describe the changes to quark composition that take place during β– and β+ decay

Fundamental Particles: Quarks and Beta Decay

What are Quarks? 🔬

Quarks are the building blocks of protons and neutrons. Think of a proton as a word made from letters (quarks). There are six types (flavours) of quarks, but only two are common inside nuclei: the up quark ($u$) and the down quark ($d$). A proton is made of two up quarks and one down quark ($uud$), while a neutron is two down quarks and one up quark ($udd$).

Beta‑Minus Decay (β–) ⚛️

During β– decay, a neutron turns into a proton. Imagine swapping one letter in the word “neutron” to make “proton.” The change happens at the quark level: a down quark ($d$) inside the neutron changes into an up quark ($u$). This is like turning a “d” into a “u”. The process also releases an electron ($e^-$) and an antineutrino ($\bar{u}_e$).

1. A down quark emits a $W^-$ boson and becomes an up quark.
2. The $W^-$ boson quickly decays into an electron ($e^-$) and an antineutrino ($\bar{u}_e$).

Beta‑Plus Decay (β+) ⚛️

In β+ decay, a proton turns into a neutron. Think of changing a letter in “proton” to make “neutron.” Here, an up quark ($u$) inside the proton changes into a down quark ($d$). This emits a positron ($e^+$) and a neutrino ($u_e$).

1. A up quark emits a $W^+$ boson and becomes a down quark.
2. The $W^+$ boson quickly decays into a positron ($e^+$) and a neutrino ($u_e$).

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