8.6 Mesons and Baryons

Question 1

What is a hadron?

Answer 1

particles made up of quarks

Question 2

What are the 2 types of hadrons?

Answer 2

Mesons and baryons

Question 3

How are hadrons classified?

Answer 3

By number of quarks that make them up

Question 4

How many quarks or antiquarks make up a baryon?

Answer 4

3

Question 5

What are two baryons I have to know about?

Answer 5

Proton and Neutron

Question 6

What is a proton made up of ?

Answer 6

up up down

Question 7

What is a neutron made up of?

Answer 7

down down up

Question 8

What is an anti particle of proton made up of?

Answer 8

anti up anti up anti down

Question 9

What is an anti particle of neutron made up of?

Answer 9

anti down anti down and anti up

Question 10

Can anti quarks and quarks be mixed to make up a baryon?

Answer 10

Nope!

Question 11

What is the only stable baryon?

Answer 11

Proton, as far as we know it doesn’t decay

Question 12

Does a neutron decay?

Answer 12

Yes, if it is free

Question 13

Are the antiparticles of protons and neutrons baryons?

Answer 13

Yes

Question 14

In a particle interaction is the baryon number always conserved?

Answer 14

Yes, the same number must be present either side

Question 15

What is the baryon number of a proton and a neutron?

What about their antiparticles?

Answer 15

1

-1

Question 16

A baryon containing a single strange quark has what symbol to represent it ?

Answer 16

sigma

Question 17

A baryon containing 2 strange quarks is a what ?

Answer 17

An xi

Question 18

A baryon containing 3 strange quarks is called a what ?

Answer 18

An omega

Question 19

What is a meson?

Answer 19

Hadron made up of 2 quarks, a combination of a quark and antiquark

Question 20

Are all mesons unstable?

Answer 20

yes

Question 21

What is the group of mesons I have to know about?

Answer 21

Pions

Question 22

What are the versions of pions i have to know about?

Answer 22

π+  = u and anti d 
π0 = u and anti u
π0 = d and anti d 
π- = down and anti u

Question 23

What is the names of mesons with one strange quark?

Answer 23

a kaon

Question 24

Name of meson with 2 strange quarks?

Answer 24

eta meson symbol = η0

Question 25

What are the 4 conservation laws of particle interaction equations? - apply to fundamental particles

Answer 25

• conserved baryon number
• conserved charge
• lepton number is conserved
• strangeness number is conserved

Question 26

Lightest type of mesons?

Answer 26

Pions