Nuclear and Quantum Physics - Structure of Matter

The Rutherford-Geiger-Marsden experiment provided evidence for the nuclear model of the atom, showing that the nucleus is small, dense, and positively charged, as most $\alpha$-particles passed through gold foil while a few were deflected at large angles.

Nuclide notation is written as $^A_Z X$, where $A$ is the nucleon (mass) number and $Z$ is the atomic (proton) number. Isotopes are atoms of the same element with the same $Z$ but different $A$.

Hadrons are particles made of quarks. They are subdivided into Baryons (made of 3 quarks, e.g., protons $uud$ and neutrons $udd$) and Mesons (made of one quark and one anti-quark).

Leptons are fundamental particles that do not experience the strong nuclear force. Examples include the electron ($e^-$), muon ($\mu$), tau ($\tau$), and their associated neutrinos ($\nu_e, \nu_{\mu}, \nu_{\tau}$).

Quarks carry fractional charges: up ($u$), charm ($c$), and top ($t$) have a charge of $+\frac{2}{3}e$; down ($d$), strange ($s$), and bottom ($b$) have a charge of $-\frac{1}{3}e$.

The four fundamental forces and their exchange particles (gauge bosons) are: Electromagnetic (photons $\gamma$), Strong (gluons $g$), Weak ($W^+, W^-, Z^0$ bosons), and Gravitational (graviton).

Conservation laws: In any nuclear reaction, charge ($Q$), baryon number ($B$), lepton number ($L$), and mass-energy must be conserved. Strangeness ($S$) is conserved in strong and electromagnetic interactions but can change by $\pm 1$ in weak interactions.

Confinement: Quarks cannot exist in isolation because the force between them increases as they are pulled apart. The energy required to separate them creates a new quark-antiquark pair (pair production).