Die Erste Stunde (The First Hour)

Diagnosing the Quark-Gluon Plasma

“…The original idea was mainly focused on QGPs produced at the SPS and, possibly, the AGS, because there one expected an abundance of quarks over antiquarks as nuclear matter would be partially stopped. Rafelski pointed out in 1980 that this leads to a suppression of anti-up and anti-down quarks, where anti-strange quarks would not be suppressed and so would be significantly enhanced compared to anti-up and anti-down quarks [2,3]. In a publication [4] he stated the following: "Thus, we almost always have more s than u and d quarks and, in many cases of interest, s/q ≈ 5....…”

Strangeness production in high-multiplicity events

“…Since the early experiments at RHIC and SPS [1][2][3][4][5][6], the production of hadrons containing strange quarks has been used as one of the probes of Quark-Gluon Plasma (QGP) formation, described in the framework of QGP-inspired hydrodynamic models [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The QGP manifests itself in different ways in experimental observables.…”

Hadron modification in a dense baryonic matter

“…At the same time there were no any peculiarities observed in the energetic behaviour of K − /π − ratio. The idea that strangeness is a good signal of deconfinement was put forward by J. Rafelski in 1982 [3]. The argument was the following: it is energetically favourable to produce ss -pairs in deconfined medium than a pairs strange hadrons in hadron gas.…”