\\
Title:
Authors: H. Kleinert and A.M. Chervyakov
\\
Abstract:
QCD strings are color-electric flux tubes between quarks
with a finite thickness
and thus a finite
curvature stiffness. Contrary to an earlier
rigid-string
by Polyakov and Kleinert 
and motivated by the properties of a magnetic flux tubes
in type-II superconductors we
put forward the hypothesis that
QCD strings have a {\em negative\/ stiffness.
We set up a new string
model with this property and show that it is free of
the three principal problems of
rigid-strings --- particle states with negative norm,
nonexistence of a lowest-energy state, and wrong
high-temperature behavior of string tension ---
thus making it a better candidate for a string
description of quark forces than previous models.
\\