Equation of state of hadronic matter with dibaryons in an effective quark model

The equation of state of symmetric nuclear matter with the inclusion of non strange dibaryons is studied. We pay special attention to the existence of a dibaryon condensate at zero temperature. These calculations have been pe rformed in an extended quark-meson coupling model with density-dependent pa rameters, which takes into account the finite size of nucleons and dibaryon s. A first-order phase-transition to pure dibaryon matter has been found. T hr corresponding critical density is strongly dependent on the value of the dibaryon mass. The density behavior of the nucleon and dibaryon effective masses and confining volumes have been discussed. (C) 1999 Elsevier Science B.V. All rights reserved.