Chapter 32, Problem 40P

To determine

The quark combination needed to produce a ${\text{D}}^0$ meson.

Answer to Problem 40P

Solution:

The quark combination needed to produce ${\text{D}}^0$ meson is .

Explanation of Solution

All quarks have spin and an electric charge of either $+\frac{2}{3}e$ or $-\frac{1}{3}e$. Antiquarks have opposite sign of electric charge $Q$, baryon number $B$, strangeness $S$, charm $c$, bottom $b$, and top $t$.

To produce a ${\text{D}}^0$ meson, the total charge on the quark combination must be zero. Also the value of the baryon number $B$ is $0$, and the value of strangeness $S$ must be $0$ but the value of charm $c$ must be $+1$ as per condition. So, there must be a c quark with a charge of $+\frac{2}{3}e$. To neutral a meson, there must be another quark with a charge of $-\frac{2}{3}e$. So, the second quark must be an antiquark. The only combination with those properties is an anti-up quark. Hence required combination of the quark is .