Talk:Klein–Nishina formula
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The text states that:
"The value dσ/dΩ is the probability that a photon will scatter into the solid angle defined by dΩ = 2πsinθdθ."
A differential cross section is not a probability. It is an equivalent area for a target particle to scatter an incident particle into a given solid angle. As such, it is proportional to the probability that one of the incoming photons scatters into the solid angle.
Units
editI think the formula given is valid only in Lorentz-Heaviside units. It would have various factors of and floating around if it were written in SI or Gaussian units. I haven't made the changes myself as I'm not sure of my facts: I came to this article to find out for sure! Thanks. Matt (talk) 16:32, 4 January 2010 (UTC)
- As written, it's correct: all the weird unit conversion factors are buried inside the . The definition of the fine structure constant in terms of other constants depends on the unit system, but in any unit system it ends up as the unitless number about 1/137. Spatrick99 (talk) 21:31, 9 December 2010 (UTC)
Reference to the Compton scattering formula
editThe P(E,theta) is basically the compton scattering formula. I think this should be mentioned. Otherwise it is not clear where the expression for P is coming from. — Preceding unsigned comment added by 140.181.68.37 (talk) 09:27, 2 August 2013 (UTC)
To be honest, the whole wikipedia page should be re-written for this, or at least the equations, because the notation is more complicated than it needs to be. I do not see any sense for example why the letter P is used, it is not a standard practice anywhere at all, the "reduced" Compton wave length is NEVER indicated by the letter r, it should be a lambda (with a subscript of your choice as long as it's reasonably sensible). Indicating that P is a function of theta and E_gamma inside the Klein-Nishina formula itself, is again completely unnecessary, it just makes the equation look more cluttered for no good reason, furthermore it is not overly clear what P means in the formula, if you are not yet familiar with it, it would be much better to stick with E, E' and Eo, just like everywhere else. — Preceding unsigned comment added by 94.194.205.197 (talk) 03:03, 9 May 2014 (UTC)