1.2 The Particle Zoo

Question 1

Name 4 leptons and their charges

Answer 1

Neutrino 0
Electron -1
Muon -1
Tau -1

Question 2

What do all baryons eventually decay to?

Answer 2

Protons

Question 3

Name 2 baryons and their quark structures

Answer 3

Proton uud

Neutron udd

Question 4

Through what interactions are mesons produced and decay?

Answer 4

Produced by the strong force, decay by the weak force

Question 5

Name 2 mesons and their charges

Answer 5

Pion +1/-1/0

Kaon +1/-1/0

Question 6

What can kaons decay into that other particles can’t?

Answer 6

Other mesons, specifically pions

Question 7

What are the 6 quarks?

Answer 7

Up, down, strange, (charm, top, bottom)

Question 8

What is the charges of up, down and strange quarks?

Answer 8

Up +2/3
Down -1/3
Strange -1/3

Question 9

What is the baryon number of all quarks?

Answer 9

1/3

Question 10

What is the strangeness of a strange quark?

Answer 10

-1

Question 11

What is the quark structure of baryons?

Answer 11

3 quarks or 3 antiquarks

Question 12

What is the quark structure of mesons?

Answer 12

A quark and an antiquark

Question 13

Why do pion 0’s annihilate instantly?

Answer 13

Because they are made of a quark and it’s antiquark

Question 14

When is strangeness conserved?

Answer 14

Strangeness is conserved in the strong interaction but not in the weak interaction

Question 15

What 2 things can happen in the strong interaction?

Answer 15

Quarks can be rearranged

Pairs of quarks can be annihilated to make other products

Question 16

What happens in weak interactions?

Answer 16

Quarks are converted to a different quark e.g uud to udd in positron emission

Question 17

What 6 quantities are conserved in all interactions?

Answer 17

Energy, mass, momentum, charge, baryon and lepton number