Particles

Question 1

Pair production and requirements

Answer 1

Energy is converted into a particle and its antiparticle. The photon’s energy needs to provide at least the rest masses of the particles.

Question 2

Describe annihilation.

Answer 2

A particle and it’s antiparticle meet and annihilate and their masses are converted into energy in the form of two photons.

Question 3

Compare the mesons pions and kaons

Answer 3

Pions are the lightest. Kaons are heavier and more unstable, they have strangeness and decay into pions.

Question 4

Describe electron capture.

Answer 4

The nucleus captures an orbital electron, changing the p and e- into a neutron and electron neutrino.

Question 5

What is conserved in particle interactions?

Answer 5

Energy
Momentum
Charge
Baryon number
Lepton number
Strangeness (but not in weak interactions)

Question 6

Name 3 fundamental forces and their exchange particle

Answer 6

Weak nuclear force - w boson
Strong force - pions
Electromagnetic - photons