- #1
jal
- 549
- 0
What has mainstream decided is the arrangement of the protons and neutrons in the nucleus of the atom?
Lattice or cluster structures or ?
jal
Lattice or cluster structures or ?
jal
We are not really done with studying the nuclear structure, even in terms of effective forces between nucleons. It is however true that we already reached an excellent level of understanding.marlon said:Nothing, the nuclear structure is explained in terms of the interactions between neutrons and protons (coloumb force between protons and residual strong force between protons and neutrons, which holds the nucleus together)
This is disturbing me.jal said:From my understanding, and also from what you have said, what we have figured out is from high energy.
Is there a low energy approach (ground state) low temp.?
Is there any "mapping" coming out of this low energy approach?
Just to be clear, constructing more accurate probes will not eliminate the uncertainty coming from the HUP. It seems that you are suggesting that the accuracy of measurement devices and the inaccuracy due to the HUP are somewhat related. THEY ARE NOT. The HUP has NOTHING to do with devices what so ever and is due to the QM nature of atomic scaled phenomena. Theoretically, we could make devices that determine the exact position of an electron with some momentum p. The point is that if we measure the same electron with same momentum p, the acquired value for the position with be again an exact number. But that number will differ from the previous position value. NOT because of the device but because of the HUP ! You see ?jal said:We do not have any tools that can probe with any accuracy. (uncertainty principle)
Now, I think I understand what you said.What remains to be done is really to understand to role of quarks and gluons in the nuclear medium. For instance, we have a good deal of hints pointing towards the fact that hadrons in the nuclear medium are not the same as free hadrons. The propagate differently. There is color transparency, nuclear shadowing, and many technical details (some of them very minute), but the mere fact that the neutron is stable inside the nucleus is already an excellent indication.
So overall, the picture is still the following (IMHO) : proton and neutrons in the nucleus are vey much alike orange and apples stacked together. Their "quantumness" is tiny enough so that we can apply semiclassical methods and get excellent results. The inherent quantum and extreme-relativistic nature of quarks and gluons inside hadrons however makes it very difficult to go beyond this simple picture, and in fact very little progress has been made since about Heisenberg was working on this problem (ok I am a bit provocative here )
p.158 The parton distributions are determined with much more precision than before.
On the other hand, these analyses also are calling into question, for the first time, the ultimate consistency of the existing theoretical framework with all existing experimental measurements!
(This can be regarded as testimony to the progress made in both theory and experiment – considering the fact that contradictions come with precision, and they are a necessary condition for discovering overlooked shortcomings and/or harbingers of new physics.)
You say "inside the nucleon". Is that because that is the only place that we have reactions that we can input into the formulas?The gluon (or quark) "sea" is the "cloud" of virtual gluons (quarks) and their antiparticles that "exist" inside the nucleon.
Are there ways of producing "a spatial picture" within those constraits?You would have to be careful in transforming this into a spatial picture. Keep in mind that the quantum world is odd, and in a very real way it doesn't make sense to ask "how are the partons distributed inside the nucleon" without specifying how you intend to measure those partons. Different ways of measuring give different results.
Just terminology. The gluon/quark "sea" that is everywhere is typically called the QCD vacuum. When you talk about sea quarks people assume you mean inside some strongly-coupled composite particle.jal said:Hi damgo!
You say "inside the nucleon". Is that because that is the only place that we have reactions that we can input into the formulas?
Would it be speculation or experimental evidence to say that the sea is everywhere?
Sure... there are lots of them, that's the problem. :)Are there ways of producing "a spatial picture" within those constraits?
What about the picture that I found of the proton? Is that one of the quantum possibilities?
You said only, "typically called the QCD vacuum".You say "inside the nucleon". Is that because that is the only place that we have reactions that we can input into the formulas?
Would it be speculation or experimental evidence to say that the sea is everywhere?
damgo said:1) The gluon (or quark) "sea" is the "cloud" of virtual gluons (quarks) and their antiparticles that "exist" inside the nucleon. You can think of them as a sea of particles constantly popping in and out of existence, if you want. Often when you scatter a probe particle off of a nucleon, it doesn't hit one of the physical quarks "making up" the nucleon -- these are called the valence quarks -- but instead one of these temporary quarks or gluons.
Google for the Casimir Effect and read the link i posted above on dynamical quarks.jal said:You said only, "typically called the QCD vacuum".
Have you got an experiment that can be discussed?
jal
What do you mean ? The Casimir effect has nothing to do with an atomic nucleus what so ever since it is a vacuum effect.jal said:I was hoping you would produce something more relevant which would be outside the drip-line (nucleons).
jal said:I'm very well aware of it.
http://en.wikipedia.org/wiki/Casimir_effect
What's the experimental relationship with the "quark sea" which is at less than 0.1 fm?
jal
Sure. There's a bit of a difficulty in talking about direct experiments involving the vacuum, of course, because it's the vacuum... it's not like we can turn it on and off to see what changes! But we can calculate its expected effects from some theory and look for those. jal mentioned the Casimir effect, although I don't know that the QCD contribution has been seen there. Interactions with the QCD vacuum are what cause the "running" of the strong coupling constants -- that is, the strong interactions becomes weaker as you increase the energy of your experiment. This has been observed experimentally, and matches theoretical predictions of the effect of the vacuum.jal said:damgo!
I do not like to argue about faith and opinions.
Do you have some other facts to present that we can discuss.
You said only, "typically called the QCD vacuum".
Have you got an experiment that can be discussed?
jal
jal said:The dynamics of quarks which are bound inside the neucleus has nothing to do with casmir effects.
Hey, all i asked for was a clarification of your question. When did i ever "cherry pick and reject" ANYTHING ?You cannot cherry pick and reject tools just because you want the tool to be the universe.
A nuclear structure refers to the arrangement of particles and forces within an atomic nucleus. This includes the number of protons and neutrons, as well as their organization and interactions.
Nuclear structures are studied through various techniques such as nuclear spectroscopy, nuclear scattering, and nuclear reactions. These methods allow scientists to gather information about the properties and behavior of nuclear particles.
Understanding nuclear structures is crucial for many areas of science, including nuclear physics, astrophysics, and nuclear medicine. It helps us understand the fundamental building blocks of matter and the processes that occur within the nucleus.
Current research topics in nuclear structure exploration include investigating the properties of exotic nuclei, studying the structure of neutron stars, and exploring the potential for controlled nuclear fusion energy.
Nuclear structure research has various potential applications, such as developing new medical treatments, improving nuclear energy technologies, and gaining a deeper understanding of the universe and its origins.