User talk:Benjonson

Your edit at quark

Dear benjonson,

You apparantly tried to send me a message, which somehow ended up on user:Aua talk page instead of mine. So I will just copy it here:

Greetings,

I don't understand you undid why my changes to the CKM matrix (http://en.wikipedia.org/wiki/Quark). It seems to me either the CKM matrix has to be changed, or the accompanying "pictorial representation" must be changed. You say "the entries are not the decay rates". That may be true if you are referring to a technical use of "decay rates". But according to the text, "Vij relates to the tendency that a quark of flavor i will change into a quark of flavor j". Are you really suggesting that it is most likely that an up quark will change to a down quark (opposite of beta decay), for example? Then I would think you must reverse the arrow in the drawing. But I think the drawing is right and the matrix has errors. Sorry if I am being dense here... Can you clarify?

Thanks,

Benjonson (talk) 7:44 pm, 22 May 2009, Friday (10 days ago) (UTC+2)

I try to clarify. The thing is that the CKM matrix does not distinguish between a change i->j and a change j->i. The entry V_ij just gives the 'relative strength' of these processes. The actually probability of a certain decay happing depends on a number of other factors most notably the masses of the involved particles. Decay processes become more probable as the decay products become less massive, and it is impossible for the decay products to be more massive then the decaying particle. Hence it is impossible for a bottom quark to decay into a top quark. The picture with the arrows shows the decay rates. The text is not completely clear on this point, but I think it has been tweaked a bit to better reflect this since your edit. Please let me know if it still is confusing to you. If so we will try to add some note or something to make it more clear. (TimothyRias (talk) 09:41, 31 May 2009 (UTC))