How to draw the angles of the CKM matrix?

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Discussion Overview

The discussion centers on the graphical representation of the CKM (Cabibbo-Kobayashi-Maskawa) matrix, particularly in relation to the angles associated with its three generations. Participants explore the possibility of visualizing the matrix in a way similar to the two-generation case, which involves a rotation between two orthonormal bases.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant inquires about the existence of a graphical representation for the CKM matrix that includes three angles, similar to the representation for the Cabibbo angle in the two-generation case.
  • Another participant notes that a three-generation CKM matrix would have eight dihedral angles and five constraints, questioning what such a representation would look like.
  • A third participant references the Wikipedia article, highlighting that for three generations, the CKM matrix includes three mixing angles and one CP-violating complex phase.
  • It is mentioned that in a general CKM matrix with n generations, the standard parameterization yields n(n-1)/2 angles, but the clarity of Euler angles in a visual representation is not obvious compared to the two-generation case.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the graphical representation of the CKM matrix and its angles, with multiple viewpoints on the complexity and feasibility of such a representation. No consensus is reached on the existence or form of a suitable graphical depiction.

Contextual Notes

The discussion highlights limitations in visualizing higher-dimensional representations and the complexity introduced by additional parameters in the CKM matrix.

Heidi
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Hi Pfs,
please look at the CKM article on wikipedia
https://en.wikipedia.org/wiki/Cabibbo–Kobayashi–Maskawa_matrix

It begins with the case of two generation (with the Cabibbo angle)
We have two orthonorma basis related by a rotation
https://en.wikipedia.org/wiki/File:Cabibbo_angle.svg

I wonder if such a graphical representation exists with the CKM matrix (with three angles)
we would have two (three dimensional) basis and each of of vector eigenstate woul be associated to the 3 angles. Have you ever seen such a picture?
 
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Such a body would have 8 dihedral angles and 5 constraints on these angles. That ignores the phase. What would such a thing even look like?
 
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I read this in the wikipedia article about the CKM matrix:
For the Standard Model case (n = 3), there are three mixing angles and one CP-violating complex phase.
 
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In the general case of a CKM matrix with n generation (n * n matrix)
the standard parameterization gives n(n-1)/2 angles but as it is a choice, it is not obvious
that the Euler angles appear clearly in a picture likr in tbe 2 * 2 case with its unique angle.
 

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