  The symmetry breakdown pattern is studied in models containing one fermion
flavor multiplet and a multicomponent scalar field, supplemented with a chiral
Yukawa-interaction, and in presence of an explicit symmetry breaking source
quadratic in the scalar field. In a detailed investigation of the model with
$U_L(1) \times U_R(1)$ chiral symmetry it is shown that by diminishing the
strength of quadratic explicit symmetry breaking one can still keep stable the
mass ratio of the fermionic and the pseudo-Goldstone excitation. At the same
time the mass ratio of the two bosonic excitations appears to approach a
limiting value depending only on the infrared value of the first ratio, but not
on the microscopic (ultraviolet) coupling values. The observations receive a
general interpretation by the existence of an ultraviolet fixed point located
in the symmetric phase. Understanding the general conditions for its existence
allows the construction of a similar theory with $U_L(2) \times U_R(2)$ chiral
symmetry. All results of the present investigation were obtained with
nonperturbative functional renormalisation group technique making use of the
first two approximations to the gradient expansion of the effective action.
