254) An interesting theoretical paper


Ludwik Kowalski (9/4/05)
Department of Mathematical Sciences
Montclair State University, Upper Montclair, NJ, 07043

As mentioned in another unit, I belong to the International Society of Condense Matter Nuclear Science (ISCMNS). That society has a restricted discussion list, called CMNS, for its members. In unit #249 I wrote about one interesting theoretical interpretation of CMNS phenomena. Here I would like to mention another theoretical interpretation. A link to the following webpage was shared, this afternoon, by one of the contributors.

http://arxiv.org/abs/cond-mat/0505026

It points to an interesting paper, dated Mat 5, 2005, of A. Windom and L. Larsen. I am not a theoretical physicist but I have an urge to share what I think can be understood in terms of elementary nuclear physics concepts. Let me begin by mentioning the familiar form of radioactive decay in which an orbital atomic electron is captured by a nucleus producing a transformation of a proton into a neutron. A well know example of such process is the decay of ⁵¹Cr into ⁵¹V (T=27.8 days). Can a hydrogen ion be transformed into a neutron by capturing an electron? That question is answered positively by Windom and Larsen.

First they remind us that transformation of protons into neutrons has been observed when negative particles captured are negative muons rather electrons. The mass of a muon is sufficiently large to overcome the mass excess of a neutron over a proton. That makes the reaction energetically possible. Transformation of protons into neutrons, by capturing electrons, is energetically impossible; the mass of a free electron is much smaller than the mass difference between neutrons and protons. But it would be energetically possible if the mass of an electron were 2.53 times larger. The authors observe that “the electron mass in condensed matter can be modified by local electromagnetic field fluctuation” on metallic hydride surfaces.

The paper addresses details of this issue in terms of concepts with which I am not familiar. That is why I would very much like to know what quantum electrodynamicists think about the paper of Windom and Larsen. For the time being I will tentatively assume that anticipated mass enhancements of electrons are realistic and that heavy electrons do produce neutrons, occasionally in metals, such as palladium, loaded with hydrogen. The author anticipate that neutrons produced from protons will have very low energies. At those energies capture cross sections are very large. For that reason, they speculate, only a very small fraction of neutrons should be experimentally observable.

One can argue with this. Most neutrons would indeed be absorbed (via nuclear reactions) if they were generated in a thick metallic sheet. But that expectation does not seem to be consistent with the idea that most neutrons are produced at metallic surfaces. The explanation of helium production, via equations (26), makes sense to me but production of ⁶Li, via equations (28), is much less likely. This has to do with the extremely short half-life (2*10^-21 s) of ⁵He. That nucleus will emit a neutron long before it is hit by a second neutrons produced from a proton. And I do not know how to consolidate the suggested mechanism with frequently reported absence of gamma rays. Pd isotopes, for example, absorbing neutrons, would produce several gamma radioactive isotopes of silver. Likewise ¹⁸¹Ta and ⁵⁸Ni would produce gamma radioactive ¹⁸¹W and ⁵⁸Cu, respectively.