New picture of atomic nucleus emerges

Mar 02, 2012 By Jared Sagoff
When most of us think of an atom, we think of tiny electrons whizzing around a stationary, dense nucleus composed of protons and neutrons, collectively known as nucleons. A collaboration between Argonne and Jefferson National Laboratories has demonstrated just how different reality is from our simple picture.

(PhysOrg.com) -- When most of us think of an atom, we think of tiny electrons whizzing around a stationary, dense nucleus composed of protons and neutrons, collectively known as nucleons. A collaboration between the U.S. Department of Energy's Argonne and Thomas Jefferson National Laboratories has demonstrated just how different reality is from our simple picture, showing that a quarter of the nucleons in a dense nucleus exceed 25 percent of the speed of light, turning the picture of a static nucleus on its head.

"We normally picture a nucleus as this fixed arrangement of , when in reality there's a lot going on at the subatomic level that we just can't see with a ," said Argonne physicist John Arrington.

Arrington and his colleagues used one of the Jefferson Lab's large magnetic to look at the behavior of nucleons in some light atoms—deuterium, helium, beryllium and carbon. Physicists had long believed that "short-range correlations"—the interactions within nuclei that produced high-momentum nucleons—would largely reflect the density of the atom's nucleus, as they did in heavier nuclei.

This hypothesis largely held true, except in the case of beryllium. Unlike the other atoms under investigation, beryllium contains two clusters of nucleons, each resembling a helium-4 nucleus. These nucleons, in turn, are bound to one additional neutron. Because of this somewhat unwieldy configuration, the nucleons in beryllium experienced a relatively high number of collisions despite being one of the least-dense nuclei.

The nuclear "speed boost" observed by the researchers may have resulted from the interaction between the quarks that compose the nucleons that come into contact with one another. Each proton and neutron consists of three quarks that are bound extremely tightly to one another. When nucleons get too close together, however, the forces that usually constrain quarks can get disrupted, modifying the quark structure of the protons and neutrons or possibly even forming composite particles from the quarks of two nucleons.

"Because the interaction between two closely spaced nucleons is responsible for both changes in momentum and quark behavior, I think it's imperative that scientists continue to study the phenomena that take place there," Arrington said. "Our next measurement will try to examine this question directly by taking a snapshot of the quark distributions at the moment when the nucleons are close together."

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Husky
1.5 / 5 (8) Mar 02, 2012
at some point in the future we can imagine the development of quark fission/fusion for energy purposes, the barriers to overcome such strong interactions make the coulomb barrier pale, but who knows, very high powered attosecond lasers or ultradense magnetic field can rip their fabric appart...
Vendicar_Decarian
3.1 / 5 (12) Mar 02, 2012
Yup. Just like I can imagine forest pixies dancing upside down on purple leaves that are sprouting from the backs of flying space turtles.
Noumenon
4.2 / 5 (10) Mar 02, 2012
at some point in the future we can imagine the development of quark fission/fusion for energy purposes, the barriers to overcome such strong interactions make the coulomb barrier pale, but who knows, very high powered attosecond lasers or ultradense magnetic field can rip their fabric appart...


You can't separate quarks from each other, such is the nature of the strong force. In fact if you tried to "pull" two quarks apart it would require so much energy, you would just end up creating new particles.
Kinedryl
3.7 / 5 (6) Mar 02, 2012
A slightly bit more technical article about this research. Due the presence of free neutron beryllium-9 has a large scattering cross section for high-energy neutrons, during which it undergoes a (n,2n) neutron reaction to 8Be, which then instantaneously breaks into two alpha particles; that is, beryllium is a neutron multiplier, releasing more neutrons than it absorbs.
thermodynamics
4 / 5 (4) Mar 02, 2012
"When most of us think of an atom, we think of tiny electrons whizzing around a stationary, dense nucleus composed of protons and neutrons, collectively known as nucleons."

Has anyone really thought in these terms since their first course in quantum mechanics? High momentum is the result of the uncertainty principle as distances shrink.
Deesky
3.5 / 5 (8) Mar 02, 2012
Has anyone really thought in these terms since their first course in quantum mechanics?

Wow. You really think that many posters on this site have actually attended a course in quantum mechanics?
Turritopsis
3 / 5 (6) Mar 03, 2012
"Has anyone really thought in these terms"

Quantum mechanics is about measuring, not thinking. Influence and measure effect. Quantum theories visualize reality (model). Models are tested through physical (mechanical) experimentation and results are measured (quantized).

Quantum mechanics are always true. 100% certainty.

Theories can only be proven realistic. In other words they approach certainty.

we think of tiny electrons whizzing around a stationary, dense nucleus


Has nothing to do with quantum mechanics, just an outdated (disproven) atomic theory. Atoms are all energy. The inner core of the atom contains positive and negative charges (quarks) the outer shell of the atom contains negative charges (electrons). You cannot ask where an electron is in the atomic shell. The electron is the atomic shell. To see it you must interact with it, but then the electron wave breaks and the electron becomes the point of observance. The observer creates particle by taking measurement
Turritopsis
2 / 5 (8) Mar 03, 2012
Physical measurements destroy the flow of time. Time moves at the speed of light. The observer captures a moment (measures physical dimensions). Particle.

Time measurements destroy physicality. At lightspeed all physical matter is a wave. The wave takes x time to cover distance d. Wave.

Particle wave duality.

Only in the moment is it particular in nature. Outside of the moment you can measure the moments length. Time is the rate of change of the physical. The physical only exists in time.

Particles are the creation of the observer breaking the wave pattern that is energy in time.
TabulaMentis
1 / 5 (3) Mar 05, 2012
Wow. You really think that many posters on this site have actually attended a course in quantum mechanics?
I thought quantum physics was a leg exercise.

From article:
A collaboration between the U.S. Department of Energy's Argonne and Thomas Jefferson National Laboratories has demonstrated just how different reality is from our simple picture, showing that a quarter of the nucleons in a dense nucleus exceed 25 percent of the speed of light, turning the picture of a static nucleus on its head.
I do not understand how they claim the nucleons can travel FTL. Can anyone please explain? If that is true then quarks and electrons may very well be higher-dimensional micro black holes.
CardacianNeverid
3.2 / 5 (9) Mar 05, 2012
From article:
A collaboration between the U.S. Department of Energy's Argonne and Thomas Jefferson National Laboratories has demonstrated just how different reality is from our simple picture, showing that a quarter of the nucleons in a dense nucleus exceed 25 percent of the speed of light, turning the picture of a static nucleus on its head.
I do not understand how they claim the nucleons can travel FTL. Can anyone please explain? -Turnip

Exceeding 1/4 of the speed of light does not mean FTL!
antialias_physorg
5 / 5 (2) Mar 05, 2012
That nucleons are that fast is surprising. It was known that some electrons exhibit relativistic effect (the reason why gold - despit being a metal - does not look siver-ish like most other metals do)

Has anyone really thought in these terms since their first course in quantum mechanics?

It's really a hard sell to the layman. Humans tend to want to make analogies that we can relate to from everyday experiences (waves, particles, field 'lines', electrons and nucleans as balls with defined places and speeds, etc. )

It's really hard to let go of that and realize that what we use as analogies are emergent effects from more fundamental stuff - and therefore we cannot use them as analogies in this fundamental stuff.

I really love how Feynman expressed this:
I think it's at the end of this video, but I have no sound on this machine to verify that it's the correct one :-/
http://www.youtub...PId_6xec
Callippo
1 / 5 (2) Mar 06, 2012
We know about some examples of such atom nuclei already. For example, the spinning oxygen-16 nucleus can spread out into a linear chain of four clusters. http://physics.ap...v28/st10
Tausch
2.3 / 5 (3) Mar 07, 2012
Feynman. Correct. The scale we experience is still infinitely small to the rest (of whatever). "It's all there." - Feynman.
No matter how uncertain.
Shane_Fink
not rated yet Mar 12, 2012
Sigh didn't want to post here but no choice now, cheers and awesome discovery.

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