Particle Physics

A basic and very popular science-y book that gives an alright general introduction to particle physics.

Particles and forces

Force	Particle	Experiences	Theory
Electromagnetic	photon ($\gamma$)	Gravity	QED
Gravity	?	?	?
Strong	gluons	Gravity, Strong	QCD
Weak (charged)	$W^\pm$	Gravity, Weak, EM	EWT
Weak (neutral)	$Z^0$ bosons	Gravity, Weak	EWT

• A Grand Unified Theory (GUT) is a theory unifying the three forces: EM, S, W.
• The weak interaction breaks parity and charge parity symmetry
• The Higgs-field (and particle) endow other particles with mass

Beta-decay - $\beta$

Transition between nucleons bound in atoms.

TODO: Beta-decay

Standard Model

Particle numbers

• electric charge
• weak isospin
• baryon number
• lepton umber
• strangeness
• charm
• bottomness
• topness
• colour charge

Particle types

• Generation - Family of quarks and leptons: 2x quark + 2x lepton
• Boson - Integer spin
• Fermion - Half-integer spin
• Gauge boson - Force carrier
• Lepton - Spin-$\frac{1}{2}$ particle, no strong interaction
• Hadron - Quark composite
  • Baryon - Three quark composite
    • Nucleon - protons + neutrons (u/d-quarks)
    • Hyperons - non-zero strangeness
  • Meson - Quark, anti-quark composite (hadron)

The 6 flavours of quarks account for the over 200 known mesons and baryons.

Other particles

• kaon
• $J/\psi$ particle - First discovered charmonium particle
• neutrino
• muon
• neutron/proton
• pion - lightest meson
• tauon - heaviest lepton

Extracts

1. Every second, somewhere between $10^13$ and $10^14$ neutrinos from the Sun pass through our bodies with minimal interactions, doing us no harm.

   p. 4

2. Unlike the electron, the muon and the tauon are unstable and spontaneously decay via the weak innteraction. They play no roles in everyday matter and why they appear in nature is a puzzle.

   p. 6