3.2.1.5 Classification of particles

Question 1

What interaction are hadrons subject to?

Answer 1

Strong interaction

Question 2

What are the two classes of hadrons?

Answer 2

Baryons and mesons

Question 3

Give examples of baryons

Answer 3

Proton and neutron

Question 4

Give examples of antibaryons

Answer 4

Antiproton and antineutron

Question 5

Give examples of mesons

Answer 5

Pion and kaon

Question 6

What is baryon number?

Answer 6

A quantum number conserved in all interactions

Question 7

What is the baryon number of a proton or neutron?

Answer 7

Plus one

Question 8

What is the baryon number of an antiproton or antineutron?

Answer 8

Minus one

Question 9

What is the baryon number of a meson or lepton?

Answer 9

Zero

Question 10

State the conservation rule for baryon number

Answer 10

Baryon number is conserved in all interactions

Question 11

Which baryon is stable?

Answer 11

Proton

Question 12

What do unstable baryons decay into?

Answer 12

Eventually decay into a proton

Question 13

What is the exchange particle of the strong nuclear force?

Answer 13

Pion

Question 14

What is the kaon?

Answer 14

A meson that can decay into pions

Question 15

What are leptons?

Answer 15

Fundamental particles not subject to the strong interaction

Question 16

Give examples of leptons

Answer 16

Electron muon electron neutrino muon neutrino

Question 17

What are the antiparticles of leptons?

Answer 17

Positron antimuon electron antineutrino muon antineutrino

Question 18

What is lepton number?

Answer 18

A conserved quantum number assigned to leptons

Question 19

What is the electron lepton number of an electron?

Answer 19

Plus one

Question 20

What is the muon lepton number of a muon?

Answer 20

Plus one

Question 21

What are the lepton numbers of antiparticles?

Answer 21

Minus one for corresponding lepton type

Question 22

State the conservation rule for lepton number

Answer 22

Electron and muon lepton numbers are conserved separately in all interactions

Question 23

What does a muon decay into?

Answer 23

An electron a muon neutrino and an electron antineutrino

Question 24

What are strange particles?

Answer 24

Particles produced by the strong interaction and decaying via the weak interaction

Question 25

Give an example of a strange particle

Answer 25

Kaon

Question 26

What is strangeness?

Answer 26

A quantum number representing the presence of strange quarks

Question 27

How are strange particles produced?

Answer 27

In pairs via the strong interaction

Question 28

Is strangeness conserved in strong interactions?

Answer 28

Yes strangeness is conserved

Question 29

Can strangeness change in weak interactions?

Answer 29

Yes by 0 plus one or minus one

Question 30

Why does particle physics require collaboration?

Answer 30

Large teams of scientists and engineers are needed to validate new knowledge and experiments