A free quark

From wiki, quark:

"A state of entirely free
quarks and gluons has never
been achieved (despite numerous
attempts by CERN in the 1980s and 1990s) [83]"

U. Heinz, M. Jacob (2000). "Evidence for a New State of Matter: An Assessment of the Results from the CERN Lead Beam Programme". arXiv:nucl-th/0002042 [nucl-th].

"Present theoretical ideas provide a more
precise picture for this new state of matter: it should be a quark-gluon plasma
(QGP), in which quarks and gluons, the fundamental constituents of matter, are
no longer confined within the dimensions of the nucleon, but

FREE TO MOVE AROUND

over a volume in which a high enough temperature and/or density prevails."

"It has been expected that in high energy collisions between heavy nuclei sufficiently
high energy densities could be reached such that this new state of matter
would be formed. Quarks and gluons would then

FREELY ROAM within the volume of
the fireball created by the collision."

---

"Hadrons are strongly interacting particles. In nuclear collisions, after being first
created, they undergo many secondary interactions before escaping from the collision
“fireball”. When they are finally

SET FREE,

the fireball volume has expanded by about
a factor 30–50."

----