Exam 28: Particle Physics

An alternate statement of the uncertainty principle involves relationship between position $\Delta$ x) and momentum $\Delta$ p) uncertainties in the form . Suppose that a 40-kg runner in an imaginary world in which Planck's constant has the value 100 J • s must be located at the finish line to an accuracy of ± 0.33 m to be sure that she won the race. What would be the minimal uncertainty in the speed in that world?

Conservation laws that describe events involving the elementary particles include the conservation of

Current thought is that all matter is composed of

The reaction $\mu$ ^- ? e^- + + conserves

Which of the following statements about antiparticles is true?

Which of the following are possible combinations of quarks? 1) 2) 3) 4) 5) 6)

The interaction that describes the forces among nucleons that hold nuclei together is

The charge of the particle is

The charge of the particle with a quark composition of uss is

An electron with kinetic energy 589 keV collides with a positron of the same kinetic energy moving in the opposite direction. Calculate the wavelength of the two identical photons produced in the annihilation.

Leptons

The field quanta associated with the strong force between quarks are called

The fact that the reaction ³⁷Cl + → ³⁷Ar + e^- is not observed whereas the reaction p + → n + e⁺ is observed is understandable in terms of the conservation of

Particles that participate in the strong nuclear interaction are called

In the standard model, weak charge is

In the standard model, as with the leptons, there are 3 generations of quarks u&d, c&s, and t&b). The reason for this is

According to Hubble's law, the age of the universe is

The field quanta that are thought to be mediating the gravitational force is called

Particles that decay via the strong interaction have lifetimes of the order of

The charge of the u quark is