| Author |
Message |
RS
science forum beginner
Joined: 19 Jun 2005
Posts: 6
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 Posted: Sun Jun 19, 2005 5:35 am Post subject:
RMS Charge Radius of a Neutron
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I hope someone can assist me:
When I read scientific material about the "RMS Charge Radius of a Neutron",
it says that it has been precisely measured & is:
Rn = - 0.113 (fm^2)
How do you convert the negative radius squared to a positive one without it
becoming complex?
In other words, what is the radius in normal language [ "x" (fm)]?
Cheers .... RS |
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Arnold Neumaier
science forum Guru
Joined: 24 Mar 2005
Posts: 379
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| Posted: Sun Jun 19, 2005 10:24 pm Post subject:
Re: RMS Charge Radius of a Neutron
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RS wrote:
| Quote: | When I read scientific material about the "RMS Charge Radius of a Neutron",
it says that it has been precisely measured & is:
Rn = - 0.113 (fm^2)
|
Please quote the source of this statement, preferably a document
available online.
Arnold Neumaier |
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FrediFizzx
science forum Guru
Joined: 01 May 2005
Posts: 774
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| Posted: Mon Jun 20, 2005 9:31 pm Post subject:
Re: RMS Charge Radius of a Neutron
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"Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> wrote in message
news:42B51E54.1090408@univie.ac.at...
| RS wrote:
|
| > When I read scientific material about the "RMS Charge Radius of a
| > Neutron", it says that it has been precisely measured & is: Rn = -
| > 0.113 (fm^2)
|
| Please quote the source of this statement, preferably a document
| available online.
Here is one from the Particle Data Group,
http://pdg.lbl.gov/2004/listings/s017.pdf
or postscript
http://pdg.lbl.gov/2004/listings/s017.ps
FrediFizzx |
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Jay R. Yablon
science forum Guru Wannabe
Joined: 17 Jun 2005
Posts: 176
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| Posted: Tue Jun 21, 2005 7:16 am Post subject:
I'd love the see the same thing
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By the way, one thing that is limiting in the research that Dr. Inopin and I
have submitted at http://arxiv.org/pdf/hep-ph/0506166 is that there do not
seem to be any good experimental catalogs (at least that we could find) of
baryon and meson radii. Does anyone one of such a catalog? I'd really love
especially to have the neutron data. This may be because the experimental
data about these particle radii is spotty, but it would be great to have
this experimental data.
Jay.
--
_____________________________
Jay R. Yablon
910 Northumberland Drive
Schenectady, New York 12309-2814
Phone / Fax: 518-377-6737
Email: jyablon@nycap.rr.com
"RS" <zordan@ozemail.com.au> wrote in message
news:jqyse.629$i8.4548@nnrp1.ozemail.com.au...
| Quote: | I hope someone can assist me:
When I read scientific material about the "RMS Charge Radius of a
Neutron",
it says that it has been precisely measured & is:
Rn = - 0.113 (fm^2)
How do you convert the negative radius squared to a positive one without
it
becoming complex?
In other words, what is the radius in normal language [ "x" (fm)]?
Cheers .... RS
|
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|
| Back to top |
|
|
Arnold Neumaier
science forum Guru
Joined: 24 Mar 2005
Posts: 379
|
| Posted: Wed Jun 22, 2005 1:00 am Post subject:
Re: RMS Charge Radius of a Neutron
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|
FrediFizzx wrote:
| Quote: | "Arnold Neumaier" <Arnold.Neumaier@univie.ac.at> wrote in message
news:42B51E54.1090408@univie.ac.at...
| RS wrote:
|
| > When I read scientific material about the "RMS Charge Radius of a
| > Neutron", it says that it has been precisely measured & is: Rn = -
| > 0.113 (fm^2)
|
| Please quote the source of this statement, preferably a document
| available online.
Here is one from the Particle Data Group,
http://pdg.lbl.gov/2004/listings/s017.pdf
or postscript
http://pdg.lbl.gov/2004/listings/s017.ps
|
Thanks. In the introduction of
S. Kopecky et al
Phys. Rev. C 56, 2229–2237 (1997)
(which the PDG source quoted refers to), one can read:
''The charge radius of the neutron <r_n^2> or the mean squared charge
radius is described by the volume integral over the neutron
integral rho(r)r2dtau, where r is the distance to the center of
the neutron and rho(r) is the charge density.
Positive as well as negative values of rho(r) will occur coming
from the distributions of valence quarks and the negative p-meson
cloud outside.
Since r(r) is negative for larger r values, caused by the meson cloud,
the r^2 dependence of the integral will lead to a negative value of
<r_n^2>.''
Arnold Neumaier |
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