- 2. Particles have a wavefunction (Y) = (3.0 + 1.2i)|a) + (1.2 1.2i)|), which includes the spin up eigenfunction, (a), and the spin down eigenfunction, B). a. (3 pts) If an experimentalist measures the spin of 2500 particles, how many spin up particles could he or she expect? b. (2 pts) The following operators give the z-axis component of the spin angular momentum. With the same wavefunction, what is the expectation value of the z-axis component of the spin angular momentum operator, >? (a) = 21a) - h 2 IB)