Pinning Down a Proton: Researchers Develop Method to Describe Binding of Protons and Neutrons

April 14, 2010

( -- A researcher at North Carolina State University has helped to develop a new method for describing the binding of protons and neutrons within nuclei. This method may improve scientists' ability to predict and understand astrophysical reactions within stars.

When protons and bind, the process releases energy. This fusion energy is how stars burn. If scientists can determine where these are, what they are doing, and how they are binding, they will then be able to more accurately predict and understand the life cycles of stars.

NC State physicist Dr. Dean Lee and German colleagues Evgeny Epelbaum, Hermann Krebs, and Ulf-G. Meissner, set out to see if there was a more straightfoward approach to describing particle interactions than currently used.

Their results were published in the April 9 issue of .

"These particles can literally be anywhere," Lee says, "so pinning them down is hard. However, we do know that there are hierarchies of attractions between particles and we were able to use these hierarchies to give us a framework for describing how the protons and neutrons could bind with one another. That hierarchy is known as effective field theory."

Lee and his colleagues used a numerical lattice which took into account all of the possible positions of the particles within the nucleus and the corresponding interaction energies. They ran a supercomputer simulation for the elements helium-4, lithium-6 and carbon-12, and demonstrated that the results of those simulations were accurate.

"Currently the indications are that our effective field theory calculations should let us describe nuclei with 16 or fewer and neutrons," Lee says. "But our ability to describe larger using this approach also looks promising."

Explore further: MIT physicist to describe strange world of quarks, gluons

More information: "Lattice effective field theory calculations for A = 3,4,6,12 nuclei" Authors: Dean Lee, NC State University; Evgeny Epelbaum, Hermann Krebs, Ulf-G. Meissner, Forschungszentrum Juelich and University of Bonn, et al. Published: April 9, 2010, in Physical Review Letters.

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not rated yet Apr 14, 2010
Not a whole lot to go on.. but, logic dictates that any particle with no electromagnetic charge has an atrraction to any particle that has either charge, which by logical extrtapolation would be the "force" that holds an atom together. Mind you, I'm probably rehashing an old premise on which the current description (read model) is based, and it might be too obvious or uninteresting.

If the problem is considered to be deeper than that, then I would suggest that we are looking for an answer that may not exist, like "what confers mass on a matter particle", or, "is there a particle for gravity", etc.
not rated yet Apr 14, 2010
Not a whole lot to go on.. but, logic dictates that any particle with no electromagnetic charge has an atrraction to any particle that has either charge, which by logical extrtapolation would be the "force" that holds an atom together.

Since the neutron is a neutral particle without any electromagnetic charge, and the proton has a charge of +1, its pretty obvious that em forces are not at play. Further, simple calculations of the repulsive emf between 2 protons inside a nucleus makes it obvious that the forces that hold them bound must be much stronger than emf.

Thats why we know about the strong nuclear force.
1 / 5 (1) Apr 14, 2010
There is another way to look at the so called strong force. Since like charges repel, a proton should be repelled by its own electromagnetic field. If that is the case simply place a neutron between two protons and the positive field surrounding the three particles should hold this nucleus together. The preceding nucleus would be helium 3. Helium 4 would have two neutrons separating the two protons. This is all explained on pages 31 to 34 at this link:
5 / 5 (2) Apr 15, 2010
Parsec- An un-ionized water molecule is a "neutral particle" but electromagnetic forces are the predominant forces governing the behaviour of water. In short, "neutral" does not mean absence of "charge". There are distributional considerations.
not rated yet Apr 15, 2010
The Strong force could also be Casimir force.
not rated yet Apr 16, 2010
Maybe a torroidal proton is positive only on its top. Then a neutron has that positive charge plugged by an electron and turned upside down. The two nucleons, sticky at the rims, could then rotate against each other forever. Several protons and neutrons rim to rim could form a shell. Several shells one above the other. Protons on the same axis are the same way up and therefore do not repel each other. No need for a strong force, just be very careful about the orientation of each nucleon.
I am not a physicist. Thats just my idea.
not rated yet Apr 17, 2010
I totally agree with Jimster that neutral doesn't mean absence of charge. After all, the neutron has a magnetic moment!

The em force could bind the nucleons together, if the em fields created by the particles have special structure/topology applied to them. An example of this is described in this alternative model:


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