Higher-order weak interaction decays

• MaximumTaco
In summary, the decay of the B+ meson into a D0 meson and a pi+ meson occurs through a weak interaction involving multiple W boson exchanges. The process involves the quarks u, b, c, and d, and is difficult to represent with a Feynman diagram. Although it may not occur in practice, it could potentially happen through a series of complicated steps involving weak interactions and strong interactions.

MaximumTaco

Considering the decay of certain exotic mesons, such as the following:

$$B^{+} --> D^{0} \pi^{+}$$

Apparently the decay proceeds via a weak interaction where multiple W boson exchanges occur.

I was trying to nut out how this actually occurs, and draw up a sensible Feynman diagram representation of the process, but i can't quite nut it out.

Recall that the B+ meson is comprised of a u and anti-b quark, and the D0 is a c and anti-up, and the Pi+ is an up and anti-down, FYR.

Could someone offer me any pointers as to how such decay process usually work? First-order weak process such as beta decay are pretty straightforward, but this idea seems a bit more tricky.

bbar-->cbar + W^+.
W^+--> u + dbar.
That u + cbar--> D^0.
The incoming u + dbar--> pi^+.

But doesn't the D^0 meson contain a c, not a cbar ?

Yes. You fooled me with your first equation. It should be
B^+--D^0bar+pi^+.
If you really meant D^0, then the diagram would be a mess and the decay never seen unless you have some completely new theory.

Could you tell me how the decay could proceed anyway, even though it might never occur in practice?

The final state you want, D_0 + pi^+ has the quarks [c ubar] and
[u dbar]. You could get that from [u bbar] by the steps:
1. bbar -->W^+ + cbar.
2. W^+ -->[c] + [dbar].
3. cbar --> W^- + dbar.
4. W^- + u --> d.
5. dbar +d --> [ubar] + (via strong intgeraction).
This leaves you with the right quarks for D_0 + pi^+.
The decay is doubly weak, so I cannot see how it could be observed.

1. What are higher-order weak interaction decays?

Higher-order weak interaction decays are decay processes that involve a higher number of particles in the final state compared to the standard weak interaction decay. In these decays, the weak interaction between particles is responsible for the decay, but it involves multiple interactions instead of just one.

2. How are higher-order weak interaction decays different from standard weak interaction decays?

The main difference between higher-order weak interaction decays and standard weak interaction decays is the number of particles involved in the decay process. Higher-order decays involve more particles in the final state, which makes them more complex and difficult to study compared to standard decays.

3. What is the significance of studying higher-order weak interaction decays?

Studying higher-order weak interaction decays is important for better understanding the fundamental interactions and forces in the universe. These decays can provide valuable information about the properties of particles and their interactions, which can help in developing new theories and models in particle physics.

4. How are higher-order weak interaction decays observed and measured?

Higher-order weak interaction decays are observed and measured using particle accelerators, such as the Large Hadron Collider (LHC) at CERN. The particles involved in the decay process are accelerated to high energies and then allowed to collide, producing a variety of particles in the final state. Scientists then use advanced detectors to measure the properties of these particles and reconstruct the decay process.

5. What are some examples of higher-order weak interaction decays?

Some examples of higher-order weak interaction decays include the decay of a top quark into a bottom quark and a W boson, the decay of a Higgs boson into two Z bosons, and the decay of a W boson into a lepton and multiple quarks. These decays have been studied extensively at the LHC and have provided important insights into the fundamental interactions of particles.