Strange meson production in Al+Al collisions at 1.9A GeV

The production of K$^+$, K$^-$ and $\varphi$(1020) mesons is studied in Al+Al collisions at a beam energy of 1.9A GeV which is close or below the production threshold in NN reactions. Inverse slopes, anisotropy parameters, and total emission yields of K$^{\pm}$ mesons are obtained. A comparison of the ratio of kinetic energy distributions of K$^-$ and K$^+$ mesons to the HSD transport model calculations suggests that the inclusion of the in-medium modifications of kaon properties is necessary to reproduce the ratio. The inverse slope and total yield of $\phi$ mesons are deduced. The contribution to K$^-$ production from $\phi$ meson decays is found to be [17 $\pm$ 3 (stat) $^{+2}_{-7}$ (syst)] %. The results are in line with previous K$^{\pm}$ and $\phi$ data obtained for different colliding systems at similar incident beam energies.Comment: 16 pages, 11 figure

Centrality dependence of subthreshold ϕ\phi meson production in Ni+Ni collisions at 1.9A GeV

We analysed the $\phi$ meson production in central Ni+Ni collisions at the beam kinetic energy of 1.93A GeV with the FOPI spectrometer and found the production probability per event of $[8.6 ~\pm~ 1.6 ~(\text{stat}) \pm 1.5 ~(\text{syst})] \times 10^{-4}$. This new data point allows for the first time to inspect the centrality dependence of the subthreshold $\phi$ meson production in heavy-ion collisions. The rise of $\phi$ meson multiplicity per event with mean number of participants can be parameterized by the power function with exponent $\alpha = 1.8 \pm 0.6$. The ratio of $\phi$ to $\text{K}^-$ production yields seems not to depend within the experimental uncertainties on the collision centrality, and the average of measured values was found to be $0.36 \pm 0.05$.Comment: 9 pages, 5 figure

Systematics of pion emission in heavy ion collisions in the 1A GeV regime

Using the large acceptance apparatus FOPI, we study pion emission in the reactions (energies in GeV/nucleon are given in parentheses): 40Ca+40Ca (0.4, 0.6, 0.8, 1.0, 1.5, 1.93), 96Ru+96Ru (0.4, 1.0, 1.5), 96Zr+96Zr (0.4, 1.0, 1.5), 197Au+197Au (0.4, 0.6, 0.8, 1.0, 1.2, 1.5). The observables include longitudinal and transverse rapidity distributions and stopping, polar anisotropies, pion multiplicities, transverse momentum spectra, ratios for positively and negatively charged pions of average transverse momenta and of yields, directed flow, elliptic flow. The data are compared to earlier data where possible and to transport model simulations.Comment: 56 pages,42 figures; to be published in Nuclear Physics

Influence of ϕ\phi mesons on negative kaons in Ni+Ni collisions at 1.91A GeV beam energy

$\phi$ and K$^-$ mesons from Ni+Ni collisions at the beam energy of 1.91A GeV have been measured by the FOPI spectrometer, with a trigger selecting central and semi-central events amounting to 51% of the total cross section. The phase space distributions, and the total yield of K$^-$, as well as the kinetic energy distribution and the total yield of $\phi$ mesons are presented. The $\phi$\K$^-$ ratio is found to be $0.44 \pm 0.07(\text{stat}) ^{+0.18}_{-0.12} (\text{syst})$, meaning that about 22% of K$^-$ mesons originate from the decays of $\phi$ mesons, occurring mostly in vacuum. The inverse slopes of direct kaons are up to about 15 MeV larger than the ones extracted within the one-source model, signalling that a considerable share of gap between the slopes of K$^+$ and K$^-$ could be explained by the contribution of $\phi$ mesons to negative kaons.Comment: 8 pages, 6 figure

The verification of the zinc-lead resources of the Zawiercie I, Zawiercie II, Gołuchowice and Marciszów deposits (Silesian-Cracow Triassic Province)

Zasoby bilansowe złóż: Zawiercie I, Zawiercie II, Gołuchowice i Marciszów wynoszą obecnie ok. 50 mln Mg rudy zawierającej ok. 2,2 mln Mg cynku i ok. 0,8 mln Mg ołowiu. Do obliczeń zasobów wykorzystano archiwalne wyniki prac dokumentacyjnych, aktualne kryteria bilansowości oraz nową metodykę, tzw. promienia autokorelacji. Rudy siarczkowe Zn–Pb występują głównie w okruszcowanych utworach triasu środkowego określanych jako dolomity kruszconośne, obejmujące warstwy gogolińskie i górażdżańskie. Największe udokumentowane geologiczne zasoby bilansowe (w kat. C1 + C2) występują w złożach: Gołuchowice (ok. 28 mln Mg rudy Zn–Pb, w tym ok. 0,95 mln Mg Zn i 0,23 mln Mg Pb) i Zawiercie I (ok. 17 mln Mg rudy Zn–Pb, w tym ok. 1 mln Mg Zn i 0,4 mln Mg Pb). W złożach Zawiercie II i Marciszów zasoby rud oraz obszary złożowe uległy, w stosunku do wcześniejszych wyliczeń opartych na dawnych kryteriach i innej metodyce (tzw. wieloboków Bołdyriewa), znacznemu zmniejszeniu, głównie ze względu na zbyt słabe rozpoznanie siatką wierceń (kat. C2 + D). Obecne, zasoby niezagospodarowanych czterech złóż rejonu zawierciańskiego stanowią ok. 52,4% całkowitych zasobów rud Zn–Pb regionu śląsko-krakowskiego. Złoże Zn–Pb Gołuchowice po skreśleniu z Bilansu zasobów kopalin i wód podziemnych w 1993 r., w wyniku przeprowadzonej weryfikacji zasobów, zostało przywrócone do Bilansu w 2009 r. (wg stanu na 31.12.2008 r.).The total indicated mineral resources calculated for the Zn–Pb deposits of Zawiercie I, Zawiercie II, Gołuchowice and Marciszów are ca. 50 millionMgof sulphide ores containing ca. 2.2 millionMgof zinc and ca. 0.8 millionMgof lead. Recalculation of the resources was based on archive data collected in the second half of the 20th century, current balance criteria, and a new method called radius of autocorrelation. Zinc-lead sulphide ores occur mainly in Middle-Triassic rocks represented by ore-bearing dolomites, which consist of the Gogolin and Góra¿d¿e Beds. The greatest documented recoverable resources (C1+ C2 categories according to the Polish terminology) occur in the Gołuchowice (ca. 28 million Mg of Zn–Pb ores; 0.95 million Mg of Zn and 0.23 million Mg of Pb) and Zawiercie I deposits (ca. 17 million Mg of Zn–Pb ores, including ca. 1 million Mg of Zn and 0.4 million Mg of Pb). Inferred mineral resources and volume of ore fields in the Zawiercie II and Marciszów Zn–Pb deposits decreased as compared with the previous estimations based on the old economic criteria and a different method of ore resources calculation (Bołdyriew’s polygons method). It is mostly due to very weak drilling prospecting (C2 + D categories). The total present value of indicated and inferred mineral resources of these four deposits constitute ca. 52.4% of total Zn–Pb ore resources of the Silesian-Cracow Province. The Gołuchowice Zn–Pb deposit was deleated from the Balance of raw material and groundwater resources in Poland in 1993 and restored in 2009 (as of 31.12.2008)