This is the '''probability''' of observing the particle between points ''a'' and ''b''. For some wavefunctions, such as that of a free particle, the integral above does not exist and so they are said to be non-normalisable. | This is the '''probability''' of observing the particle between points ''a'' and ''b''. For some wavefunctions, such as that of a free particle, the integral above does not exist and so they are said to be non-normalisable. |