  In the symmetric string fragmentation recipe adopted by PYTHIA for jet
simulations, the transverse momenta of successive quarks are uncorrelated. This
is a simplification but has no theoretical reason. Transverse momentum
correlations are naturally expected, for instance, in a covariant
multiperipheral model of quark hadronization. We propose a simple recipe of
string fragmentation which lead to such correlations. The definition of the jet
axis and its relation with the primordial transverse momentum of the quark is
also discussed.
