Particle And Nuclear Phsyics Flashcards Preview

AQA A level Physics > Particle And Nuclear Phsyics > Flashcards

Flashcards in Particle And Nuclear Phsyics Deck (47)
Loading flashcards...
1
Q

State quark composition of Baryon

A

qqq

2
Q

What is the quark composition of a K - meson

A

Ūs

3
Q

What is the equation of electron capture

A

P+e-~n+Ve

4
Q

Quark structure of K^0

A

D š

5
Q

Quark structure of proton

A

uud

6
Q

Quark structure of neutron

A

udd

7
Q

Charge of pion +

A

+1

8
Q

What is a sigma+ particle and what’s its charge and number

A

Baryon with Baryon number +1 and charge +1

9
Q

Give one property of an antiparticle that is same for its corresponding particle and one difference

A

Same rest mass energy

Different charge

10
Q

Name two baryons

A

Proton

Neutron

11
Q

State one characteristic of a strange particle that makes it different from a particle that is not strange

A

Has a strange quark

12
Q

Give one difference between negative muon and an electron

A
Different rest mass 
Same charge (negative )
13
Q

Give a difference between hadron and leptons

A

Leptons do not feel strong force

14
Q

What are the differences between mesons and baryons

A

Baryons made from 3 quarks whereas mesons is a quark antiquark pair
Baryon number is +1/-1 mesons is 0

15
Q

What property defines a hadron

A

Feels the strong force

16
Q

What is the exchange particle in the strong, weak and electromagnetic force

A

Electromagnetic- photon
Strong force - gluon
Weak force - w+/w-

17
Q

What is an isotope

A

Forms of the same element that have the same number of protons but a different number of neutrons

18
Q

What is the nature of an alpha particle

A

2 protons , 2 neutrons

19
Q

What is the sigma + particle and what does it contain

A

It is a baryon with 3 quarks which is affected by the weak force and will eventually decay into a proton

20
Q

Name a force that acts between the up quark and an electron . How does this operate

A

The weak force uses a W+/- exchange particle to transfer energy . This then leads to the creation of a new particle .

21
Q

Explain why two photons are formed instead of a single photon when helium nucleus annihilates with an anti helium nucleus

A

Momentum is conserved

So need two photons travelling in different directions

22
Q

What is decay of a neutron equation

A

N~p+e-+Ve with hat

23
Q

What is meant by specific charge

A

Ratio of charge to mass of nucleus

Measured in Ckg-1

24
Q

Lepton number of electron and positron

A

e- = 1 e+=-1

25
Q

Lepton number of ve with hat

A

-1

26
Q

Charge of ve and ve with hat

A

Ve = +1

Ve with hat = -1

27
Q

What is the k0 and how does it decay

A

It is a meson with a strange quark so decays with the weak interaction

28
Q

Which constituent of an atom has the largest specific charge

A

Electron

29
Q

Why is there a minimum energy of the y photon for this conversion to take place in Pair production
What will happen if y photon has slightly more energy

A

To provide enough energy for the rest mass

Any extra energy will provide the particles with extra kinetic energy

30
Q

What is the quark structure of anti K0 meson

A

D with hat s

31
Q

Pion + quark structure

A

U D with hat

32
Q

Pion- quark structure

A

D U with hat

33
Q

Pion 0 quark structure

A

Uū or dd with hat

34
Q

Kaon + quark structure

A

35
Q

Sigma - and sigma 0 strangeness

A

-1

36
Q

What can the kaon decay into

A

Pions

37
Q

What is fundamental about the photon

A

No charge

Massless

38
Q

What is meant by electron capture

A

An atomic electron that interacts with a proton in the nucleus via the weak interaction

39
Q

What is equation for k- meson decay

A

K-~ pi0+e-+v with hat

40
Q

What is the difference between B+ and B- decay

A

In beta+ decay, a proton in the nucleus becomes a neutron and spits out a positron and a neutrino.

In beta- decay, a neutron in the nucleus becomes a proton, and spits out an electron and an anti-neutrino.

41
Q

How does the nucleon and proton number change in Alpha decay

A

nucleon- -4

proton- -2

42
Q

How does the nucleon and proton number change in Beta decay

A

nucleon- 0

proton- +1

43
Q

Describe how the strong nuclear force and two nucleons varies with separation of the nucleons quoting suitable values for seperation

A

repulsive from 0-0.5fm
attractive from 3fm
Repulsive after that

44
Q

What will likely happen to a positron shortly after its emission during pair production

A

Meets and electron and annihilates to produce two more photons

45
Q

What particle is produced when a muon decays

A

Electron + an electron antineutrino + muon neutrino

46
Q

What happens when a particle meets its corresponding anti-particle

A

They annihilate each other

This means that the total mass of the particle is converted into energy, in the form of two gamma ray photons

Two gamma photons are always produced during particle-antiparticle annihilation in order to conserve momentum

47
Q

What occurs in pair production

A

Opposite to annihilation

In this process, a photon with enough energy can interact with a large nucleus and be converted into a particle-antiparticle pair

In order to create this particle-antiparticle pair, the photon must have enough energy to create both particles