[inlineint]

The standard model provides a set of postulates that could be used for prediction of possible composite particles, their masses, and decay times.

However it is computationally infeasible to calculate them directly, without using various approximations. Physicists try to solve these problems numerically (see for example about the field called lattice QCD), but it is not always possible and leads to introducing various approximations that produce errors and other artifacts in the numerical predictions.

So the particles were allowed by the standard model, but we didn't know for sure their properties. So this provides way to verify already done numerical predictions (I don't really know were they be done for this exact particles or not) and give us data about exact properties of these particles.

One could possibly draw an analogy with (quantum) chemistry here.