  We report the first calculation of the simplest but most fundamental
transverse momentum dependent (TMD) distribution of quarks in the nucleon, i.e.
the time-reversal-even unpolarized TMD quark and antiquark distribution with
isoscalar combination, within the framework of the chiral quark soliton model.
The nonperturbative account of the deformed Dirac-sea quarks within the
theoretical scheme enables us to make a reliable predictions not only for the
quark distribution but also for the antiquark distribution. We found that the
predicted average transverse momentum square $<k_\perp^2>$ of quarks and
antiquarks depends strongly on their longitudinal momentum fraction $x$, which
means that the frequently used assumption of factorization in $x$ and $k_\perp$
is significantly violated. It is also found, somewhat unexpectedly, that the
average transverse momentum square of antiquarks is considerably larger than
that of quarks.
