Chapter 32, Problem 14Q

To determine

Why baryons have spin $\text{3}/\text{2 or }\mathrm{½}$ and mesons have spin $0\text{ or 1}$.

Answer to Problem 14Q

Solution:

Baryons have spin $1/\text{2 or 3/2}$ and mesons have spin $0\text{ or 1}$.

Explanation of Solution

Baryons consists of three quarks or antiquarks. The spin of each quark is $1/\text{2}$ and the spin of anti-quark is $-1/\text{2}$.

The possible spin configurations for baryons is,

• The spin of two quarks and one antiquark is $1/\text{2}$

• The spin of one quark and two anti-quarks is $-1/\text{2}$.

• The spin of three quarks is $3/\text{2}$.

• The spin of three anti-quarks is $-3/\text{2}$.

Mesons consists of two quarks or two anti-quarks. The spin of each quark is $1/\text{2}$ and the spin of anti-quark is $-1/\text{2}$.

The possible spin configurations for mesons is,

• The spin of two quarks is 1.

• The spin of two anti-quarks is -1.

• The spin of one quark and one anti-quark is 0.