Chapter 30, Problem 77A

(a)

To determine

To Find: The charge of a pion composed of given quarks.

Explanation of Solution

Given:

  $\text{u<mover accent="true"><mo>d </mo><mo>¯</mo></mover>}$

Formula Used:

The charge of the quarks would add up to become the net charge of the pion.

Calculations:

The charge of Up quark (u) is $+\frac{2}{3}e$ and anti-down quark is $+\frac{1}{3}e$ .

Thus, charge of pion composed of quarks $\text{u<mover accent="true"><mo>d </mo><mo>¯</mo></mover>}$ is: $+\frac{2}{3}e+\frac{1}{3}e=+1e$

Conclusion:

The charge of a pion composed of $\text{u<mover accent="true"><mo>d </mo><mo>¯</mo></mover>}$ is $+1e$ .

(b)

To determine

To Find: The charge of a pion composed of given quarks.

Explanation of Solution

Given:

  $\text{d<mover accent="true"><mo>u </mo><mo>¯</mo></mover>}$

Formula Used:

The charge of the quarks would add up to become the net charge of the pion.

Calculations:

The charge of down quark (u) is $-\frac{1}{3}e$ and anti-up quark is $-\frac{2}{3}e$ .

Thus, charge of pion composed of quarks $\text{u<mover accent="true"><mo>d </mo><mo>¯</mo></mover>}$ is: $-\frac{1}{3}e-\frac{2}{3}e=-1e$

Conclusion:

The charge of a pion composed of $\text{d<mover accent="true"><mo>u </mo><mo>¯</mo></mover>}$ is $-1e$ .