Let's say we solve the Schrodinger equation with infinite well. We can quantize the field by the resonance state and can get the annihilation and creation operator. So we will get the sort of particle corresponding to the resonance state. The resonance state would have mass corresponding to the energy and the mass will exist as the multiple of the minimum energy level.
Is the resonance state a new type of particle? If it's not, what does the creation operator create?
Let's consider we put a photon inside the infinite well. If the photon is not in the resonance state, the photon will be represented by the superposition of the resonance states. So when it goes inside the well, photon seems not a fundamental particle but a complex particle constructed from more basic states.
And if the resonance is the particle, what happens to the photon then? If we put a photon detection device inside the infinite well, can we detect the photon? Or is the photon's identity vanished completely and it's meanless to talk of the photon anymore?