The isospin strange asymmetry from the chiral effective theory.

The proposal of the present work is to study the difference between the strange quark–antiquark amount in the proton and neutron. For this purpose, the possible nucleon–hyperon–kaon fluctuations are analyzed with the effective chiral theory. The small difference of particle masses is shown to be in the origin of this isospin asymmetry. The dependence of the results on the mass cutoff parameter and with the coupling constants is analyzed. [ABSTRACT FROM AUTHOR]