On the K±–meson production from the quark–gluon plasma phase in ultra–relativistic heavy–ion collisions

An abundance of the strangeness that can be induced in a thermalized quark–gluon plasma (QGP) is considered as a signal of the QGP phase appearing in the intermediate state of ultra–relativistic heavy–ion collisions. As a quantitative characteristic of this signal we take the ratio RK+K− = NK+/NK− of the multiplicities of the production of K ± mesons. This ratio is evaluated for a thermalized QGP phase of QCD and for the quark–gluon system escaped from the QGP phase. For a thermalized QGP phase the ratio RK+K− has been found as a smooth function of a 3–momentum of the K mesons and a temperature ranging the values from the region 160MeV < T < 200MeV. We show that at the temperature T = 175MeV our prediction for the ratio RK+K−(q, T = 175) = 1.80 +0.04 −0.18 agrees good with the experimental data of NA49 and NA44 Collaborations on central ultra–relativistic Pb–Pb collisions at 158 GeV per nucleon: R K+K− = 1.80 ± 0.10. For the ratio of the K and π multiplicities we have obtained the value RK+π+(q, T = 175) = 0.134 ± 0.014 agreeing good with the experimental data of NA35 Collaboration on the nucleus–nucleus collisions at 200GeV per nucleon R K+π+ = 0.137± 0.008. PACS numbers: 25.75.–q, 12.38.Mh, 24.85.+p E–mail: [email protected], State Technical University, Department of Nuclear Physics, 195251 St. Petersburg, Russian Federation E–mail: [email protected], Tel.: +43–1–58801–14261, Fax: +43–1–58801–14299 State Technical University, Department of Nuclear Physics, 195251 St. Petersburg, Russian Federation E–mail: [email protected], St.Petersburg Institute for Nuclear Research, Gatchina, Russian Federation Permanent Address: State Technical University, Department of Nuclear Physics, 195251 St. Petersburg, Russian Federation