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Aim: How can we describe Fundamental Particles?. Four Fundamental forces. 1) Gravitational 2) Electromagnetic 3) Strong Nuclear force 4) Weak Nuclear force. Classification of Matter and Particles of the Standard Model Reference Tables.
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Four Fundamental forces • 1) Gravitational • 2) Electromagnetic • 3) Strong Nuclear force • 4) Weak Nuclear force
Classification of Matter and Particles of the Standard Model Reference Tables • Look at Classification of Matter reference table to see how matter is classified. • Look at Particles of the Standard Model table to go beyond the “dead ends”: quarks and leptons.
Facts to know: • Quarks and leptons are fundamental particles – everything is made of them. • Protons and neutrons are baryrons, composed of three quarks. • Electrons are leptons (very light particles, not made of quarks). • For each particle there is an antiparticle with a charge opposite to its associated particle, and designated with a “bar” over the associated particle.
C. Classification of Subatomic Particles • 1. Hadrons – particles that interact through the strong nuclear force. • Examples: protons, neutrons. • 2. Leptons – particles that do not interact through the strong nuclear force. Have less mass than a proton. • Example: electrons • See reference table
3. Hadrons are divided in to baryons and mesons • a.Baryon – heavy particle; can be transformed into a proton or neutron and some number of lighter particles. • b.Meson – particle of intermediate mass.
4. Antiparticle - • A particle having mass, lifetime and spin identical to the associated particle, but with an opposite charge. • Is denoted with a particle sign with a bar over the sign. • Antimatter is material consisting of atoms composed of antiprotons, antineutrons and positrons.
D. Quarks • 1.Baryons and mesons are composed of quarks • 2.A quark is one of the basic particles • 3.Elementary charges are built up from quarks • 4.Charges on quarks: ±2/3 e, ±1/3 e • 5.Names: up, down, charm, strange, top, bottom
Quarks • 6. Antiquark – antiparticle of a quark, having opposite charge of associated quark. • 7.Baryon – composed of three quarks • a.charges add to (0e, +1e or –1e) • b.proton = uud • c.neutron = udd • 8. Meson – composed of a quark and an antiquark. (charges add to 0e, +1e, or -1e)
Examples: • A proton is composed of what combination of up and down quarks? • 2 up, 1 down (charge: +1) • A neutron is composed of what combination of up and down quarks? • 1 up, 2 down (charge: 0)
How can we classify a particle consisting of an up quark and an anti-down quark? • It’s a meson. • What kind of particle is a muon neutrino? • A lepton. • What is its charge? • 0.
What particles make up an anti-proton? • Anti-up, anti-up, anti-down. • What particles make up a tau neutrino? • None – it is a lepton, a fundamental particle itself.
A particle has a quark composition of sc and classification of the particle.