Chapter 30.3, Problem 45SSC

To determine

To Explain: The way the given equations can be used to explain the radioactive decay of nucleon that results in the emission of a positron and a neutrino.

To Write: The equation in terms of nucleons instead of quarks.

Explanation of Solution

Introduction:

A proton is composed of 1 down quark and 2 up quarks. A neutron is composed of 2 down quarks and 1 up quark.

In beta-plus decay, 1 up quark converts to 1 down quark plus an intermediate ${\text{W}}^{\text{+}}$ boson. This is represented by first equation i.e. $\text{u}\to \text{d}+{\text{W}}^{+}$ . Then, this intermediate ${\text{W}}^{\text{+}}$ boson converts to a positron and a neutrino which is represented by the second equation i.e. ${\text{W}}^{+}\to {\text{e}}^{+}+\text{υ}$ .

A proton converts to a neutron, releasing a positron and a neutrino in a process called positron emission or beta-plus decay. This process can be expressed through an equation which is follows:

  $\text{p}\to \text{n}+{\text{e}}^{+}+\text{υ}$