Particles Flashcards
What are the three types of fundamental particles?
Hadrons
Leptons
Quarks
How are hadrons classified?
Experience the strong force
Baryons(3 quarks)
Mesons(1 quark and 1 antiquark)
How are leptons classified?
Do not experience a strong force
Examples: electrons, muons, neutrinos
How are quarks classified?
Fundamental building blocks of hadrons
Six types: up, down, strange, charm, top, bottom
What are the four fundamental forces?
Strong nuclear force
Electromagnetic force
Weak nuclear force
Gravitational force
What does strong nuclear force do and what particles mediate it?
Holds nucleons together
Exchange particles: Gluon
What does an electromagnetic force do and what particles mediate it?
Acts on charged particles
Exchange particle: Photon
What does weak nuclear force do and what particles mediate it?
Causes beta decay
Exchange particles: W+, W-, Z bosons
What does a gravitational force do and what particles mediate it?
Acts on mass, weakest force
Exchange particles: Graviton
What happens during beta-minus decay?
Neutron-> Proton
Electron and antineutrino emitted
Quark change: Down -> Up
What happens during beta-plus decay?
Proton->Neutron
Positron and neutrino emitted
Quark change: Up-> Down
What is annihilation?
A particle and its antiparticle collide, producing two gamma photons
What is pair-production?
A high-energy photon creates a particle-antiparticle pair
What is the equation for annihilation?
E=m(c^2)
What is the equation for pair production?
E=(2m(c^2))
What are strange particles?
They contain a strange quark and are produced via the strong interaction
Decay via the weak interaction, meaning strangeness is not always conserved
What conservation laws of strange particles must be obeyed?
Conserved in all interactions:
Charge
Baryon number
Lepton number
Strangeness:
Conserved in strong interactions
Can change by +-1 in weak interactions
