Particles And Nuclear Structure Flashcards
What are examples of leptons? And what are their charges?
Electrons (-1) and electron neutrino (0)
What are examples of quarks? And what are their charges?
Up (+2/3) and Down (-1/3) quarks
What happens when a particle meets an anti particle?
They annihilate each other. This means when a particle encounters its antiparticle (e.g. an electron and a positron), all the mass is converted into energy.
What are examples of anti-leptons? What are their charges?
Positron (+1) and electron antineutrino (0)
What are examples of anti-quarks? What are their charges?
Antiup (-2/3) and antidown (+1/3)
What are the lepton numbers of leptons and anti leptons?
Electrons and electron neutrinos have a lepton number of 1. Their antiparticles, positrons and electron antineutrinos have a lepton number of -1.
Properties of a proton?
Charge: +1
Baryon #: 1
Composition: uud
Properties of a neutron?
Charge: 0
Baryon #: 1
Composition: udd
4 ways to make pions? State the charges?
π- is ūd (-1e)
π+ is uď (+1e)
π• is uū (0e)
π• is also dď (0e)
What are leptons?
The lightest subatomic particles that always exist separately and do not form composite particles.
Do quarks exist separately?
No, quarks and antiquarks combine to form hadrons.
What are the three types of hadrons?
- Baryons – Consist of 3 quarks.
- Antibaryons – Consist of 3 antiquarks.
- Mesons – Consist of 1 quark-antiquark pair.
What is the baryon number of a quark and an antiquark?
• Quark: +⅓
• Antiquark: -⅓
What are the baryon numbers of baryons and antibaryons?
• Baryons: +1
• Antibaryons: -1
What are the four fundamental forces?
- Gravitational
- Weak Nuclear
- Electromagnetic (E-M)
- Strong Nuclear
What are the key characteristics of the gravitational force?
• Experienced by all matter.
• Infinite range.
• Very weak—negligible except for large objects like planets.
What are the key characteristics of the weak nuclear force?
• Acts on all leptons and quarks.
• Very short range.
• Significant only when electromagnetic and strong interactions do not operate.
What are the key characteristics of the electromagnetic force?
• Acts on all charged particles.
• Infinite range.
• Experienced by neutral hadrons, as they are made of quarks.
What are the key characteristics of the strong nuclear force?
• Experienced by all quarks.
• Short range.
What are the characteristics of strong interactions?
• Only hadrons are involved.
• No change in quark flavor.
• Involved in particle collisions.
• Lifetime: ~10⁻²⁴ s.
What are the characteristics of electromagnetic interactions?
• Particles must be charged or have charged components.
• No change in quark flavor.
• One or more photons may be emitted.
• Lifetime: ~10⁻¹² to 10⁻¹⁸ s.
What are the characteristics of weak interactions?
• Involves neutral leptons (neutrinos).
• Quark flavor may change.
• Lifetime: ~10⁻⁸ s.
