11.5 The Standard Model

Interactions as exchange-particle vertices drawn in Feynman diagrams, force range set by the uncertainty principle, and the reach for grand unification.

University Physics Volume 3, 11.5 The Standard Model

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6 exercises

11.5 Exercise 1

What is the Standard Model? Express your answer in terms of the four fundamental forces and exchange particles.

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11.5 Exercise 3

What is the motivation behind grand unification theories?

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11.5 Exercise 5

If the Higgs boson is discovered and found to have mass, will it be considered the ultimate carrier of the weak force? Explain your response.

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11.5 Exercise 8

Use the Heisenberg uncertainly principle to estimate the range of a weak nuclear decay involving a graviton.

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11.5 Exercise 10

Assuming conservation of momentum, what is the energy of each $\gamma$ ray produced in the decay of a neutral pion at rest, in the reaction $\pi^{0} \rightarrow \gamma + \gamma$ ?

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11.5 Exercise 12

The primary decay mode for the negative pion is $\pi^{−} \rightarrow \mu^{−} + \left(\overset{−}{\nu}\right)_{\mu} .$ (a) What is the energy release in MeV in this decay? (b) Using conservation of momentum, how much energy does each of the decay products receive, given the $\pi^{−}$ is at rest when it decays? You may assume the muon antineutrino is massless and has momentum $p = E / c$ , just like a photon.

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