Relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained. The five-quark amplitudes for the low-lying pentaquarks are calculated under the condition that flavor SU(3) symmetry holds. The poles of the five-quark amplitudes determine the masses of the lowest pentaquarks. The mass spectra of pentaquarks which contain only light quarks are calculated. The calculation of pentaquark amplitudes estimates the contributions of three subamplitudes: molecular subamplitude BM, Mqqq subamplitude and [Formula: see text] subamplitude. The main contributions to the pentaquark amplitude are determined by the subamplitudes, which include the meson states M.
Mass spectra of doubly heavy baryons in the relativistic quark model
