3.2.1.6 Quarks and Antiquarks

Question 1

What are quarks?

Answer 1

Quarks are fundamental particles which make up the hadrons.

Question 2

What are three types of quark, and what are there three antiquarks?

Answer 2

Up quark (u)
Down quark (d)
Strange quark (s)

Question 3

What is the quark composition of the baryons?

Answer 3

Proton = up, up, down
Anti proton = anti up, anti up, anti down.
Neutron = up, down, down
Anti Neutron = anti up, anti down, anti down.

Question 4

What are the quark compositions of the pions?

Answer 4

Pion + = up, anti down
Pion 0 = up, anti up or down, anti down or strange, anti strange.
Pion - = down, anti up.

Question 5

What are the quark compositions of the kaons?

Answer 5

Kaon + = up, anti strange
Kaon 0 = down, anti strange.
Anti Kaon 0 = strange, anti down.
Kaon - strange, anti up

Question 6

What are the three main properties of quarks and antiquarks?

Answer 6

Relative Charge
Baryon Number
Strangeness.

Question 7

What is the property of quarks and relative charge?

Answer 7

All quarks and antiquarks carry a charge which is a fraction of the charge of an electron.

Question 8

What is the property of quarks and baryon number?

Answer 8

All quarks and antiquarks have a baryon number. The baryon number of a quark is + 1/3, and the baryon number of an antiquark is -1/3.

Question 9

What is the property of quarks and strangeness?

Answer 9

All quarks and antiquarks have a strangeness of 0, except the strange quark (-1) and the antistrange quark (+1).

Question 10

What quark properties must be conserved in all interactions?

Answer 10

Relative Charge and Baryon Number must always be conserved.

Question 11

What is the rule for conservation of strangeness for quarks?

Answer 11

Strangeness must be conserved in all interactions involving the nuclear strong force.
Strangeness may be conserved or change by +/- 1 in weak interactions.

Question 12

What are the properties of an up quark?

Answer 12

Symbol = u
Charge = 2/3
Baryon Number = 1/3
Strangeness = 0

Question 13

What are the properties of an anti-up quark?

Answer 13

Symbol = u with a line on the top
Charge = -2/3
Baryon Number = -1/3
Strangeness = 0

Question 14

What are the properties of a down quark?

Answer 14

Symbol = d
Charge = -1/3
Baryon Number = 1/3
Strangeness = 0

Question 15

What are the properties of an anti-down quark?

Answer 15

Symbol = d with a line on the top.
Charge = 1/3
Baryon Number = -1/3
Strangeness = 0

Question 16

What are the properties of a strange quark?

Answer 16

Symbol = s
Charge = -1/3
Baryon number = 1/3
Strangeness = -1

Question 17

What are the properties of an anti-strange quark?

Answer 17

Symbol = s with a line on the top.
Charge = 1/3
Baryon Number = -1/3
Strangeness = +1

Question 18

What are mesons made of?

Answer 18

All mesons are made up one quark and one antiquark.

Question 19

Which quarks are pions made?

Answer 19

Pions are made up combinations of up, down, anti-up, and anti-down quarks.

Question 20

What quarks are kaons made of?

Answer 20

Kaons are made up of combinations of all quarks, including strange and anti-strange quarks.

Question 21

What is quark confinement?

Answer 21

Quark confinement is the fact that it is not possible to get a quark on its own by itself.

Question 22

What would happen, in terms of quarks, if you blasted a proton with a lot of energy?

Answer 22

A single quark would not be removed. The energy that was supplied would just be converted into mass. `

Question 23

What happens in Beta Minus decay in terms of quarks?

Answer 23

A neutron is changed into a proton.
A udd particle changes into a uud particle.
An up quark is formed as a down quark is changed into it,
An electron and anti-electron neutrino is released.

Question 24

What happens in Beta Plus decay, in terms of quarks?

Answer 24

A position is emitted.
A proton changes into a neutron.
A uud particle is changed into a udd particle as an up quark changes into a down quark.
A position and electron-neutrino is released.