  We show model wavefunctions for neutral collective modes in fractional
quantum Hall (FQH) states have simple analytic forms obtained from judicially
reducing the powers of selected pairs in the ground state Jastrow factor. This
scheme of "pair excitations" works for the magneto-roton modes of
single-component Abelian and non-Abeliean FQH states, as well as neutral
fermion mode for the Moore-Read (MR) state. The analytic wavefunctions enable
computations in the thermodynamic limit previous inaccessible to numerics, and
the long wavelength limit of the neutral energy gap of the magneto-roton modes
can be interpreted as fusion of charges in two-dimensional plasma picture,
extending the plasma analogy to neutral excitations. A lattice diagrammatic
method of representing these many-body wavefunctions and FQH elementary
excitations is also presented.
