Abstract
A new variational wave function is proposed for the ground state of Bose liquids. It consists of the optimized Jastrow function multiplied to exponentials of three-particle functions. The form of the latter is determined variationally in a formal analysis carried out for the weakly interacting Bose gas. Its appearance implies the summation of a new class of diagrams beginning with fourth-order terms in the interaction strength. Several calculations for realistic systems are proposed.