Quarks and Leptons Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are cosmic rays?

A

High energy particles that travel through space from the stars. including the sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do cosmic rays do?

A

They collide with gas atoms in the atmosphere, creating showers of particles and antiparticles which can be detected at ground level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does a kaon decay into?

A

Pions, or muon and antineutrino, or antimuon and neutrino.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does a charged pion decay into?

A

A muon and an antineutrino, or antimuon and neutrino.π 0 meson decays into high energy photons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a muon, and what does it decay into?

A

It is a heavy electron, it decays into an electron and an anitneutrino and an muon neutrino.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are kaons produced?

A

They’re produced in two’s through the strong interaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do kaons decay?

A

They decay through the weak interaction. These properties lead them to being called strange particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are hadrons?

A

Particles/antiparticles that interact through the strong force - E.G - protons, neutrons, pi mesons and k mesons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are leptons?

A

Particles/antiparticles which don’t interact through the strong interaction. E.G: electrons, muons and neutrinos.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do leptons interact through?

A

mostly the weak interaction but also a bit through the gravitational interaction and electromagnetic interaction if charged.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can hadrons interact through?

A

All four fundamental interactions. They interact through the electromagnetic interaction if charged.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Apart from hadrons, which is stable, what do hadrons tend to decay through?

A

The weak interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are baryons?

A

Protons and all other hadrons that decay into protons, either directly or indirectly. They are made up of 3 quarks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are mesons?

A

Hadrons that don’t include protons in their decay products. So kaons and pions aren’t baryons. Made up of quark antiquark.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do leptons produce when they interact?

A

Hadrons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name some leptons

A

electron, muon, neutrino and corresponding antiparticles.

17
Q

In an interaction between a lepton and a hadron, what changes into what?

A

A neutron/neutrino can change into a lepton.

18
Q

What happens in muon decay?

A

A muon changes into a muon neutrino, and an electron is created to conserve charge. A corresponding antineutrino is created to conserve lepton number.

19
Q

What do strange particles decay through?

A

The weak interaction.

20
Q

When is strangeness always conserved? When can it change?

A

During the strong interaction it is always conserved. In the weak interaction it can change by 0, +1 or -1.

21
Q

What is the quark combination for a meson?

A

Quark, antiquark. π0 meson can be any quark - corresponding antiquark combination.

22
Q

What is the quark composition for baryons and antibaryons?

A

Three quarks for a baryon and three anti quarks for an antibaryon.

23
Q

What is the quark composition for a proton?

A

uud

24
Q

What is quark composition for a neutron?

A

udd

25
Q

What is the quark change in beta minus decay and beta plus decay?

A

Beta minus: down turns into an up quark.

beta plus: Up turns into a down quark.

26
Q

What is always conserved in particle interactions?

A

Energy, charge, lepton number, baryon number.

27
Q

what values are assigned for leptons, baryons and strange particles

A

Leptons - +1, anti leptons - (-1)
Baryons - +1, antibaryons - (-1)
Strange particle - (-1), anti strange particle - (+1)

28
Q

What are leptons?

A

They are fundamental particles that don’t interact through the strong force.