They are breaking matter down into its elemental particles (quarks, gluons, etc.) then watching it reform into matter again, I guess.
But what matter is being disassembled, and what reforms? Gold is mentioned - is it 21st century alchemy, turning lead into gold, or the opposite, or neither?
Understanding the nature of QGP might give them a better idea of why inflation occurred.
Also, although the microwave background radiation is close to being evenly distributed it is not. This uneven distribution ultimately led to the creation of galaxies and solar systems. However, inflation suggests that the microwave background radiation either should have been perfectly evenly distributed, or at least more evenly distributed than it is. So this is another mystery that understanding the nature of QGP might answer.