Question

(a) What particle has the quark composition $\overline{\mathrm{u}}\overline{\mathrm{u}}\overline{\mathrm{d}}$?

(b) What should its decay mode be?

Short answer

(a) The particle having the quark composition$\overline{u}\overline{u}\overline{d}$is an antiproton.

(b) The decay mode of antiproton should be ${\pi }^0+{\mathrm{e}}^{-}$.

Step-by-step solution

Concept Introduction

A quark is a basic ingredient of matter and a sort of elementary particle.

Antiquarks are the antiparticles that correspond to each flavour of quark.

Particle with quark composition $\overline{\mathrm{u}}\overline{\mathrm{u}}\overline{\mathrm{d}}$

(a)

From the table$33.4$, we can see that the quark composition of a proton is given by$p=uud$; and since antibaryons have the antiquarks of their counterparts, then the antiproton is given by$\overline{p}=\overline{u}\overline{u}\overline{d}$.

Therefore, the particle is an antiproton.

Decay mode of Antiproton

(b)

Proton particle decay as follows;

$p\to {\pi }^0+e^{+}$

Anti particle will decay as follows;

$\bar{p}\to {\pi }^0+e^{-}$

Therefore the decay mode antiproton is $\bar{p}\to {\pi }^0+e^{-}$.