2 Quarks and Leptons Flashcards
what are cosmic rays?
high energy particles (fast moving protons or small nuclei) that travel through space from the stars
what is created when cosmic rays crash into the gas particles in the atmosphere?
new short lived particles and antiparticles as well as photons
what are the properties of the muon?
- negatively charged
- rest mass of over 200 times that of an electron
what are the properties of the pion (or pi meson)?
- can be positively or negatively charged or neutral
- rest mass is greater than a muon but less than a proton
what are the properties of a kaon (or K meson)?
- can be positively or negatively charged or neutral
- rest mass greater than a pion but less than a proton
what are strange particles?
particles which decay into pions and take longer to decay than expected
what can kaons decay into?
pions or a muon and an antineutrino or an antimuon and a neutrino
what do muons decay into?
an electron and an antineutrino
antimuons decay into a positron and a neutrino
what do charged pions decay into?
- a muon and an antineutrino
- an antimuon and a neutrino
what do neutral pions decay into?
high energy photons
What are hadrons?
Particles and antiparticles that can interact through the strong interaction
What are leptons?
Particles and antiparticles that do not interact through the strong interaction
What is a baryon?
Protons and other hadrons that decay into protons, either directly or indirectly
What are mesons?
Hadrons that do not include protons in their decay products (kaons and pions)
Why are there different types of neutrinos?
The neutrinos and antineutrinos produced in beta were different from those produced by muon decays
What are the two types of neutrinos?
Electron neutrinos and muon neutrinos
What can a neutrino or antineutrino do in interaction between a lepton and a hadron?
They can change into or form a corresponding charged electron
What happens during muon decay?
- The muon changes into a muon neutrino
- An electron is created and corresponding antineutrino is also created
When is strangeness conserved?
During the strong interaction
What is the quark composition of mesons?
A quark and an antiquark
What is the quark combination of baryons?
Three quarks
What happens in terms of quarks in beta plus decay?
Are down quark in the neutron changes to an up quark
A beta plus particle and a neutrino is also emitted
What happens in terms of quarks during beta plus decay?
And up quark in the proton changes to a down quark in the neutron
A beta plus particle and a neutrino are also emitted
What is conserved during all particle interactions?
Energy
Charge
Lepton number
Baryon number
