No abstract

We derive the trapping energy of a colloidal particle at a liquid interface with contact angle θ and principal curvatures c1 and c2. The boundary conditions at the particle surface are significantly simplified by introducing the shift ε of its vertical position. We discuss the undulating contact line and the curvature-induced lateral forces for a single particle and a pair of nearby particles. The single-particle trapping energy is found to decrease with the square of both the total curvature c1 + c2 and the anisotropy c1 − c2. In the case of non-uniform curvatures, the resulting lateral force pushes particles toward more strongly curved regions.

In the framework of a pure chromomagnetic Hamiltonian, we study all the states of gq4 systems allowed by the Pauli principle. The wave functions are analyzed by group-theoretical techniques in a first step where the antiquark has an infinite mass and the quarks belong to an SU(3)F multiplet. The breaking of these symmetries is performed exactly through two parameters 17 and 6. The emphasis is put on the corresponding energies relative to the physical thresholds in gq + q 3 . We propose a number of new multiquarks which could be stable under strong interactions.