Question

Sketch Feynman vertex for the creation of a $\underset{d}{\leftarrow }$ quark and c quark.

Short answer

The Feynman diagram is shown in the figure as:

Step-by-step solution

Given data

The $\underset{d}{\leftarrow }$ has charge $+1/3$, and c has charge $+2/3$ .

Concept of Feynman diagram 

A Feynman diagram describes the interactions in quantum field theory. Solid lines, and curved lines are used to represent different types of particle interactions.

Step 3:Sketch Feynman vertex 

The Feynman diagram is shown in figure 1.

Figure 1

Because the type of quark changed, it is a weak interaction.

Because$\underset{d}{\leftarrow }$has charge$+1/3$, and c has charge $+2/3$, they will exchange a${\text{W}}^{+}$ boson.