Classification Of Particles Flashcards
Hadrons aren’t fundamental particles. They’re made up of smaller particles called what
Quarks
HADRON are particles that feel the what
STRONG NUCLEAR FORCE
Not all particles can feel it
What are the two types of hadrons called
Baryons
Mesons
How are baryons and mesons classified
Number of QUARKS that make them up
Name 2 baryons
PROTONS & NEUTRONS (nucleons)
Name a baryons which isn’t a nucleon
Sigmas (they’re short lived)
Name the ONLY stable baryon
Proton (won’t decay as far as we know)
All baryons (apart from proton) are unstable so decay to become other particles. What does the particle the baryon ends up as depends on
What it STARTED AS but always includes a PROTON
Name 2 antibaryons
ANTIPROTONS and ANTINEUTRONS
Don’t find antibaryons in ordinary matter as they are annihilated when they meet their corresponding particle
What is the number of baryons in an interaction called
Baryon number
What do the (anti)proton and (anti)neutron each have a baryon number of
+1 (-1)
In an interaction, the baryon number on either side of the equation MUST be ….
The same
Neutrons decay into what
Protons
What type of interaction is beta decay caused by
WEAK interaction
When a neutron decays (beta-minus), what does it form
Proton
Electron
Antineutrino
Name 2 mesons
Pions & kaons
Are all mesons stable or unstable
Unstable
State 2 facts about the pions
1) The lightest meson
2) Discovered in cosmic rays
Where do you find many pions
In HIGH-ENERGY particle collisions like those studied at the CERN PARTICLE ACCELERATOR
Kaons are ….. And more ….. Than pions
Heavier
Unstable
What do mesons and baryons interact via
THE STRONG NUCLEAR FORCE
What do pion interactions swap
PROTONS with NEUTRONS and NEUTRONS with PROTONS
but leave the overall baryon number the same
Leptons are ….. Particles and don’t feel the ….
Fundamental
STRONG NUCLEAR FORCE
How do leptons only really interact via
Weak interaction
Along with a bit of gravitational force and the electromagnetic force as well if they’re charged
Name the 3 types of leptons
Electrons
Muon & Tau (heavier electrons)
…. Are stable, ….. And ….. Are unstable
Electrons
Muons
Tau
What do muons and taus decay eventually into
Ordinary electrons
Neutrinos have zero what
MASS (almost) & ELECTRIC CHARGE
Neutrinos only take part in what type of interaction
Weak interaction
A neutrino can pass right through the earth without anything happening to it
What is each laptop given a lepton number of
1
Le,Lmue,Ltau (separately)
What is the charge of a lepton
-1
Unless it is a (stated lepton)-neutrino where the charge would be 0
