# Order of the symmetry group of Feynman Diagrams

1. Nov 3, 2014

### Breo

Hello,

I am learning Feynman diagrams and I still do not understad quite well the symmetry factor idea. The equation is:

$$\frac{1}{O(G)} = \frac{M}{n!(4!)^n}$$

I was trying the next example:

If I am not wrong it is O(G) = 10 taking care of the asymmetry of each pair of internal lines connecting vertices.

2. Nov 3, 2014

### Breo

Now, I count S = O(G) = 12.

3. Nov 22, 2014

### Breo

Can anyone at least explain "for dummies" how to count the order of symmetry?