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Flashcards in Quantum Mechanics Deck (45):
1

What is exchanged in the electromagnetic force?

Virtual photons

2

What does the strong force do?

Holds together neutrons and protons in a nucleus

(Holds quarks together)

3

What does the weak force do?

It changes protons to neutrons OR neutrons to protons

(Changes quark flavour)

4

What are the products of ß+ decay?

Positron + neutrino

5

What are the products of ß- decay?

Electron + anti neutrino

6

What exchange particles initiate the weak force?

W+/W- bosons
Z bosons

7

What is a proton made from?

uud (quarks)

8

What is a neutron made from?

udd (quarks)

9

What is a baryon?

Something made of 3 quarks e.g. proton/neutron

10

What is a meson?

Something made of 2 quarks e.g. kaons and pions

11

What is a kaon?

Made of 2 quarks (one quark, one anti quark)

One of the quarks must be strange

12

Order of mass of charged leptons (lightest to heaviest)

Electron
Muon
Tau

13

What are hadrons?

Groups of quarks e.g. baryons and mesons

14

When is strangeness conserved/ not conserved?

CONSERVED: strong/electromagnetic

NOT CONSERVED: weak interaction

15

Charge of up, down and strange quarks:

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

16

What is produced during annihilation?

2 photons

17

What is produced in pair production?

Particle + anti particle

18

When does positron emission happen?

When a proton changes to a neutron in an unstable nucleus with too many protons (a neutrino is also emitted)

19

Particle + corresponding anti particle ------> ...

--> total mass goes to photons
--> have same rest mass
--> equal/opposite charge

20

When does pair production occur?

When a photon with sufficient energy passes a nucleus or an electron, they can suddenly turn into a particle/anti particle pair

21

What is the definition of 1 eV?

1eV is the energy transferred when an electron is moved through a potential difference of 1V

22

1 MeV = ?J

1 MeV = 1.6 x 10^-13 J

23

Equation for Planck's constant:

E=hf



(E = mc^2 = hf)

24

1V = ?

1V = 1 J/C (joule per coulomb)

25

Energy =

Momentum x Velocity

26

How do muons, kaons and pions decay?

Muon - weak force
Kaon - weak force
Pion - strong force

27

Which exchange particle mediates the strong force?

Gluons (also pions)

28

What's the difference between gluons and W bosons?

Gluons = strong force & have greater range
W bosons = weak force

29

Times by what to convert eV to joules?

1.6 x 10^-19

30

Times by what to get MeV to eV?

x 10^6

31

Value of Planck's constant

6.63 x 10^-34

32

In which processes can a proton change to a neutron?

Electron capture

ß+ decay

33

What happens in electron capture?

Proton + electron -----> neutron + neutrino

34

What happens when a neutron and a neutrino interact?

Neutron + neutrino ---> proton + ß-

35

What happens when a proton and anti neutrino interact?

Proton + anti neutrino ----> n + ß+

36

d ś

37

K+

u ś

38

K-

ū s

39

Anti K°

Anti d
S

40

π+

u
Anti d

41

π-

ū d

42

π°

u ū
d anti d

43

What can a kaon decay into?

Pion
Muon + anti neutrino
Anti muon + neutrino

44

What can a pion decay into?

Gamma photon
Muon + anti neutrino
Anti muon + neutrino
Neutrino + anti neutrino

45

What can a muon decay into?

Electron neutrino + anti muon neutrino + positron

Anti electron neutrino + muon neutrino + electron