spins_unit_schrodinger_time_evolution.ppt Pages 36-42

• (this simple introduction is based on a 2-state system, no tau neutrino is used in the calculations)
• 15 minute introduction to what neutrinos are, the current interest in understanding how much mass they have, and why they have mass, evidence for neutrinos changing flavor before between leaving the sun and reaching the earth, measurements made at Super-K, Weak vs. free state Hamiltonian
• Define a basis state for the neutrinos according to the Weak Hamiltonian and according to the free state Hamiltonian. Explain how we know they're not the same, based on the fact the two Hamiltonians do not commute
• Activity: have students write the weak basis in terms of the free state basis as an extension of our 2-level system knowledge. Then have them write these as time evolved states under the free space Hamiltonian
• Simplify the energy eigenvalues of the free space Hamiltonian so the time expansion can be written more simply, and have students calculate the probability for finding a muon starting with one flavor and ending with another
• Expose students to Super-K and current data
• Discuss current puzzle as to why neutrinos have mass, and why our current models can't account for it
• I briefly introduced the CKM matrix and quark mixing since it is involved with CP violation and the 2008 Nobel prize, but was probably

a bit beyond what our students were ready to hear, having no exposure to particle physics at this stage