  We report measurements of the inclusive transverse momentum pT distribution
of centrally produced kshort, kstar(892), and phi(1020) mesons up to pT = 10
GeV/c in minimum-bias events, and kshort and lambda particles up to pT = 20
GeV/c in jets with transverse energy between 25 GeV and 160 GeV in pbar p
collisions. The data were taken with the CDF II detector at the Fermilab
Tevatron at sqrt(s) = 1.96 TeV. We find that as pT increases, the pT slopes of
the three mesons (kshort, kstar, and phi) are similar, and the ratio of lambda
to kshort as a function of pT in minimum-bias events becomes similar to the
fairly constant ratio in jets at pT ~ 5 GeV/c. This suggests that the particles
with pT >~ 5 GeV/c in minimum-bias events are from soft jets, and that the pT
slope of particles in jets is insensitive to light quark flavor (u, d, or s)
and to the number of valence quarks. We also find that for pT <~ 4 GeV
relatively more lambda baryons are produced in minimum-bias events than in
jets.
