Consider the 2-slit experiment of the Aharonov-Bohm e ect. Assume that the magnetic eld is con ned to a very small region so the probability of any parti- cle actually entering the region with non-zero magnetic eld is negligible. The solenoid creating the magnetic eld is placed midway between the two slits. Calculate the interference pattern as the function of the magnetic ux B di- rectly across this midway point, i.e. where the interference pattern is maximal when no magnetic eld is present. Take the amplitude in the B = 0 case as a known value, and relate the B 6= 0 interference to it. Make a sketch showing the intensity at the midway point vs the magnetic ux. What magnetic ux is needed to observe at least 2 minima