- #1
Ajihood
- 11
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Homework Statement
Hi guys, I have been given the problem of drawing the feyman diagrams and finding the decay rates for the two decays:
D0 [tex]\rightarrow[/tex] K+ + [tex]\pi[/tex]-
and
D0 [tex]\rightarrow[/tex] K- + [tex]\pi[/tex]+
D0 [tex]\rightarrow[/tex] [tex]\pi[/tex]- + [tex]\pi[/tex]+
Homework Equations
The coupling constant g = 10^-5 for the weak force. But we have quarks changing so we have sin[tex]\vartheta[/tex]c and cos[tex]\vartheta[/tex]c facotrs associated with the cabbibo matrix. We take [tex]\vartheta[/tex]c = 12.7 degrees.
The Attempt at a Solution
I have no problem drawing the feynman diagram for the second decay, with c [tex]\rightarrow[/tex] s and the W+ decaying to u and anti d. This has a coupling constant
The problem is with the first equation. I can get it if I have c [tex]\rightarrow[/tex] d and then W+ decaying to u and anti s.
This is my problem. Can W+ decay to a u and anti-s. All the examples I find on the net have W boson decaying to a quark and anti-quark in the same generation... Can I do this?
I can get the third decay easy, but it is the same as the second with W+ decaying to u and anti-d. It just worries me it is so similar.
So am I on the right track?
Thanks in advanced.