Update on the nucleus-massive mesons coupling.

[arivero]

Last december I was asking for the possibility to couple the highest massive bosons to the nucleus. I was aiming for some kind of many body effect to give relevance to the total mass of the nucleus, besides the one of the independent nucleon.

To get this, one expects the contribution of more massive particles to be only a perturbation of the strong coupling induced by pions (and the other lesser massive particles). So I concentrated in the upper side of the spectrum of particles: top mesons, higgs, and W-Z, even if some people told me about researching the rest of particles.

Well, I am surprised because I finally did a plot of the medium range bosons (J/Psi, B, and Upsilon), see it at
http://dftuz.unizar.es/~rivero/research/nucleo/mesones.pdf
and, hmm, it does not contradict the possibility of relating them to total mass. There are two main gaps in the spectrum: one between the J/Psi particles and the bottom mesons B(s)-B(c), another between the bottom mesons and the Upsilon. The gaps happen to be at 5 atomic mass units and 7-8 amu. And no nucleus happens at 5 or 7aAmu, these are the only known atomic numbers where there is not stable nucleus. So the low energy nucleus also could be said to notice the masses of medium mass mesons.

[edited] Honestly, the role of these mesons is unclear. The nuclei 4He, 8B (that disintegrates to two 4He) and 12C hold the highest energies per nucleon in the zone. The mesons could be helping to this, or on the contrary contributing to decrease the energy per nucleon of the extant nuclei. The increased stability of even-even nucleus goes further, until a total of 30 nucleons, where the odd-odd nucleui begin to be stronger.

Yours,

Alejandro
PS: the units of the plot are MeV. Horizontal axis is mass, vertical axis is decay width. In the mass scale, the grid shows multiples of atomic mass. At 0,350 I have plotted nuclei mass for reference.

[EDITED 24 Feb]: the most recent version of the manuscript is not the one at arxiv, but the one in my site,
http://dftuz.unizar.es/~rivero/research/masas.pdf

 

[arivero]

an idea

I have thought of another mechanism. Supposse that a nucleon moving in the nucleus has a mean time between impulses of about the inverse of the mass of the nucleus. Then if this mass equals some very massive boson, the feynmann graphs for self-energy contribution of this particle will interfere with the ladder graphs of interaction nucleon nucleus.

Is the mean time between impulses documented somewhere? If it depends of proton mass and number of particles in the nucleus, then it should be enough, as the product is total mass. But if it depends of nuclear density and orbital number, the calculations seems more involved.

 

[arivero]

For any of you following this mini-saga, updates have been uploaded into
nucl-th/0312003 and a new preprint is at hep-ph/0405076.

(This last one is at the drip line, so one could be tempted to say that the weak bonding approximation is valid there. But note that the momentum exchanged by the neutrons surely is even weaker than the bonding)

 

[arivero]

Final

I have decided to put to sleep for some months the Lamb's Balance effort. Of course, Esau prizes will keep valid and honored until someone claim them.

The final effort has resulted in a trilogy:

• nucl-th/0312003 Standard Model Masses and Models of Nuclei
• hep-ph/0405076 The 115 GeV signal from nuclear physics
• http://dftuz.unizar.es/~rivero/research/LS9530.pdf (EXT-2004-048) The Lamb's Balance

and an http://dftuz.unizar.es/~rivero/research/uno.gif , superposed to M. Uno et al' work.

The analysis seems to confirm that a part of the magicity comes from the electroweak particles -not rare, as one of them already has principal role in decay of nuclei- and it suggests a not-minimal-but-almost extension of the Higgs sector, agreeing with the excess events that happened in the last LEP run. Either that, or LEP events have its origin in some unaccounted use of nuclear data in CERN detectors (then reversing all my arguments, ugh).

Besides the purely theoretical work, it is perhaps possible to do some additional empirical work by studying if beta decay, the W mediated nuclear reaction, depends somehow on atomic mass. Regretly the main dependence of beta decay is on allowedness (angular momentum plus isospin, say) of reactions, and one should do a separate analysis for each subtype of decay.

 

[arivero]

and what about the W?

well, here attached you can see a plot of all the known beta transitions with log ft above and below 5.9. If you look in the "above" histogram, you will notice a first jump around 68 GeV and then another exactly at 80 GeV (86 atomic mass units, of course), which is the mass of the W- particle causing the beta decay.

 

[arivero]

a simpler question

Reviewing my work, a friend has come with the following, supposedly simpler, question, as it does not relate to high energy physics:

"Why the nuclei in the series
N=...20,28,50,(64),82,126,184 at the neutron drip line
have the same atomic number A that the respective nuclei
Z=...20,28,(40),50,(58),82,114 at the proton drip line?"

Is there an answer? Or Is this an open problem on nuclear isospin breaking?
Does it depend on magic numbers? Or is it a general property that the distance from the stability line to neutron and proton driplines is the same?

Alejandro