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1. Energy dependence of phi meson production in central Pb+Pb collisions at sqrt(s_nn) = 6 to 17 GeV

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Galadysz, E., Grebieszkow, K., Hegyi, S., Hoehne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kollegger, T., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Kresan, D., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puehlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Stroebele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranic, D., Wetzler, A., Walodarczyk, Z., Yoo, I. K., and Zimanyi, J.

Subjects
Nuclear Experiment
Abstract

Phi meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and to microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies., Comment: 18 pages, 12 figures, 6 tables

Published
2008
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2. Event-by-event transverse momentum fluctuations in nuclear collisions at CERN SPS

Author

Grebieszkow, K., Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Białkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csató, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gál, J., Gaździcki, M., Genchev, V., Georgopoulos, G., Gładysz, E., Hegyi, S., Höhne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Lévai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnár, J., Mrówczyński, St., Nicolic, V., Pálla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Pühlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczyński, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Siklér, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Ströbele, H., Susa, T., Szentpétery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Włodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimányi, J.

Subjects
Nuclear Experiment
Abstract

The latest NA49 results on event-by-event transverse momentum fluctuations are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). Two different methods are applied: evaluating the $\Phi_{p_{T}}$ fluctuation measure and studying two-particle transverse momentum correlations. The obtained results are compared to predictions of the UrQMD model. The results on the energy dependence are compared to the NA49 data on the system size dependence. The NA61 (SHINE, NA49-future) strategy of searching of the QCD critical end-point is also discussed., Comment: proceedings article from CPOD07 (figure 7 - updated, reference 2 - modified)

Published
2007

6. Capture of CO2 by CeO2 Materials of Different Origin and CeO2(75%)ZrO2(25%)

Author

Zdravkova, V., Lagunov, O., Andonova, S., Spassova, I., Ivanova, E., Mihaylov, M., Panayotov, D., and Hadjiivanov, K.

Subjects
FTIR spectroscopy, static and dynamic adsorption, ceria materials, CO2 capture
Abstract

Capturing carbon dioxide from large CO2 emission sources, like power plants and steel mills, is technologically the first important stage of the CCS and CCU approaches aimed at mitigating the global warming. Nowadays, separation of CO2 using liquid sorbents such as amine liquids is a mainstream CO2 capture technology. This separation technique utilizes the temperature dependence of CO2 sorption. Namely, the separation involves cycling between CO2 absorption from exhaust gas at low temperature and CO2 desorption at high temperature. Alternatively, CO2 can be separated by solid materials such as adsorbents and membranes. One of the advantages of solid sorbents as compared to liquid solvents is their smaller specific heat capacity. This allows decreasing the required heat for CO2 recovering and thus lowering the energy consumption for CO2 separation. In this regard, solid-based CO2 adsorbents have attracted a great deal of research efforts. There are many reports on adsorbents using zeolites, metal organic frameworks, amine-grafted silica, carbon-based materials and metal oxides. The investigated metal oxides include cerium oxide, iron oxide, lithium oxide, magnesium oxide, aluminium oxide, titanium oxide, and zirconium oxide. CeO2 is shown to exhibit one of the highest numbers of surface basic sites among a number of selected metal oxides, which is advantageous in terms of CO2 capture. Mesoporous CeO2 is shown to exhibit a significant CO2 adsorption capacity. In addition, the presence of metal dopants was found to further tune the surface functionalities, such as the surface acid–base properties and defect sites, which impact the adsorption behaviour of CO2 on the CeO2 surface. This work studies CeO2 and CeO2-ZrO2 adsorbent materials with different origin. Two of them were commercial nanoparticulate CeO2 powders obtained from two different suppliers, Alfa Aesar and US Research Nanomaterials. Both samples have comparable nanoparticle size and specific surface area. The third CeO2 nanoparticulate sample was prepared in our lab by precipitation with ammonia from of a Ce(NO3)3.6H2O aqueous solution. The fourth nanoparticulate material was CeO2(75%)ZrO2(25%) obtained via co-precipitation with ammonia from of a mixed aqueous solution of Ce(NO3)3.6H2O and ZrO(NO3)2.xH2O. The physicochemical characteristics of the studied samples are reported elsewhere. The CO2 adsorption capacity was measured for both the static and dynamic CO2 adsorption regimes. The chemisorption of CO2 forming different surface species was studied by FTIR spectroscopy. The thermal stability of surface CO2-related species was also studied for the oxygen-activated, H2-reduced and water-covered adsorbents. The FTIR spectroscopy data showed the presence of bridge, hydrogen, mono and bidentate carbonate, as well as polydentate carbonate CO2 surface species. The relative population of these species is almost identical for the commercial CeO2 samples, while for the precipitation prepared samples the coverage of more strongly bonded bi- and polydentate carbonate species is prevailing. Moreover, the CeO2(75%)ZrO2(25%) sample showed almost no indication to loose its CO2 capacity when the surface is pre-covered with water, as was the case with the commercial samples. The results of this study showed that the synthesized CeO2(75%)ZrO2(25%) is a material with promising potential for CO2 capture applications.

Published
2021

7. Inclusive production of charged pions in p + C collisions at 158 GeV/c beam momentum

Author

Alt, C., Baatar, B., Barna, D., Barr, G., Bartke, J., Betev, L., Białkowska, H., Blume, C., Boimska, B., Bracinik, J., Bramm, R., Buncić, P., Cerny, V., Christakoglou, P., Chvala, O., Dinkelaker, P., Dolejsi, J., Eckardt, V., Fischer, H.G., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gaździcki, M., Georgopoulos, G., Höhne, C., Karev, A., Kniege, S., Kollegger, T., Kolesnikov, V.I., Kornas, E., Kowalski, M., Kraus, I., Kreps, M., Litov, L., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mitrovski, M., Pálla, G., Panagiotou, A.D., Panayotov, D., Pattison, C., Petridis, A., Renfordt, R., Rybicki, A., Sandoval, A., Schmitz, N., Seyboth, P., Siklér, F., Stock, R., Ströbele, H., Sziklai, J., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranić, D., Wenig, S., Wetzler, A., Zaranek, J., and The NA Collaboration

Published
2007
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8. Light-induced charge separation in anatase TiO2 particles

Author

Berger, T., Sterrer, M., Diwald, O., Knozinger, E., Panayotov, D., and Thompson, T.L.

Subjects
Oxides -- Electric properties, Oxides -- Magnetic properties, Infrared spectroscopy -- Research, Electron paramagnetic resonance spectroscopy -- Research, Titanium compounds -- Electric properties, Titanium compounds -- Magnetic properties, Chemicals, plastics and rubber industries
Abstract

A study of ultraviolet light-induced electron-hole excitations in anatase TiO2 powders is presented by a combination of electron paramagnetic resonance and infrared spectroscopy measurements. It is concluded that under high vacuum conditions, the major fraction of photoexcited electrons remains in the conduction band.

Published
2005

9. Infestation with protostrongylids of the Balkan chamois (Rupicapra rupicapra balcanica, Bolkey 1925) in Rila National Park, Bulgaria: preliminary data.

Author

Yankov, Y., Georgiev, D., Iliev, P., Tonev, A., Arangelov, S., Valchev, K., Panayotov, D., and Peeva, S.

Subjects
NATIONAL parks & reserves, SAMPLING (Process), FLOTATION, SEDIMENTATION & deposition
Abstract

A total of 109 fecal samples were collected from May to September, 2020 in the area of Rila National Park, Bulgaria. The samples were processed by flotation technique using saturated sodium chloride (sp. gr. 1.20), routine sedimentation method, Baermann's method and larval cultivation. In a total of 59 samples (54.12%) representatives of the family Protostrongylidae were found. The larvae found belong to four genera. The predominant infestations were with Muellerius spp. presented in 35.78% of the studied samples followed by Cystocaulus spp. - in 34.86%, respectively. The genus Protostrongylus was present in 7.34% of the samples, and Neostrongylus - 3.67%. Research on protostrongylid infestation of the Balkan chamois in the area of Rila National Park was carried out for the first time in Bulgaria. [ABSTRACT FROM AUTHOR]

Published
2022

12. Amino acid composition of lamb meat from the North East Bulgarian fine fleece breed and its crossbreds from internal breeding

Author

Slavov, R., Mihaylova, G., Ribarski, S., Panayotov, D., Pamukova, D., and Dragnev, D.

Subjects
amino acid content of meat, meat, crossing, lambs, internal breeding, amino acid index of mea
Abstract

A comparative analysis of amino acid composition of lamb meat from the North East Bulgarian fine fleece breed (I gr.) and its crossbreds from internal breeding with 25% heredity from the Australian merino (II gr.) and Ile de France (III gr.) breeds was conducted. Upon starting the experiment lambs were equal and during the experiment they were placed under similar conditions of feeding and rearing. To establish the amino acid composition of meat slaughter analyses were performed at 100 and 130 days of age. From the carcass of each slaughtered animal individual mean samples were taken. Studies were carried out in the Research Laboratory of the Faculty of Agriculture at Trakia University. As a result of the studies the following conclusions were made: 1⁄4 Ile de France crossbreds in a sophisticated crossing have the highest total amino acid content, including essential amino acids in the meat of 100- and 130-day-old lambs, 6.87% and 7.36%, respectively. The lysine/arginine ratio, relating to protein atherogenicity, varies within narrow ranges among groups and marks slight increase with age – from 1.31-1.37 at 100 days to 1.41-1.46 at 130 days. With the increase of age in crossbreds from internal breeding total protein amino acid content grows, that being most prominent in lambs from the III group – from 41.92 to 43.49%. The values of total protein indices increase compared to the reference protein (from 117.97% to 118.22% for II group and from 116.44% to 120.80% for III group) and the whole egg protein (from 89.39% to 91.92% for II group and from 90.53% to 93.93 for III group). It has been found that internal breeding of crossbreds with 25% heredity from the Ile de France breed has positive effect concerning the total amino acid content of lamb meat at 100 and 130 days of age, essential amino acid content in it and the levels of total amino acid indices. Internal breeding of crossbreds with 25% heredity from the Australian merino breed does not have an adverse effect on the levels of the studied traits.

Published
2016

13. Molecular diffusion and photooxidation chemistry on TiO2 surfaces under perfluoroalkane layers

Author

Panayotov, D. and Yates, J.T., Jr.

Subjects
Photochemistry -- Research, Organic compounds -- Research, Organic compounds -- Properties, Infrared spectroscopy -- Research, Chemicals, plastics and rubber industries
Abstract

The transmission infrared spectroscopy is used to analyze the photooxidation of an organic compound, 2-chloroethyl ethyl sulfide (2-CEES), over a TiO2-SiO2 mixed oxide photocatalyst for determining the influence of an inert perfluoroalkane (C9F20) buffer layer on the photooxidation properties of the photocatalyst. The study revealed that adsorption of 2-CEES and O2 occurs at the photocatalyst surface, and photooxidation of the 2-CEES is little impeded by the inert C9F20 layer.

Published
2004

15. High Transverse Momentum Hadron Spectra at $\sqrt{s_{NN}}=17.3$ GeV, in Pb+Pb and p+p Collisions, Measured by CERN-NA49

Author

Anticic, T, Baatar, B, Barna, D, Bartke, J, Betev, L, Bialkowska, H, Blume, C, Boimska, B, Botje, M, Bracinik, J, Bramm, R, Buncic, P, Cerny, V, Christakoglou, P, Chung, P, Chvala, O, Cramer, J G, Csató, P, Dinkelaker, P, Eckardt, V, Flierl, D, Fodor, Z, Foka, P, Friese, V, Gál, J, Gazdzicki, M, Genchev, V, Georgopoulos, G, Gladysz-Dziadus, E, Grebieszkow, K, Hegyi, S, Höhne, C, Kadija, K, Karev, A, Kikola, D, Kliemant, M, Kniege, S, Kolesnikov, V I, Kornas, E, Korus, R, Kowalski, M, Kraus, I, Kreps, M, Laszlo, A, Lacey, R, Van Leeuwen, M, Lévai, Peter, Litov, L, Lungwitz, B, Makariev, M, Malakhov, A I, Mateev, M, Melkumov, G L, Mischke, A, Mitrovski, M, Molnár, J, Mrówczynski, S, Nicolic, V, Pálla, G, Panagiotou, A D, Panayotov, D, Petridis, A, Peryt, W, Pikna, M, Pluta, J, Prindle, D, Pühlhofer, F, Renfordt, R, Roland, C, Roland, G, Rybczynski, M, Rybicki, A, Sandoval, A, Schmitz, N, Schuster, T, Seyboth, P, Siklér, F, Sitár, B, Skrzypczak, E, Slodkowski, M, Stefanek, G, Stock, R, Strabel, C, Ströbele, H, Susa, T, Szentpétery, I, Sziklai, J, Szuba, M, Szymanski, P, Trubnikov, V, Varga, D, Vassiliou, M, Veres, G I, Vesztergombi, G, Vranic, D, Wetzler, A, Wlodarczyk, Z, Wojtaszek, A, Yoo, I K, and Zimányi, J

Subjects
Nuclear Physics - Experiment, Nuclear Experiment
Abstract

Transverse momentum spectra up to 4.5 GeV/c around midrapidity of $\pi^{\pm}, p, pbar, K^{\pm}$ in Pb+Pb reactions were measured at $\sqrt{s_{NN}}=17.3$ GeV by the CERN-NA49 experiment. The nuclear modification factors $R_{AA}$ and $R_{CP}$ were extracted and are compared to RHIC results at $\sqrt{s_{NN}}=200$ GeV. The modification factor $R_{AA}$ shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor $R_{CP}$, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the $\pi^{\pm}$ channel. The extracted $R_{CP}$ values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for $\pi^{\pm}$ above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.

Published
2012

16. Study of milk composition in sheep of Pleven black head breed

Author

Panayotov, D., Iliev, T., Naydenova, N., Pamukova, D., and Simeonov, M.

Subjects
milk composition, line, rams, sheep milk, somatic cells
Abstract

The aim of the study was to investigate somatic cell count and milk composition from Pleven Black head breed of sheep. A total of 96 ewes on first lactation were used belonging to the flock of the village of Komarevo, Pleven district. The studied animals – daughters of six rams from 2 lines, were fed year round in a barn (November-March) and pasture period (April-October). A total of 384 individual milk samples were taken at four selection controls. The milk composition – fat, protein, casei, lactose, solids-non-fat and dry matter was established by Milko-Skan 104 (A/S Foss Elektric, Denmark). The total number of the somatic cells was established by an Ekoscope SCC automated system (Bulteh 2000, Stara Zagora, Bulgaria). The results of this investigation showed that the studied animals had very good milk quality indices. The milk of line 522 animals had significantly higher dry matter, solids-non-fat, fat, protein, casein and lactose content in comparison to those of line 32. For all studied milk indicators the daughters of ram No.33 in line 32 showed the highest average values whereas those of ram No.321 belonging to the same line had the lowest. The average somatic cell count of the milk in the studied animals was very low – 66 254 cells/ml. Minimum variation was established in respect to average SCC values of the milk in both lines but very large between the individual rams.

Published
2011

17. Three-dimensional two-pion source image from Pb +Pb collisions at √sNN = 17.3 GeV : New constraints for source breakup dynamics

Author

Alt, C., Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kniege, S., Kolesnikov, V. I., Korus, R., Kowalski, M., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mitrovski, M., Molnar, J., Mrowczynski, St., Nikolić, Vedran, Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., Alexanders, J. M., Danielewicz, P., Kisiel, A., and Pratt, S.

Subjects
Physics, Nuclear Theory, Physics::Accelerator Physics, CERN, SPS, NA49, source imaging, pions, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Source imaging methodology is used to provide a three-dimensional two-pion source function for midrapidity pion pairs with pT < 70 MeV/c in central (0–7%) Pb + Pb collisions at √sNN = 17.3 GeV. Prominent non-Gaussian tails are observed in the pion pair transverse momentum (outward) and in the beam (longitudinal) directions. Model calculations reproduce them with the assumption of Bjorken longitudinal boost invariance and transverse flow blast-wave dynamics ; they also yield a proper time for breakup and emission duration for the pion source.

Published
2010

18. Status and further Analysis Plans of the NA49 Collaboration

Author

Anticic, T, Baatar, B, Barna, D, Bartke, J, Beck, H, Betev, L, Bialkowska, H, Blume, C, Boimska, B, Book, J, Botje, M, Bracinik, J, Buncic, P, Cerny, V, Christakoglou, P, Chung, P, Chvala, O, Cramer, J G, Csató, P, Dinkelaker, P, Eckardt, V, Fischer, H G, Fodor, Z, Foka, P, Friese, V, Gál, J, Gazdzicki, M, Genchev, V, Grebieszkow, K, Hegyi, S, Höhne, C, Kadija, K, Karev, A, Kolesnikov, V I, Kowalski, M, Kreps, M, Laszlo, A, Lacey, R, Van Leeuwen, M, Lévai, Peter, Litov, L, Makariev, M, Malakhov, A I, Mateev, M, Mackowiak, M, Melkumov, G L, Mitrovski, M, Molnár, J, Mrówczynski, St, Nicolic, V, Pálla, G, Panagiotou, A D, Panayotov, D, Peryt, W, Pikna, M, Pluta, J, Prindle, D, Pühlhofer, F, Renfordt, R, Roland, C, Roland, G, Rybczynski, M, Rybicki, A, Sandoval, A, Schmitz, N, Schuster, T, Seyboth, P, Siklér, F, Sitár, B, Skrzypczak, E, Slodkowski, M, Stefanek, G, Stock, R, Ströbele, H, Susa, T, Szentpétery, I, Sziklai, J, Szuba, M, Szymanski, P, Utvic, M, Varga, D, Vassiliou, M, Veres, G I, Vesztergombi, G, Vranic, D, Wenig, S, Wlodarczyk, Z, and Wojtaszek, A

Subjects
Detectors and Experimental Techniques
Abstract

Status and further Analysis Plans of the NA49 Collaboration

Published
2009

19. System-size dependence of $\Lambda$ and $\Xi$ production in nucleus-nucleus collisions at 40A and 158A GeV measured at the CERN Super Proton Synchrotron

Author

Anticic, T., Baatar, B., Barna, D., Bartke, J., Beck, H., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Book, J., Botje, M., Bracinik, J., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kresan, D., Kolesnikov, V.I., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Meurer, C., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Utvic, M., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wlodarczyk, Z., Wojtaszek, A., and Yoo, I.K.

Subjects
FOS: Physical sciences, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Results on Lambda, Anti-lambda, and Xi- production in centrality selected Pb+Pb reactions at 40A and 158A GeV and in near-central C+C and Si+Si reactions at 158A GeV are presented. Transverse mass spectra, rapidity spectra, and multiplicities in dependence of the system size are discussed. Comparisons to transport models (UrQMD2.3 and HSD) and to the core-corona approach are performed. While Lambda and Anti-lambda production can be described by transport models reasonably well, these models do not agree with the Xi- measurements. On the other hand, the core-corona picture fits very well the system-size dependence of Lambda and Xi-, while it agrees less well with the Anti-lambda data., 13 pages, 12 figures. Revised version as accepted by Phys. Rev. C

Published
2009

20. Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from sqrt(sNN)=6.3 to 17.3 GeV

Author

Alt, C., Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Kresan, D., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, S., Nikolić, Vedran, Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Pikna, M., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Stefanek, G., Stock, R., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wetzler, A., Wlodarczyk, Z., and Yoo, I. K.

Subjects
NA49, SPS, fluctuation, particle ratio, energy dependence, Physics, Nuclear Experiment
Abstract

We present measurements of the energy dependence of event-by-event fluctuations in the K/pi and (p+ anti-p)/pi multiplicity ratios in heavy-ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, sqrt(sNN), between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of nonstatistical fluctuations at each energy. For the K/pi ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p+anti-p)/pi ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase toward lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/pi ratio fluctuations.

Published
2009

21. System-size dependence of Λ and Ξ production in nucleus-nucleus collisions at 40A and 158A GeV measured at the CERN Super Proton Synchrotron

Author

Anticic, T. Baatar, B. Barna, D. Bartke, J. Beck, H. Betev, L. Białkowska, H. Blume, C. Boimska, B. Book, J. Botje, M. Bracinik, J. Bunčić, P. Cerny, V. Christakoglou, P. Chung, P. Chvala, O. Cramer, J.G. Csató, P. Dinkelaker, P. Eckardt, V. Fodor, Z. Foka, P. Friese, V. Gál, J. Gaździcki, M. Genchev, V. Grebieszkow, K. Hegyi, S. Höhne, C. Kadija, K. Karev, A. Kresan, D. Kolesnikov, V.I. Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. Lacey, R. Leeuwen, M.V. Lévai, P. Litov, L. Lungwitz, B. Makariev, M. Malakhov, A.I. Mateev, M. Melkumov, G.L. Meurer, C. Mischke, A. Mitrovski, M. Molnár, J. Mrówczyński, S. Nicolic, V. Pálla, G. Panagiotou, A.D. Panayotov, D. Petridis, A. Peryt, W. Pikna, M. Pluta, J. Prindle, D. Pühlhofer, F. Renfordt, R. Roland, C. Roland, G. Rybczyński, M. Rybicki, A. Sandoval, A. Schmitz, N. Schuster, T. Seyboth, P. Siklér, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. Strabel, C. Ströbele, H. Susa, T. Szentpétery, I. Sziklai, J. Szuba, M. Szymanski, P. Utvić, M. Varga, D. Vassiliou, M. Veres, G.I. Vesztergombi, G. Vranić, D. Włodarczyk, Z. Wojtaszek, A. Yoo, I.K.

Abstract

Results on Λ, Λ̄, and Ξ- production in centrality selected Pb+Pb reactions at 40A and 158A GeV and in near-central C+C and Si+Si reactions at 158A GeV are presented. Transverse mass spectra, rapidity spectra, and multiplicities in dependence of the system size are discussed. Comparisons to transport models (ultrarelativistic quantum molecular dynamics and hadron string dynamics) and to the core-corona approach are performed. Although Λ and Λ̄ production can be described by transport models reasonably well, these models do not agree with the Ξ- measurements. However, the core-corona picture fits very well the system-size dependence of Λ and Ξ-, whereas it agrees less well with the Λ̄ data. © 2009 The American Physical Society.

Published
2009

22. Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from sNN=6.3 to 17.3 GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. Betev, L. Białkowska, H. Blume, C. Boimska, B. Botje, M. Bracinik, J. Bramm, R. Bunčcić, P. Cerny, V. Christakoglou, P. Chvala, O. Cramer, J.G. Csató, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gál, J. Gazdzicki, M. Genchev, V. Georgopoulos, G. Gładysz, E. Grebieszkow, K. Hegyi, S. Höhne, C. Kadija, K. Karev, A. Kliemant, M. Kniege, S. Kolesnikov, V.I. Kornas, E. Korus, R. Kowalski, M. Kraus, I. Kreps, M. Kresan, D. Van Leeuwen, M. Lévai, P. Litov, L. Lungwitz, B. Makariev, M. Malakhov, A.I. Mateev, M. Melkumov, G.L. Mischke, A. Mitrovski, M. Molnár, J. Mrówczyński, St. Nicolic, V. Pálla, G. Panagiotou, A.D. Panayotov, D. Petridis, A. Pikna, M. Prindle, D. Pühlhofer, F. Renfordt, R. Roland, C. Roland, G. Rybczyński, M. Rybicki, A. Sandoval, A. Schmitz, N. Schuster, T. Seyboth, P. Siklér, F. Sitar, B. Skrzypczak, E. Stefanek, G. Stock, R. Ströbele, H. Susa, T. Szentpétery, I. Sziklai, J. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G.I. Vesztergombi, G. Vranić, D. Wetzler, A. Włodarczyk, Z. Yoo, I.K.

Subjects
Nuclear Experiment
Abstract

We present measurements of the energy dependence of event-by-event fluctuations in the K/π and (p+p̄)/π multiplicity ratios in heavy-ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, sNN, between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of nonstatistical fluctuations at each energy. For the K/π ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p+p̄)/π ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase toward lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/π ratio fluctuations. © 2009 The American Physical Society.

Published
2009

23. The NA49 Collaboration

Author

Anticic, T. Baatar, B. Barna, D. Bartke, J. Beck, H. Betev, L. Białkowska, H. Blume, C. Boimska, B. Book, J. Botje, M. Bracinik, J. Bunčić, P. Cerny, V. Christakoglou, P. Chung, P. Chvala, O. Cramer, J.G. Csató, P. Dinkelaker, P. Eckardt, V. Fischer, H.G. Fodor, Z. Foka, P. Friese, V. Gál, J. Gaździcki, M. Genchev, V. Grebieszkow, K. Hegyi, S. Höhne, C. Kadija, K. Karev, A. Kolesnikov, V.I. Kowalski, M. Kreps, M. Laszlo, A. Lacey, R. van Leeuwen, M. Lévai, P. Litov, L. Lungwitz, B. Makariev, M. Malakhov, A.I. Mateev, M. Melkumov, G.L. Mitrovski, M. Molnár, J. Mrówczyński, St. Nicolic, V. Pálla, G. Panagiotou, A.D. Panayotov, D. Peryt, W. Pikna, M. Pluta, J. Prindle, D. Pühlhofer, F. Renfordt, R. Roland, C. Roland, G. Rybczyński, M. Rybicki, A. Sandoval, A. Schmitz, N. Schuster, T. Seyboth, P. Siklér, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. Ströbele, H. Susa, T. Szentpétery, I. Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Utvić, M. Varga, D. Vassiliou, M. Veres, G.I. Vesztergombi, G. Vranić, D. Wenig, S. Włodarczyk, Z. Wojtaszek, A.

Published
2009

24. Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV

Author

Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kikola, D, Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, S., Nikolić, Vedran, Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Utvic, M., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wlodarczyk, Z., Wojtaszek, A., and Yoo, I. K.

Subjects
NA49, SPS, QGP, fluctuation, transverse momenta, Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, Particle Physics - Experiment
Abstract

Results are presented on event-by-event fluctuations of transverse momenta $p_T$ in central Pb+Pb interactions at 20$A$, 30$A$, 40$A$, 80$A$, and 158$A$ GeV. The analysis was performed for charged particles at forward center-of-mass rapidity ($1.1 < y^{*}_�� < 2.6$). Three fluctuation measures were studied: the distribution of average transverse momentum - $M(p_T)$ - in the event, the $��_{p_{T}}$ fluctuation measure and two-particle transverse momentum correlations. Fluctuations of $p_T$ are small and show no significant energy dependence in the energy range of the CERN Super Proton Synchrotron. Results are compared with QCD-inspired predictions for the critical point, and with the UrQMD model. Transverse momentum fluctuations, similar to multiplicity fluctuations, do not show the increase expected for freeze-out near the critical point of QCD., Published in Phys. Rev. C

Published
2008

25. Energy dependence of phi meson production in central Pb+Pb collisions sqrt(sNN) = 6 to 17 GeV

Author

Alt, C., Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kollegger, T., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Kresan, D., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nikolić, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wetzler, A., Wlodarczyk, Z., Yoo, I. K., and Zimanyi, J.

Subjects
CERN, SPS, QGP, Pb+Pb, strange particle, phi, energy dependence, Physics, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Phi meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and with microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies.

Published
2008

26. Status and further Analysis Plans of the NA49 Collaboration

Author

Seyboth, Peter, Anticic, T, Baatar, B, Barna, D, Bartke, J, Beck, H, Betev, L, Bialkowska, H, Blume, C, Boimska, B, Book, J, Botje, M, Bracinik, J, Buncic, P, Cerny, V, Christakoglou, P, Chung, P, Chvala, O, Cramer, J G, Csató, P, Dinkelaker, P, Eckardt, V, Fischer, H G, Fodor, Z, Foka, P, Friese, V, Gál, J, Gazdzicki, M, Genchev, K, Grebieszkow, V, Hegyi, C, Hohne, K, Kadija, K, Karev, A, Kikola, D, Kolesnikov, V I, Kowalski, M, Kreps, M, Laszlo, A, Lacey, R, Van Leeuwen, M, Lévai, Peter, Litov, L, Lungwitz, B, Makariev, M, Malakhov, A I, Mateev, M, Melkumov, G L, Mitrovski, M, Molnár, J, Mrówczynski, S, Nicolic, V, Pálla, G, Panagiotou, A D, Panayotov, D, Peryt, W, Pikna, M, Pluta, J, Prindle, D, Pühlhofer, F, Renfordt, R, Roland, C, Roland, G, Rybczynski, M, Rybicki, A, Sandoval, N, Schmitz, A, Schuster, T, Seyboth, P, Sikler, B, Sitar, F, Skrzypczak, E, Slodkowski, M, Stefanek, G, Stock, R, Ströbele, H, Susa, T, Szentpétery, I, Sziklai, J, Szuba, M, Szymanski, P, Trubnikov, V, Utvic, M, Varga, D, Vranic, M, Vassiliou, G I, Veres, G, Vesztergombi, D, Vranic, D, Wenig, S, Wlodarczyk, Z, Wojtaszek, A, and Yoo, I K

Subjects
Detectors and Experimental Techniques
Abstract

Status report 2008 of the NA49 collaboration to the SPSC

Published
2008

27. Energy dependence of Lambda and Xi production in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV measured at the CERN Super Proton Synchrotron

Author

Alt, C., Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kikola, D, Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Meurer, C., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nikolić, Vedran, Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Utvic, M., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimanyi, J.

Subjects
CERN, SPS, QGP, Pb+Pb, strange particle, Lambda, Xi, energy dependence, Physics, Nuclear Theory, Nuclear Experiment
Abstract

Results on Lambda, anti-Lambda, Xi-, and antiXi+ production in central Pb+Pb reactions at 20A, 30A, 40A, 80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. Although the latter provide a reasonable description of all particle yields, the first class of models fails to match the Xi- and anti-Xi+ multiplicities.

Published
2008

28. Energy dependence of multiplicity fluctuations in heavy ion collisions at 20A to 158A GeV

Author

Alt, C., Antičić, Tome, Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, Predrag, Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nikolić, Vedran, Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Utvic, M., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, Danilo, Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimanyi, J.

Subjects
Physics, NA49, CERN, SPS, QGP, fluctuations, multiplicity, energy dependence, Nuclear Experiment
Abstract

Multiplicity fluctuations of positively, negatively, and all charged hadrons in the forward hemisphere were studied in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV. The multiplicity distributions and their scaled variances omega are presented as functions of their dependence on collision energy as well as on rapidity and transverse momentum. The distributions have bell-like shapes and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point in fluctuations are observed. The string-hadronic ultrarelativistic quantum molecular dynamics (UrQMD) model significantly overpredicts the mean, but it approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on fluctuations in relativistic systems.

Published
2008

29. Three-Dimensional two-pion source image from Pb+Pb Collisions at Sqrts_NN=17.3 GeV: New constraints for source breakup dynamics

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I.K., Zimanyi, J., Alexander, J.M., Danielewicz, P., Kisiel, A., and Pratt, S.

Subjects
Nuclear Theory, FOS: Physical sciences, Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Source imaging methodology is used to provide a three-dimensional two-pion source function for mid-rapidity pion pairs with $p_T, Six pages 4 figs. Submitted for publication

Published
2008

30. Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from $\sqrt{s_{_{NN}}} =$~6.3 to 17.3 GeV

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Kresan, D., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Pikna, M., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Stefanek, G., Stock, R., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Yoo, I.K., and Zimanyi, J.

Subjects
FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

We present measurements of the energy dependence of event-by-event fluctuations in the K/pi and (p + \bar{p})/pi multiplicity ratios in heavy ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, \sqrt{s_{_{NN}}}, between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of non-statistical fluctuations at each energy. For the K/pi ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p + \bar{p})/pi ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase towards lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/pi ratio fluctuations., Comment: 11 pages, 10 figures, update to published version

Published
2008

31. Energy dependence of $\Lambda$ and $\Xi$ production in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV measured at the CERN Super Proton

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Meurer, C., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Richard, A., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Utvic, M., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I.K., and Zimanyi, J.

Subjects
Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Results on $\Lambda$, $\bar{\Lambda}}$, $\Xi^{-}$, and $\bar{\Xi}^{+}$ production in central Pb+Pb reactions at 20A, 30A, 40A, 80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. While the latter provide a reasonable description of all particle yields, the first class of models fails to match the $\Xi^{-}$, and $\bar{\Xi}^{+}$ multiplicities., Comment: 16 pages, 16 figures. Finally published version after editorial revision

Published
2008

32. High transverse momentum hadron spectra at sqrt(sNN)=17.3 GeV in Pb+Pb and p+p collisions

Author

Alt, C., Antičić, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D, Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, S., Nikolić, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimanyi, J.

Subjects
Physics, Nuclear Experiment, NA49, SPS, Pb+Pb, p+p, high transverse momentum, hadron
Abstract

Transverse momentum spectra up to 4.5 GeV/c around midrapidity of pi+-, p, anti-p, and K+- in Pb+Pb reactions were measured at sqrt(sNN)=17.3 GeV by the CERN-NA49 experiment. The nuclear modification factors RAA for pi+- and RCP for pi+-, p, anti-p, K+- were extracted and compared with results obtained at the BNL Relativistic Heavy Ion Collider (RHIC) at sqrt(sNN)=200 GeV. The modification factor RAA shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor RCP, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the pi+- channel. The extracted RCP values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for pi+- above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.

Published
2008

33. Pion and kaon production in central Pb plus Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. G. and Genchev, V. Gladysz, E. Grebieszkow, K. Hegyi, S. and Hoehne, C. Kadija, K. Karev, A. Kikola, D. Kliemant, M. and Kniege, S. Kolesnikov, V. I. Kollegger, T. Kornas, E. and Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. Lacey, R. van Leeuwen, M. Levai, P. Litov, L. Lungwitz, B. and Makariev, M. Malakhov, A. I. Mateev, M. Melkumov, G. L. and Mischke, A. Mitrovski, M. Molnar, J. Mrowczynski, St and Nicolic, V. Palla, G. Panagiotou, A. D. Panayotov, D. and Petridis, A. Peryt, W. Pikna, M. Pluta, J. Prindle, D. and Uhlhofer, F. P. Renfordt, R. Roland, C. Roland, G. and Rybczynski, M. Rybicki, A. Sandoval, A. Schmitz, N. and Schuster, T. Seyboth, P. Sikler, F. Sitar, B. and Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Obele, H. Str Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. Vranic, D. Wetzler, A. Wlodarczyk, Z. Yoo, I. K. Zimanyi, J. and NA49 Collaboration

Subjects
Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.

Published
2008

34. High transverse momentum hadron spectra at root s(NN)=17.3 GeV in Pb+Pb and p+p collisions

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. and Genchev, V. Georgopoulos, G. Gladysz, E. Grebieszkow, K. and Hegyi, S. Hoehne, C. Kadija, K. Karev, A. Kikola, D. and Kliemant, M. Kniege, S. Kolesnikov, V. I. Kornas, E. and Korus, R. Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. and Lacey, R. van Leeuwen, M. Levai, P. Litov, L. and Lungwitz, B. Makariev, M. Malakhov, A. I. Mateev, M. and Melkumov, G. L. Mischke, A. Mitrovski, M. Molnar, J. and Mrowczynski, St. Nicolic, V. Palla, G. Panagiotou, A. D. and Panayotov, D. Petridis, A. Peryt, W. Pikna, M. Pluta, J. and Prindle, D. Puehlhofer, F. Renfordt, R. Roland, C. and Roland, G. Rybczynski, M. Rybicki, A. Sandoval, A. and Schmitz, N. Schuster, T. Seyboth, P. Sikler, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Stroeble, H. Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. Vranic, D. Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. Yoo, I. K. and Zimanyi, J. NA49 Collaboration

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

Transverse momentum spectra up to 4.5 GeV/c around midrapidity of pi(+/-), p, (p) over bar, and K-+/- in Pb+Pb reactions were measured at root s(NN) = 17.3 GeV by the CERN-NA49 experiment. The nuclear modification factors R-AA for pi(+/-) and R-CP for pi(+/-), p, (p) over bar, K-+/- were extracted and compared with results obtained at the BNL Relativistic Heavy Ion Collider (RHIC) at root s(NN) = 200 GeV. The modification factor R-AA shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor R-CP, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the pi(+/-) channel. The extracted R-CP values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for pi(+/-) above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.

Published
2008

35. Bose-Einstein correlations of pi(-)pi(-) pairs in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. and Genchev, V. Georgopoulos, G. Gladysz, E. Grebieszkow, K. and Hegyi, S. Hoehne, C. Kadija, K. Karev, A. Kikola, D. and Kliemant, M. Kniege, S. Kolesnikov, V. I. Kornas, E. and Korus, R. Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. and Lacey, R. van Leeuwen, M. Levai, P. Litov, L. and Lungwitz, B. Makariev, M. Malakhov, A. I. Mateev, M. and Melkumov, G. L. Mischke, A. Mitrovski, M. Molnar, J. and Mrowczynski, St. Nicolic, V. Palla, G. Panagiotou, A. D. and Panayotov, D. Petridis, A. Peryt, W. Pikna, M. Pluta, J. and Prindle, D. Puehlhofer, F. Renfordt, R. Roland, C. and Roland, G. Rybczynski, M. Rybicki, A. Sandoval, A. and Schmitz, N. Schuster, T. Seyboth, P. Sikler, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Stroebele, H. Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. Vranic, D. Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. Yoo, I. K. and Zimanyi, J.

Subjects
Nuclear Experiment
Abstract

Measurements of Bose-Einstein correlations of pi(-)pi(-) pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN Super Proton Synchroton for beam energies of 20A,30A,40A,80A, and 158A GeV. Correlation functions were measured in the longitudinally comoving “out-side-long” reference frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse-momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse-momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed.

Published
2008

36. Energy dependence of Lambda and Xi production in central Pb plus Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV measured at the CERN Super Proton Synchrotron

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. and Genchev, V. Gladysz, E. Grebieszkow, K. Hegyi, S. and Hoehne, C. Kadija, K. Karev, A. Kikola, D. Kliemant, M. and Kniege, S. Kolesnikov, V. I. Kornas, E. Kowalski, M. and Kraus, I. Kreps, M. Laszlo, A. Lacey, R. van Leeuwen, M. and Levai, P. Litov, L. Lungwitz, B. Makariev, M. and Malakhov, A. I. Mateev, M. Melkumov, G. L. Meurer, C. and Mischke, A. Mitrovski, M. Molnar, J. Mrowczynski, St. and Nicolic, V. Palla, G. Panagiotou, A. D. Panayotov, D. and Petridis, A. Peryt, W. Pikna, M. Pluta, J. Prindle, D. and Puehlhofer, F. Renfordt, R. Richard, A. Roland, C. and Roland, G. Rybczynski, M. Rybicki, A. Sandoval, A. and Schmitz, N. Schuster, T. Seyboth, P. Sikler, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Stroebele, H. Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Utvic, M. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. and Vranic, D. Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. and Yoo, I. K. Zimanyi, J. NA49 Collaboration

Subjects
Nuclear Theory, High Energy Physics::Phenomenology, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Results on Lambda, (Lambda) over bar, Xi(-), and (Xi) over bar (+) production in central Pb+Pb reactions at 20A, 30A, 40A, 80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. Although the latter provide a reasonable description of all particle yields, the first class of models fails to match the Xi(-) and (Xi) over bar (+) multiplicities.

Published
2008

37. Energy dependence of multiplicity fluctuations in heavy ion collisions at 20A to 158A GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. and Genchev, V. Georgopoulos, G. Gladysz, E. Grebieszkow, K. and Hegyi, S. Hoehne, C. Kadija, K. Karev, A. Kikola, D. and Kliemant, M. Kniege, S. Kolesnikov, V. I. Kornas, E. and Korus, R. Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. and Lacey, R. van Leeuwen, M. Levai, P. Litov, L. and Lungwitz, B. Makariev, M. Malakhov, A. I. Mateev, M. and Melkumov, G. L. Mischke, A. Mitrovski, M. Molnar, J. and Mrowczynski, St. Nicolic, V. Palla, G. Panagiotou, A. D. and Panayotov, D. Petridis, A. Peryt, W. Pikna, M. Pluta, J. and Prindle, D. Puehlhofer, F. Renfordt, R. Roland, C. and Roland, G. Rybczynski, M. Rybicki, A. Sandoval, A. and Schmitz, N. Schuster, T. Seyboth, P. Sikler, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Stroebele, H. Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Utvic, M. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. and Vranic, D. Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. and Yoo, I. K. Zimanyi, J.

Subjects
Nuclear Experiment
Abstract

Multiplicity fluctuations of positively, negatively, and all charged hadrons in the forward hemisphere were studied in central Pb+ Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV. The multiplicity distributions and their scaled variances. are presented as functions of their dependence on collision energy as well as on rapidity and transverse momentum. The distributions have bell-like shapes and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point in fluctuations are observed. The string-hadronic ultrarelativistic quantum molecular dynamics (UrQMD) model significantly overpredicts the mean, but it approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on fluctuations in relativistic systems.

Published
2008

38. Energy dependence of meson production in central Pb+Pb collisions at sNN=6 to 17 GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. Betev, L. Białkowska, H. Blume, C. Boimska, B. Botje, M. Bracinik, J. Bramm, R. Bunčić, P. Cerny, V. Christakoglou, P. Chung, P. Chvala, O. Cramer, J.G. Csató, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gál, J. Gaździcki, M. Genchev, V. Georgopoulos, G. Gładysz, E. Grebieszkow, K. Hegyi, S. Höhne, C. Kadija, K. Karev, A. Kikola, D. Kliemant, M. Kniege, S. Kolesnikov, V.I. Kollegger, T. Kornas, E. Korus, R. Kowalski, M. Kraus, I. Kreps, M. Kresan, D. Laszlo, A. Lacey, R. Van Leeuwen, M. Lévai, P. Litov, L. Lungwitz, B. Makariev, M. Malakhov, A.I. Mateev, M. Melkumov, G.L. Mischke, A. Mitrovski, M. Molnár, J. Mrówczyński, S. Nicolic, V. Pálla, G. Panagiotou, A.D. Panayotov, D. Petridis, A. Peryt, W. Pikna, M. Pluta, J. Prindle, D. Pühlhofer, F. Renfordt, R. Roland, C. Roland, G. Rybczyński, M. Rybicki, A. Sandoval, A. Schmitz, N. Schuster, T. Seyboth, P. Siklér, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. Strabel, C. Ströbele, H. Susa, T. Szentpétery, I. Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G.I. Vesztergombi, G. Vranić, D. Wetzler, A. Włodarczyk, Z. Yoo, I.K. Zimányi, J.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

Meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and with microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies. © 2008 The American Physical Society.

Published
2008

39. Pion and kaon production in central Pb plus Pb collisions at 20A and 30A GeV: evidence for the onset of deconfinement

Author

Antičić, Tome, Alt, C., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, Krešo, Karev, A., Kikola, D, Kliemant, M., Kniege, S., Kolesnikov, V. I., Kollegger, T., Kornas, E., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, S., Nikolić, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, Tatjana, Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimanyi, J.

Subjects
CERN, NA49, Pb+Pb, pion, kaon, deconfinement, Physics, Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.

Published
2008

40. Energy dependence of multiplicity fluctuations in heavy ion collisions at 20A to 158A GeV

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, Helena, Blume, Christoph, Boimska, B., Botje, Michiel, Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Zoltan, Foka, P., Friese, Volker, Gal, J., Gazdzicki, Marek, Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, Roy A., van Leeuwen, M., Levai, P., Litov, Leandar, Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, Apostolos D., Panayotov, D., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, Gunther, Rybczynski, M., Rybicki, A., Sandoval, Andres, Schmitz, Norbert, Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, Grzegorz, Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Utvic, M., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., and Yoo, I.K.

Subjects
Nuclear Physics - Experiment, Nuclear Experiment
Abstract

Multiplicity fluctuations of positively, negatively and all charged hadrons in the forward hemisphere were studied in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV. The multiplicity distributions and their scaled variances $\omega$ are presented in dependence of collision energy as well as of rapidity and transverse momentum. The distributions have bell-like shape and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point fluctuations are observed. The string-hadronic model UrQMD significantly overpredicts the mean, but approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on fluctuations in relativistic gases. Multiplicity fluctuations of positively, negatively and all charged hadrons in the forward hemisphere were studied in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV. The multiplicity distributions and their scaled variances are presented in dependence of collision energy as well as of rapidity and transverse momentum. The distributions have bell-like shape and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point in fluctuations are observed. The string-hadronic model UrQMD significantly overpredicts the mean, but approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on fluctuations in relativistic systems.

Published
2007

41. Bose-Einstein correlations of $\pi^{-}\pi^{-}$ pairs in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV

Author

Alt, C., Antičić, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D, Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, S., Nikolić, V., Palla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W, Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Šuša, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I. K., and Zimanyi, J.

Subjects
Physics, Nuclear Theory, Nuclear Physics - Experiment, SPS, pion, bose-einstein, correlations, QGP, Pb+Pb, Nuclear Experiment
Abstract

Measurements of Bose-Einstein correlations of pi-pi- pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN Super Proton Synchroton for beam energies of 20A, 30A, 40A, 80A, and 158A GeV. Correlation functions were measured in the longitudinally co-moving ``out-side-long'' reference frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed.

Published
2007

42. Recent results on (anti)nucleus and (anti)hyperon production in nucleus-nucleus collisions at CERN SPS energies

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Białkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csató, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gál, J., Gaździcki, M., Genchev, V., Georgopoulos, G., Gładysz, E., Grebieszkow, K., Hegyi, S., Höhne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., Leeuwen, M., Lévai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnár, J., Mrówczyński, St, Nicolic, V., Pálla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Pühlhofer, F., Renfordt, R., Roland, C., Roland, G., Maciej Rybczynski, Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Siklér, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Ströbele, H., Susa, T., Szentpétery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Włodarczyk, Z., Wojtaszek, A., Yoo, I. K., Zimányi, J., and Melkumov, G.

Subjects
Mass number, Physics, Nuclear Theory, Hyperon, FOS: Physical sciences, Inverse, Strangeness, 7. Clean energy, Hadronization, Nuclear physics, Baryon, Rapidity, Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, NA49 experiment
Abstract

The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20$A$ GeV and 158$A$ GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on $p$, $\bar{p}$, $\Lambda$, $\bar{\Lambda}$, $\Xi^-$ and $\bar{\Xi}^+$ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the $m_t$ spectra on the collision energy and centrality, and the mass number of the produced nuclei $^3He$, $t$, $d$ and $\bar{d}$ are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable agreement between the measured yield for $^3He$ and those predicted by the statistical hadronization model. In addition, new results on $\Lambda$ and $\bar{\Lambda}$ as well as $\Xi^-$ production in minimum bias Pb+Pb reactions at 40$A$ GeV and 158$A$ GeV and central C+C, Si+Si and Pb+Pb collisions are presented. The system size dependence of the yields of these hyperons was analysed to determine the evolution of strangeness enhancement relative to elementary p+p collisions., Comment: Presented at Critical Point and Onset of Deconfinement 4th International Workshop, July 9-13 2007, GSI Darmstadt,Germany}

Published
2007

43. Event-by-event transverse momentum fluctuations in nuclear collisions at CERN SPS

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Białkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Bunčić, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csató, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gál, J., Gaździcki, M., Genchev, V., Georgopoulos, G., Gładysz, E., Grebieszkow, K., Hegyi, S., Höhne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V. I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., Leeuwen, M., Lévai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnár, J., Mrówczyński, St, Nicolic, V., Pálla, G., Panagiotou, A. D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Pühlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczyński, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Siklér, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Ströbele, H., Susa, T., Szentpétery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranić, D., Wetzler, A., Zbigniew Wlodarczyk, Wojtaszek, A., Yoo, I. K., and Zimány, J.

Subjects
Nuclear physics, Physics, Large Hadron Collider, Event (relativity), Transverse momentum, Nuclear Theory, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, Nuclear Physics
Abstract

The latest NA49 results on event-by-event transverse momentum fluctuations are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). Two different methods are applied: evaluating the $\Phi_{p_{T}}$ fluctuation measure and studying two-particle transverse momentum correlations. The obtained results are compared to predictions of the UrQMD model. The results on the energy dependence are compared to the NA49 data on the system size dependence. The NA61 (SHINE, NA49-future) strategy of searching of the QCD critical end-point is also discussed., Comment: proceedings article from CPOD07 (figure 7 - updated, reference 2 - modified)

Published
2007

44. Energy dependence of multiplicity fluctuations in heavy ion collisions

Author

Alt, Christopher, Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Białkowska, H., Blume, Christoph, Boimska, B., Botje, M., Bracinik, J., Bramm, R., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J. G., Csató, P., Dinkelaker, Peter, Eckard, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gál, J., Gazdzicki, Marek, Genchev, V., Georgopoulos, G., Gładysz, E., Grebieszkow, K., Hegyi, S., Höhne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R, Leeuwen, Marco van, Lévai, P., Litov, L., Lungwitz, Benjamin, Makariev, M., Malakhov, A. I., Mateev, M., Melkumov, G. L., Mischke, A., Mitrovski, M., Molnár, J., Mrówczynski, St., Nicolic, V., Nicolic, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Pühlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, Andres, Schmitz, N., Schuster, T., Seyboth, P., Siklér, F., Sitar, B., Skrzypczaki, E., Slodkowski, M., Stefanek, G., Stock, Reinhard, Strabel, C., Ströbele, Herbert, Susa, T., Szentpétery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G. I., Vesztergombi, G., Vranic, D., Wetzler, A., Włodarczyk, Z., Wojtaszek, A., Yoo, I. K., Zimányi, József, and Correlations and Fluctuations in Relativistic Nuclear Collisions July 7-9 2006 Florence, Italy

Subjects
Nuclear Theory, High Energy Physics::Experiment, ddc:530, Nuclear Experiment
Abstract

The energy dependence of multiplicity fluctuations was studied for the most central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV by the NA49 experiment at the CERN SPS. The multiplicity distribution for negatively and positively charged hadrons is significantly narrower than Poisson one for all energies. No significant structure in energy dependence of the scaled variance of multiplicity fluctuations is observed. The measured scaled variance is lower than the one predicted by the grand-canonical formulation of the hadron-resonance gas model. The results for scaled variance are in approximate agreement with the string-hadronic model UrQMD.

Published
2007

45. Inclusive production of charged pions in p+C collisions at 158 GeV/c beam momentum

Author

Alt, C. Baatar, B. Barna, D. Barr, G. Bartke, J. Betev, L. Białkowska, H. Blume, C. Boimska, B. Bracinik, J. Bramm, R. Bunčić, P. Cerny, V. Christakoglou, P. Chvala, O. Dinkelaker, P. Dolejsi, J. Eckardt, V. Fischer, H.G. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gaździcki, M. Georgopoulos, G. Höhne, C. Karev, A. Kniege, S. Kollegger, T. Kolesnikov, V.I. Kornas, E. Kowalski, M. Kraus, I. Kreps, M. Litov, L. Makariev, M. Malakhov, A.I. Mateev, M. Melkumov, G.L. Mitrovski, M. Pálla, G. Panagiotou, A.D. Panayotov, D. Pattison, C. Petridis, A. Renfordt, R. Rybicki, A. Sandoval, A. Schmitz, N. Seyboth, P. Siklér, F. Stock, R. Ströbele, H. Sziklai, J. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G.I. Vesztergombi, G. Vranić, D. Wenig, S. Wetzler, A. Zaranek, J.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

The production of charged pions in minimum bias p+C interactions is studied using a sample of 377000 inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.8 GeV/c in transverse momentum and from -0.1 to 0.5 in Feynman xF. Inclusive invariant cross sections are given on a grid of 270 bins per charge, thus offering for the first time a dense coverage of the projectile hemisphere and of the cross-over region into the target fragmentation zone. © 2007 Springer-Verlag.

Published
2007

46. Elliptic flow of Lambda hyperons in Pb+Pb collisions at 158A GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gal, J. Gazdzicki, M. and Georgopoulos, G. Gladysz, E. Grebieszkow, K. Hegyi, S. and Hoehne, C. Kadija, K. Karev, A. Kliemant, M. Kniege, S. and Kolesnikov, V. I. Kornas, E. Korus, R. Kowalski, M. and Kraus, I. Kreps, M. Lacey, R. Laszlo, A. van Leeuwen, M. and Levai, P. Litov, L. Lungwitz, B. Makariev, M. and Malakhov, A. I. Mateev, M. Melkumov, G. L. Mischke, A. and Mitrovski, M. Molnar, J. Mrowczynski, St. Nicolic, V. and Palla, G. Panagiotou, A. D. Panayotov, D. Petridis, A. and Pikna, M. Prindle, D. Puehlhofer, F. Renfordt, R. and Roland, C. Roland, G. Rybczynski, M. Rybicki, A. and Sandoval, A. Schmitz, N. Schuster, T. Seyboth, P. and Sikler, F. Sitar, B. Skrzypczak, E. Stefanek, G. Stock, R. Strabel, C. Stroebele, H. Susa, T. Szentpetery, I. and Sziklai, J. Szymanski, P. Trubnikov, V. Varga, D. and Vassiliou, M. Veres, G. I. Vesztergombi, G. Vranic, D. and Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. Yoo, I. K. and Zimanyi, J. NA49 Collaboration

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

The elliptic flow of Lambda hyperons has been measured by the NA49 Collaboration at the CERN-SPS in semicentral Pb+Pb collisions at 158A GeV. The standard method of correlating particles with the event plane was used. Measurements of v(2) near midrapidity are reported as a function of rapidity, centrality and transverse momentum. Elliptic flow of Lambda particles increases both with the impact parameter and with the transverse momentum. It is compared with v(2) for pions and protons as well as with model calculations. The observation of significant elliptic flow and its mass dependence suggest strong collective behavior of the matter produced in collisions of heavy nuclei already at the SPS. Scaling properties of elliptic flow of different particle species have been tested at 158A GeV. The limited p(T) range of the data does not allow for a decisive test of the coalescence model.

Published
2007

47. Centrality and system size dependence of multiplicity fluctuations in nuclear collisions at 158A GeV

Author

Alt, C. Anticic, T. Baatar, B. Barna, D. Bartke, J. and Betev, L. Bialkowska, H. Blume, C. Boimska, B. Botje, M. and Bracinik, J. Bramm, R. Buncic, P. Cerny, V. and Christakoglou, P. Chung, P. Chvala, O. Cramer, J. G. and Csato, P. Dinkelaker, P. Eckardt, V. Flierl, D. Fodor, Z. Foka, P. Friese, V. Gl, J. Gazdzicki, M. Genchev, V. Georgopoulos, G. Gladysz, E. Grebieszkow, K. Hegyi, S. Hoehne, C. Kadija, K. Karev, A. Kikola, D. and Kliemant, M. Kniege, S. Kolesnikov, V. I. Kornas, E. and Korus, R. Kowalski, M. Kraus, I. Kreps, M. Laszlo, A. and Lacey, R. van Leeuwen, M. Levai, P. Litov, L. and Lungwitz, B. Makariev, M. Malakhov, A. I. Mateev, M. and Melkumov, G. L. Mischke, A. Mitrovski, M. Molnar, J. and Mrowczynski, St. Nicolic, V. Palla, G. Panagiotou, A. D. and Panayotov, D. Peryt, W. Petridis, A. Pikna, M. Pluta, J. and Prindle, D. Puehlhofer, F. Renfordt, R. Roland, C. and Roland, G. Rybczynski, M. Rybicki, A. Sandoval, A. and Schmitz, N. Schuster, T. Seyboth, P. Sikler, F. Sitar, B. Skrzypczak, E. Slodkowski, M. Stefanek, G. Stock, R. and Strabel, C. Stroebele, H. Susa, T. Szentpetery, I. and Sziklai, J. Szuba, M. Szymanski, P. Trubnikov, V. Varga, D. Vassiliou, M. Veres, G. I. Vesztergombi, G. Vranic, D. Wetzler, A. Wlodarczyk, Z. Wojtaszek, A. Yoo, I. K. and Zimnyi, J. NA49 Collaboration

Subjects
Nuclear Experiment
Abstract

The centrality and system size dependence of multiplicity fluctuations of charged particles produced in nuclear collisions at 158A GeV was studied by the NA49 Collaboration. Centrality selected Pb+Pb collisions, semicentral C+C and Si+Si collisions as well as inelastic p+p interactions were analyzed. The number of projectile participants determined on an event-by-event basis was used to characterize the collision centrality. The scaled variance of the multiplicity distribution obtained in the forward rapidity region (1.1 < y(c.m.)< 2.6) shows a significant increase toward peripheral collisions. The results are similar for negatively and positively charged particles and about 50% larger for all charged particles. String-hadronic models of nuclear reactions without the fusion process do not reproduce the rise of fluctuations from central toward peripheral collisions. The measured centrality dependence can be reproduced in superposition models with the assumption of contributions from target participants to particle production in the forward hemisphere or in string models with fusion.

Published
2007

48. Pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kollegger, T., Kornas, E., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Yoo, I.K., and Zimanyi, J.

Subjects
Nuclear Theory, FOS: Physical sciences, Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. A rapid change of the energy dependence is observed around 30A GeV for the yields of pions and kaons as well as for the shape of the transverse mass spectra. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low SPS energies., Comment: 12 pages, 8 figures

Published
2007
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49. Rapidity and energy dependence of the electric charge correlations in A+A collisions at the SPS energies

Author

Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Lungwitz, B., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I.K., and Zimanyi, J.

Subjects
FOS: Physical sciences, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Results from electric charge correlations studied with the Balance Function method in A+A collisions from 20\emph{A} to 158\emph{A} GeV are presented in two different rapidity intervals: In the mid-rapidity region we observe a decrease of the width of the Balance Function distribution with increasing centrality of the collision, whereas this effect vanishes in the forward rapidity region. Results from the energy dependence study in central Pb+Pb collisions show that the narrowing of the Balance Function expressed by the normalised width parameter \textit{W} increases with energy towards the highest SPS and RHIC energies. Finally we compare our experimental data points with predictions of several models. The hadronic string models UrQMD and HIJING do not reproduce the observed narrowing of the Balance Function. However, AMPT which contains a quark-parton transport phase before hadronization can reproduce the narrowing of the BF's width with centrality. This confirms the proposed sensitivity of the Balance Function analysis to the time of hadronization., Comment: Submitted in Phys. Rev. C

Published
2007
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50. Energy, Rapidity and Transverse Momentum Dependence of Multiplicity Fluctuations in Heavy Ion Collisions at CERN SPS

Author

Lungwitz, Benjamin, Alt, C., Anticic, T., Baatar, B., Barna, D., Bartke, J., Betev, L., Bialkowska, H., Blume, C., Boimska, B., Botje, M., Bracinik, J., Bramm, R., Buncic, P., Cerny, V., Christakoglou, P., Chung, P., Chvala, O., Cramer, J.G., Csato, P., Dinkelaker, P., Eckardt, V., Flierl, D., Fodor, Z., Foka, P., Friese, V., Gal, J., Gazdzicki, M., Genchev, V., Georgopoulos, G., Gladysz, E., Grebieszkow, K., Hegyi, S., Hohne, C., Kadija, K., Karev, A., Kikola, D., Kliemant, M., Kniege, S., Kolesnikov, V.I., Kornas, E., Korus, R., Kowalski, M., Kraus, I., Kreps, M., Laszlo, A., Lacey, R., van Leeuwen, M., Levai, P., Litov, L., Makariev, M., Malakhov, A.I., Mateev, M., Melkumov, G.L., Mischke, A., Mitrovski, M., Molnar, J., Mrowczynski, St., Nicolic, V., Palla, G., Panagiotou, A.D., Panayotov, D., Petridis, A., Peryt, W., Pikna, M., Pluta, J., Prindle, D., Puhlhofer, F., Renfordt, R., Roland, C., Roland, G., Rybczynski, M., Rybicki, A., Sandoval, A., Schmitz, N., Schuster, T., Seyboth, P., Sikler, F., Sitar, B., Skrzypczak, E., Slodkowski, M., Stefanek, G., Stock, R., Strabel, C., Strobele, H., Susa, T., Szentpetery, I., Sziklai, J., Szuba, M., Szymanski, P., Trubnikov, V., Varga, D., Vassiliou, M., Veres, G.I., Vesztergombi, G., Vranic, D., Wetzler, A., Wlodarczyk, Z., Wojtaszek, A., Yoo, I.K., and Zimanyi, J.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, Nuclear Physics
Abstract

Multiplicity fluctuations in the forward hemisphere were studied for positively, negatively and all charged hadrons produced in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV. The multiplicity distributions and their scaled variances are presented as a function of collision energy, rapidity and transverse momentum. The distributions have a bell-like shape and the scaled variance changes monotonously with energy in the range from 0.8 to 1.2. No indication of the critical point is observed. The string-hadronic model UrQMD reproduces results on the scaled variance. The predictions of the hadron-resonance gas model obtained within the grand-canonical and canonical ensembles for the scaled variance disagree with the data., Comment: presented at Critical Point and Onset of Deconfinement, 4th International Workshop, July 9-13 2007, GSI Darmstadt, Germany, updated version including referee comments

Published
2007
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