  In this paper, we study the dynamics of an interesting class of vector
solitons in the long wave-short wave resonance interaction (LSRI) system. The
model that we consider here describes the nonlinear interaction of the
long-wave and two-short waves and it generically appears in several physical
settings. To derive this class of nondegenerate vector soliton solutions we
adopt the Hirota bilinear method with the more general form of admissible seed
solutions with nonidentical distinct propagation constants. We express the
resultant fundamental as well as multi-soliton solutions in a compact way using
Gram-determinants. The general fundamental vector soliton solution possesses
several interesting properties. For instance, the double-hump or a single-hump
profile structure including a special flattop profile form results in when the
soliton propagates in all the components with identical velocities.
Interestingly, in the case of nonidentical velocities, the soliton number is
increased to two in the long-wave (LW) component, while a single-humped soliton
propagates in the two short-wave (SW) components. We establish through a
detailed analysis that the nondegenerate multi-solitons in contrast to the
already known vector solitons (with identical wave numbers) can undergo three
types of elastic collision scenarios: (i) shape preserving, (ii) shape
altering, and (iii) a novel shape changing collision, depending on the choice
of the soliton parameters. In addition, we point out the coexistence of
nondegenerate and degenerate solitons simultaneously along with the associated
physical consequences. We also indicate the physical realizations of these
general vector solitons in nonlinear optics, hydrodynamics, and Bose-Einstein
condensates. Our results are generic and they will be useful in these physical
systems and other closely related systems including plasma physics.
