR OF HENRY PRIMAKOFF DECEMBER 18, 1981 AT PHILADELPHIA I have been asked to speak tonight on the topic of "working with Henry." It will be a great pleasure to do so, but I would like to begin by drawing upon the vast reservoir of "Henry stories." Everyone has his own particular favorites, and so here are a few of mine.
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From page 281... ...
Even when his question revealed his previously dormant state, he rarely failed to put the poor speaker on the defensive. Perhaps Henry's greatest tribute to this high art is his definition of insomnia: "When you can't fall asleep in a seminar!
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From page 282... ...
When our first article appeared, in 1959, a reviewer wrote in the English Journal of Physics that he could not understand how two people could write so much about a process that no one had ever seen! Well, rather than be deterred by that remark, we have gone on from slower to even slower processes, and in our latest work we write about one process, proton decay, which would make our original process, double beta decay, seem like a horse race.
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From page 283... ...
W Anderson and Charles Kittel provided me with valuable clues on the early history of the Holstein-Primakoff transformation.
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From page 284... ...
77:205. 1951 Photo production of neutral mesons in nuclear electric fields and the mean life of the neutral meson.
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From page 285... ...
Nuclear double beta decay and a new limit on lepton nonconservation.
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From page 286... ...
Double beta decay and a massive majorana neutrino.
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