About Quark and Hadronic matter

According to our modern scientific knowledge, our universe is created from a so-called "Big Bang" (which don't have any relation at all with the TV series -"Big Bang Theory" except the scientific motivation for the title....😃... ). From the Big Bang to today, the life time of the universe is approximately 14 billion years (14,👀,👀,👀,👀0 years......). It is expected that the universe is in the state of Quark Gluon Plasma (QGP), just few micro-second after the big bang. RHIC and LHC experiments have recreated this baby universe artificially in the laboratory, which is survived for a very small life time (~10 fm/c ~10^{-22} seconds) within a tiny space (~ 10 fm ). Its evolution picture is as follows.

• Suppose... after Nucleus-Nucleus Collision, at t=0.1 fm, a sufficient energy density can produce QGP..... Now in free space, the plasma will expand and cool down. 

• Suppose... from the initial temperature T_i=400 MeV to near about the transition temperature T_c=170 or160 MeV QGP is converted to hadronic matter, which will expand again and cool down ..... 
• At certain temperature T_f=100 or 120 MeV, all hadrons freeze out from the medium......

The entire story is occurred within the time 10 fm/c and with the space 10 fm (rough volume of expanded medium or fireball)......  After freeze out, these hadrons, who carry this short space-time drama, are coming to the detector by traversing a long monotonic (without any drama) path in space and time, which is approximately 10^15 times larger than volume and life time of the fireball. After detecting them via detector, it is really a challenge for experimentalist, phenomenologist and theoretician to track this 10 fm/c story or drama.