Term
D.4.1 State what is meant by an elementary
particle. |
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Definition
| Particles are called elementary if they have no internal structure, that is, they are not made out of smaller constituents. |
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Term
| D.4.2 Identify elementary particles. |
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Definition
| The classes of elementary particles are quarks, leptons and exchange particles. The Higgs particle could be elementary. |
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Term
| D.4.3 Describe particles in terms of mass and various quantum numbers. |
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Definition
| Students must be aware that particles (elementary as well as composite) are specified in terms of their mass and various quantum numbers. They should consider electric charge, spin, strangeness, colour, lepton number and baryon number. |
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Term
| D.4.4 Classify particles according to spin. |
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Definition
Fermions (Leptons and Quarks): 1/2
Bosons: 1 |
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Term
| D.4.5 State what is meant by an antiparticle. |
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Definition
| Has the same mass as its particle but all its quantum numbers are opposite. |
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Term
| D.4.6 State the Pauli exclusion principle. |
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Definition
| No two fermions can occupy the same quantum state. No two fermions in the same quantum system can have the same set of quantum numbers as each other. |
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Term
| D.4.7 List the fundamental interactions. |
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Definition
| gravitational, electroweak (weak and electromagnetic) and strong (fundamental and residual). |
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Term
| D.4.8 Describe the fundamental interactions in terms of exchange particles. |
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Definition
gravitational: graviton (theoretical)
electroweak: W+, W-, Z, photon
strong: gluons, mesons |
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Term
D.4.9 Discuss the uncertainty principle for time and energy in the context of
particle creation. |
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Definition
| A simple discussion is needed in terms of a particle being created with energy ΔE existing no longer than a time Δt given by ΔEΔt ≥ h/4π. |
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Term
D.4.10 Describe what is meant by a Feynman
diagram. |
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Definition
| Feynman diagrams are used to represent possible particle interactions. The diagrams are used to calculate the overall probability of an interaction taking place. |
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Term
D.4.11 Discuss how a Feynman diagram may
be used to calculate probabilities for fundamental processes. |
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Definition
| In calculating probability in quantum mechanics, it's necessary to add together all the possible ways in which an interaction can take place. |
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Term
D.4.12 Describe what is meant by virtual
particles. |
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Definition
| A particle that appears as an intermediate particle in a Feynman diagram. |
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Term
D.4.13 Apply the formula for the range R for interactions involving the exchange
of a particle. |
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Definition
| Applications include Yukawa’s prediction of the pion or determination of the masses of the W ±, Z 0 from knowledge of the range of the weak interaction. |
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Term
D.4.14 Describe pair annihilation and
pair production through Feynman
diagrams. |
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Definition
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Term
D.4.15 Predict particle processes using
Feynman diagrams. |
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Definition
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Term
| D.5.1 List the six types of quark. |
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Definition
| up, down, charm, strange, top, bottom |
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Term
| D.5.2 State the content, in terms of quarks and antiquarks, of hadrons (that is, baryons and mesons). |
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Definition
E.g.
proton: uud
antiproton: anti-u anti-u anti-d
neutron: udd
lambda: uds
omega: sss
pion: u anti-d
kaon: s anti-u
rho: u anti-d
B-zero: d anti-b
eta-c: c anti-c |
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Term
| D.5.3 State the quark content of the proton and the neutron. |
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Definition
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Term
D.5.4 Define baryon number and apply
the law of conservation of baryon number. |
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Definition
baryons have baryon number +1,
antibaryons have baryon number -1. In all interactions, baryon number is always conserved. |
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Term
D.5.5 Deduce the spin structure of hadrons
(that is, baryons and mesons). |
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Definition
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Term
| D.5.6 Explain the need for colour in forming bound states of quarks. |
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Definition
| Students should realize that colour is necessary to satisfy the Pauli exclusion principle. The fact that hadrons have no colour is a consequence of confinement. |
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Term
| D.5.7 State the colour of quarks and gluons. |
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Definition
| quarks can be red, yellow, or blue. Gluons have eight types. |
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Term
| D.5.8 Outline the concept of strangeness. |
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Definition
It is sufficient for students to know that the strangeness of a hadron is the number of anti‑strange quarks minus the number of strange quarks it contains.
Students must be aware that strangeness is conserved in strong and electromagnetic interactions, but not always in weak interactions. |
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Term
| D.5.9 Discuss quark confinement. |
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Definition
| Students should know that isolated quarks and gluons (that is, particles with colour) cannot be observed. The strong (colour) interaction increases with separation. More hadrons are produced when sufficient energy is supplied to a hadron in order to isolate a quark. |
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Term
D.5.10 Discuss the interaction that binds nucleons in terms of the colour force
between quarks. |
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Definition
| It is sufficient to know that the interaction between nucleons is the residual interaction between the quarks in the nucleons and that this is a short-range interaction. |
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Term
D.1.1 Describe what is meant by a frame of
reference. |
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Definition
| A three-dimensional coordinate system. |
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Term
D.1.2 Describe what is meant by a Galilean
transformation. |
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Definition
| Using measurements in one frame of reference to work out the measurements that would be recorded in another frame of reference. |
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Term
| D.1.3 Solve problems involving relative velocities using the Galilean transformation equations. |
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Definition
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Term
| D.2.1 Describe what is meant by an inertial frame of reference. |
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Definition
| A frame of reference in which Newton's laws apply. The observer is not accelerating. |
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Term
| D.2.2 State the two postulates of the special theory of relativity. |
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Definition
The speed of light in a vacuum is constant for all inertial observers.
Laws of physics are the same for all inertial observers. |
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Term
| D.2.3 Discuss the concept of simultaneity. |
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Definition
| Students should know that two events occurring at different points in space and which are simultaneous for one observer cannot be simultaneous for another observer in a different frame of reference. Similarly, simultaneous events taking place in the same point in space are simultaneous for all observers. |
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Term
| D.3.1 Describe the concept of a light clock. |
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Definition
| An imaginary device that measures time using the speed of light. |
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Term
| D.3.2 Define proper time interval. |
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Definition
| the time measured in a frame of reference stationary with the measured event. |
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Term
| D.3.2 Define proper time interval. |
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Definition
| Oh god. This won't go well. |
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Term
| D.3.4 Sketch and annotate a graph showing the variation with relative velocity of the Lorentz factor. |
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Definition
| Can't be bothered to go add the picture. Lorentz factor increases drastically when nearing speed of light, c being a vertical asymptote. |
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Term
D.3.5 Solve problems involving time
dilation. |
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Definition
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Term
| D.3.6 Define proper length. |
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Definition
| length as measured stationary with the object. |
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Term
D.3.7 Describe the phenomenon of length
contraction. |
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Definition
| According to a stationary observer, the separation between two points in space contracts in the direction of the relative motion. |
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Term
D.3.8 Solve problems involving length
contraction. |
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Definition
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