- #31
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Two different threads on the same topic have been merged.
Zz.
Zz.
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Recent findings suggest that the proton's charge radius is approximately 4% smaller than previously estimated, raising questions about the accuracy of quantum electrodynamics (QED) calculations. While QED has effectively calculated the Lamb shifts for hydrogen and helium, discrepancies in muonic hydrogen measurements may indicate potential errors in recoil corrections or other factors. The charge radius, crucial for determining the Rydberg constant, has been consistently defined across various experimental methods, yet the new measurement challenges established values. Discussions highlight the need for further investigation into the implications of this size reduction on proton properties and the accuracy of QED. Overall, the findings could signal the need for a reevaluation of fundamental constants and theoretical models in particle physics.
- #32
petergreat
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Forgive me for asking a naive question. Is it possible to determine the proton size using muon-proton scattering in an accelerator? Would this method be sufficiently accurate to shed light on this problem?
- #33
sanman
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Proton Smaller Than Previously Thought?
There have been a spate of articles about the size of the proton being measured as smaller than previously believed:
http://arstechnica.com/science/news/2010/07/-we-may-have-been.ars
What is the significance of this finding? What impact does it have on the broader picture?
This sounds like some basic things in physics are going to have to be revised, no matter what.
Does this affect things like nuclear cross-section values for nuclear energy applications?
There have been a spate of articles about the size of the proton being measured as smaller than previously believed:
http://arstechnica.com/science/news/2010/07/-we-may-have-been.ars
What is the significance of this finding? What impact does it have on the broader picture?
This sounds like some basic things in physics are going to have to be revised, no matter what.
Does this affect things like nuclear cross-section values for nuclear energy applications?
- #34
jtbell
Staff Emeritus
Science Advisor
Homework Helper
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Threads merged. Sanman, check out the previous posts. I left your post intact because it has a reference to another article on the subject.
- #35
sanman
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jal said:
What about experimenting with μ+ and the anti-proton?
Shall we hope for similar results there? Or could you see a CP-violation on top of everything?
- #36
Dadface
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sanman said:
Interesting I think but so incredibly difficult and I would guess impossible at the present time.Just one problem that comes to mind is how are you going to get and keep a sufficient supply of anti protons or anti hydrogen?Another incredibly difficult experiment would be to test tauonic hydrogen.Experiments for the future perhaps.
- #37
Orion1
- 961
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Rydberg constant...
Was the Rydberg constant and proton radius QED equation published in the Nature article?
Does anyone disagree with this quantum mechanical definition of the Rydberg constant?
Rydberg constant:
R_\infty = \frac{m_e e^4}{8 \epsilon_0^2 h^3 c}
[/Color]
Reference:
http://en.wikipedia.org/wiki/Rydberg_constant"[/URL]
http://www.nature.com/nature/journal/v466/n7303/abs/nature09250.html"
[URL]http://books.google.com/books?id=DliKdTg8GHQC&pg=PA146"[/URL]
Nature said:
Was the Rydberg constant and proton radius QED equation published in the Nature article?
Does anyone disagree with this quantum mechanical definition of the Rydberg constant?
Rydberg constant:
R_\infty = \frac{m_e e^4}{8 \epsilon_0^2 h^3 c}
[/Color]
Reference:
http://en.wikipedia.org/wiki/Rydberg_constant"[/URL]
http://www.nature.com/nature/journal/v466/n7303/abs/nature09250.html"
[URL]http://books.google.com/books?id=DliKdTg8GHQC&pg=PA146"[/URL]
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