Baryons with D5-brane vertex and k-quark states

We study baryons in SU(N) gauge theories, according to the gauge/string correspondence based on IIB string theory. The D5-brane, in which N fundamental strings are dissolved as a color singlet, is introduced as the baryon vertex, and its configurations are studied. We find a point- and split-type of vertex. In the latter case, two cusps appears, and they are connected by a flux composed of dissolved fundamental strings with a definite tension. In both cases, N fundamental quarks are attached on the cusp(s) of the vertex to cancel the surface term. In the confining phase, we find that the quarks in the baryon feel the potential increasing linearly with the distance from the vertex. At finite temperature and in the deconfining phase, we find stable k-quark "baryons", which are constructed of an arbitrary number of k(<N) quarks.