Difference between revisions of "Cross section"

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(Created page with "The '''cross section''' for a given process is a measure for the rate of interactions that orininate from the given process that can be quoted independently of the experimenta...")
 
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The '''cross section''' for a given process is a measure for the rate of interactions that orininate from the given process that can be quoted independently of the experimental set up of the scattering experiment itself. See wikipedia [https://en.wikipedia.org/wiki/Cross_section_(physics)]
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[[Category:Basic concept]]
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[[Category:Wikipedia]]
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The '''cross section''' for a given process is a measure for the rate of interactions that originate from the process that can be quoted independently of the experimental set-up of the scattering experiment itself. It is denoted <math>\sigma</math>. In a hypothetical experiment in which a flux of particles <math>F</math> (incident particles per unit area per unit time) scatter at a rate <math>R</math> (scattered particles per unit time), the cross section is <math>\sigma = R/F</math>.
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Cross sections are measured in units of area, where the special unit ''barn'' (b) is used with prefixes. A barn is 10<sup>−28</sup> m<sup>2</sup> (100 fm<sup>2</sup>). Cross sections at the [[LHC]] can range from hundreds of millibarns (the total cross section of proton-proton collisions) down to fb or smaller for rare processes that are still considered to be measurable.
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In calculations using [[natural units]] (with <math>\hbar = c = 1</math>), area has dimensions of 1/energy-squared, so units of [[GeV]]<sup>-2</sup> may be used. The conversion is 1 GeV<sup>-2</sup> = 0.389 mb.
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== Learn more ==
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* [https://en.wikipedia.org/wiki/Cross_section_(physics) Wikipedia article]

Latest revision as of 08:24, 7 April 2017

The cross section for a given process is a measure for the rate of interactions that originate from the process that can be quoted independently of the experimental set-up of the scattering experiment itself. It is denoted \sigma. In a hypothetical experiment in which a flux of particles F (incident particles per unit area per unit time) scatter at a rate R (scattered particles per unit time), the cross section is \sigma = R/F.

Cross sections are measured in units of area, where the special unit barn (b) is used with prefixes. A barn is 10−28 m2 (100 fm2). Cross sections at the LHC can range from hundreds of millibarns (the total cross section of proton-proton collisions) down to fb or smaller for rare processes that are still considered to be measurable.

In calculations using natural units (with \hbar = c = 1), area has dimensions of 1/energy-squared, so units of GeV-2 may be used. The conversion is 1 GeV-2 = 0.389 mb.

Learn more