Particle Physics

Question 1

What are atoms made up of?

Answer 1

Atoms are made up of electrons, neutrons and protons. Electrons are first generation leptons with protons and neutrons being combinations of first generation quarks

Question 2

Explain the first two generation leptons and the law of nature

Answer 2

The two first generation leptons are the electron (e’) and the electron neutrino (➰e). The law of nature says that lepton numbers are conserved so first generation leptons numbers are the same before and after any interaction

Question 3

Explain the two first generation quarks

Answer 3

The two first generation quarks are the up-quark
(u, charge 2/3e), and the down-quark (d, charge -1/3e). The u and d are referred to as two flavours of quark. Quarks and antiquarks cannot be isolated, however can be found in combinations called hadrons.

Question 4

What are the 3 types of hadrons?

Answer 4

• Mesons
• Baryons
• Anti-Baryons

Question 5

What are mesons?

Answer 5

Mesons are quark-antiquark pairs called pions. The 🎵+ (ud’), the 🎵- (u’d) and the 🎵* (uu’ or dd’)

Question 6

What are baryons?

Answer 6

Baryons are combinations of 3 quarks. There is the proton (uud) and the neutron (udd)

Question 7

What are anti-baryons?

Answer 7

Anti-baryons are combinations of 3 anti-quarks. There is the anti-proton (u’u’d’) and the anti-neutron (u’d’d’)

Question 8

What’s the conservation of momentum?

Answer 8

In a particle interaction, total momentum stays constants

Question 9

Conservation of mass-energy

Answer 9

In a particle interaction, mass-energy is never created or destroyed

Question 10

Conservation of charge and example

Answer 10

In a particle interaction, total charge stays constant

udd. = neutron
= 0
(2/3e)(-1/3e)(-1/3e). = 0

Question 11

Conservation of lepton number and example

Answer 11

In a particle interaction, total lepton number stays constant

Ve + H2-1 ➡️ P + P + e-
(1) + (0) ➡️ (0)+(0)+(1)

Question 12

Conservation of baryon number/quark number

Answer 12

In a particle interaction, total baryon number stays constant

4u’s ➡️ 4u’s
2d’s ➡️ 2d’s

Question 13

What do strong forces have?

Answer 13

Rearrangement of quarks into different hadrons

No change in quark flavour

Question 14

What do weak forces have?

Answer 14

Change in quark flavour

Electron neutrino involved

Question 15

What do electromagnetic forces have?

Answer 15

Charged particles

Photon emission