  The chiral symmetry breaking in the presence of an external magnetic field is
studied in the framework of logarithmic quark-sigma model with three flavors
(u,d,s). The effective logarithmic mesonic potential is extended to strange
quark and is numerically solved in the mean-field approximation. The present
results show that the chiral symmetry breaking is sensitive for the strange
quark flavour in the presence an external magnetic field. In addition, the
effect of the free parameters is studied. A comparison with original sigma
model is discussed.
