6,243 research outputs found

    Quarkonium Results in PbPb Collisions at CMS

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    We summarize the results from the study of charmonium and bottomonium via the dimuon decay channel in PbPb collisions with the CMS experiment. We discuss the observation of sequential suppression of the Upsilon states. We present preliminary results of prompt J/psi and psi' production, as well as of non-prompt J/psis coming from the weak decay of b-quarks. This latter measurement is sensitive to b-quark energy loss. We discuss the results and compare to model predictions.Comment: 8 pages, 4 figures. Proceedings of 29th Winter Workshop on Nuclear Dynamic

    Study of The Corrosion Processes On Roman And Byzantine Glasses From Northern Tunisia

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    The present investigation focuses on some glass objects among those discovered in an area around the ancient city of Thugga in northern Tunisia, particularly flourishing during the Roman and Byzantine periods (1). The Late Roman-Byzantine time is not characterised by elaborate vessel shapes derived from precious metal prototypes, but rather by simpler multifunctional forms, as beakers, goblets, and dishes with similar features in the whole Mediterranean world. Also the glass composition seems to change between the 4th and the 5th century, turning to a yellowish-green or olive green colouration of the glass instead of the typical Roman blue-greenish colouration of earlier times. This new glass colouration varies further drastically in the 7th century, when a characteristic light blue-turquoise glass becomes the most widespread. A complete chemical characterization of these objects was carried out in a previous study (2) aimed to investigate the production technology including the chromophores responsible for the different shades. In the present work we have investigated the degradation and corrosion processes affecting some of these shards. It is worth to note that to ascertain the composition of the glass surfaces the analyses have been carried out by means of non-destructive techniques such as XPS (X-ray photoelectron spectroscopy), SEM-EDX (scanning electron microscopy coupled with energy dispersive X-ray analysis) and laser-ablation ICP-MS ((Inductively Coupled Plasma \u2013 Mass Spectrometry)

    STAR Results on High Transverse Momentum, Heavy Flavor and Electromagnetic Probes

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    We summarize here recent results from the STAR collaboration focusing on processes involving large momentum transfers. Measurements of angular correlations of di-hadrons are explored in both the pseudorapidity (eta) and azimuthal (phi) projections. In central Au+Au, an elongated structure is found in the eta projection which persists up to the highest measured pT. After quantifying the particle yield in this structure and subtracting it from the near-side yield, we observe that the remainder exhibits a behavior strikingly similar to that of the near-side yield in d+Au. For heavy flavor production, using electron-hadron correlations in p+p collisions, we obtain an estimate of the b-quark contribution to the non-photonic electrons in the pT region 3-6 GeV/c, and find it consistent with FONLL calculations. Together with the observed suppression of non-photonic electrons in Au+Au, this strongly suggests suppression of b-quark production in Au+Au collisions. We discuss results on the mid-rapidity Upsilon cross-section in p+p collisions. Finally, we present a proof-of-principle measurement of photon-hadron correlations in p+p collisions, paving the way for the tomographic study of the matter produced in central Au+Au via gamma-jet measurements.Comment: 8 pages, 4 figures. Proceedings of "Quark Matter 2006", 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collision

    Archaeometric approach for the study of mortars from the underwater archaeological site of Baia (Naples) Italy: Preliminary results

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    This work was aimed to evaluate the features of mortar samples taken from the underwater archaeological area of Baia (Naples, Italy), an important site, where the remains of the ancient Roman city of Baiae and Portus Iulius are submerged after bradyseism events, started from 4th century AD. Several architectural structures are still preserved into the submerged environment, such as: luxurious maritime villas, imperial buildings, private houses, thermae, tabernae and warehouses. In particular, some samples were collected from the masonry walls belonging to a building of the underwater area called Villa a Protiro. A first archaeometric approach has been applied to analyse twelve archaeological mortars samples in order to define: textural features, chemical composition and raw materials used for their production. For this purpose different analytical methods were used, such as, polarizing optical microscope (POM) and scanning electron microscopy (SEM-EDS).This work was financially supported by national national research project “COMAS” (Planned COnservation, “in situ”, of underwater archaeological artifacts), funded by the Italian Ministry of Education, Universities and Research (MIUR).Peer reviewe

    The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC

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    The STAR Time Projection Chamber (TPC) is used to record collisions at the Relativistic Heavy Ion Collider (RHIC). The TPC is the central element in a suite of detectors that surrounds the interaction vertex. The TPC provides complete coverage around the beam-line, and provides complete tracking for charged particles within +- 1.8 units of pseudo-rapidity of the center-of-mass frame. Charged particles with momenta greater than 100 MeV/c are recorded. Multiplicities in excess of 3,000 tracks per event are routinely reconstructed in the software. The TPC measures 4 m in diameter by 4.2 m long, making it the largest TPC in the world.Comment: 28 pages, 11 figure

    Composición nutricional de nuevas variedades de cacahuate (Arachis Hypogaea L.)

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    Six peanut (Arachis hypogaea L.) cultivars (Col-24-Gro, Col-61-Gto, VA-81-B, Ranferi Díaz, NC-2 and Florunner) were studied for agricultural yield, chemical composition (protein, fat, carbohydrates, fiber and ash), amino acid profile, digestibility, fatty acid profile, tocopherol and sterol contents. Results indicated that Ranferi Díaz and Col-61-Gto presented the highest yield (6.3 Ton/ha). Protein content was from 23.5 to 26.6% and fat content ranged from 49.8-53.4%. Mean digestibility was 86%. Lysine and threonine levels in all cultivars were sufficient to meet human requirements. Total saturated fatty acids ranged from 15-18%. The oleic/linoleic ratio was estimated 1.3-1.4. Tocopherol levels varied from 390 to 706 ppm. The highest tocopherol levels corresponded to the cultivars with the lowest yield. The alpha tocopherol content was estimated at 90-150 ppm, while gamma tocopherol was 270-570 ppm.The main sterol present was βsitosterol (approx. 65%). Ranferi Diaz variety presented the highest agronomic yield and the highest protein content but low oleic acid, low sterols and low total tocopherols. The differences among cultivars suggest differences in their applications.Se estudio el rendimiento agrícola y composición química (proteína, grasa, carbohidratos, fibra y cenizas), perfil de amino ácidos, digestibilidad, perfil de ácidos grasos, contenido de tocoferol y de esteroles de seis variedades de cacahuate (Arachis hypogaea L.) Col-24-Gro, Col-61-Gto, VA-81B, Ranferi Díaz, NC-2 y Florunner. Los resultados mostraron que el mayor rendimiento se logró en las variedades Ranferi Díaz y Col-61-Gto (6.3 Ton/ha). El contenido de proteína fue de 23.5 a 26.6% y el contenido de grasa en un intervalo de 49.8 a 53.4%. La digestibilidad promedio de las seis variedades fue de 86%. El contenido de lisina y treonina en la proteína de todas las variedades fue suficiente para satisfacer los requerimientos del humano. La composición del aceite de las diferentes variedades de cacahuate se caracterizó por contener de 15-18% de ácidos grasos saturados. La relación oleico/linoleico fue de 1.3-1.4. El contenido de tocoferoles totales fue entre 390 a 706 ppm. El mayor contenido de tocoferol correspondió a las variedades con los rendimientos más bajos. Con respecto al contenido de alfa tocoferol se encontró entre 90-150 ppm y el gamma tocoferol fue entre 270570 ppm. El contenido de beta-sitosterol fue similar en las seis variedades (aprox. 65%). La variedad Ranferi Diaz presentó el más alto rendimiento agronómico y el más alto contenido de proteína. Sin embargo, esta variedad presento el más bajo contenido de ácido oleico, bajo contenido de esteroles y bajo contenido de tocoferoles totales. Estas diferencias entre las variedades de cacahuate sugieren que cada una de ellas deberá tener diferente uso como alimento

    Molecular rearrangements in extrusion processes for the production of amaranth-enriched, gluten-free rice pasta

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    Gluten-free pasta represents a challenge for food technologists and nutritionists since gluten-free materials used in conventional formulations have poor functional and nutritional properties. A novel extrusion-cooking process was set up to improve the textural characteristics of rice-based pasta, and to enrich it with amaranth. Mineral and fiber content, and protein digestibility were improved by amaranth enrichment. Extrusion-cooking of a 75/25 mixture of rice flour and amaranth prior to pasta-making gave the best results as for the textural characteristics of the final product. The firmness of cooked pasta increased due to the extrusion-cooking process, that also decreased protein solubility in the amaranth-enriched pasta. The content in accessible thiols also decreased in amaranth-enriched pastas, indicating that amaranth proteins may be involved in forming disulphide bonds during the pasta-making process. Our results suggest that starch in rice flour interacts best with amaranth proteins when starch gelatinization occurs simultaneously to protein denaturation in the extrusion-cooking proces

    Azimuthal anisotropy and correlations in the hard scattering regime at RHIC

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    Azimuthal anisotropy (v2v_2) and two-particle angular correlations of high pTp_T charged hadrons have been measured in Au+Au collisions at sNN\sqrt{s_{NN}}=130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected to contribute significantly. The two-particle angular correlations exhibit elliptic flow and a structure suggestive of fragmentation of high pTp_T partons. The monotonic rise of v2(pT)v_2(p_T) for pT<2p_T<2 GeV/c is consistent with collective hydrodynamical flow calculations. At \pT>3 GeV/c a saturation of v2v_2 is observed which persists up to pT=6p_T=6 GeV/c.Comment: As publishe

    Disappearance of back-to-back high pTp_T hadron correlations in central Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV

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    Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at sNN\sqrt{s_{NN}} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.Comment: submitted to Phys. Rev. Let

    Azimuthal anisotropy of K0S and Lambda + Lambda -bar production at midrapidity from Au+Au collisions at sqrt[sNN]=130 GeV

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    We report STAR results on the azimuthal anisotropy parameter v2 for strange particles K0S, Lambda , and Lambda -bar at midrapidity in Au+Au collisions at sqrt[sNN]=130 GeV at the Relativistic Heavy Ion Collider. The value of v2 as a function of transverse momentum, pt, of the produced particle and collision centrality is presented for both particles up to pt~3.0 GeV/c. A strong pt dependence in v2 is observed up to 2.0 GeV/c. The v2 measurement is compared with hydrodynamic model calculations. The physics implications of the pt integrated v2 magnitude as a function of particle mass are also discussed.Alle Autoren: C. Adler, Z. Ahammed, C. Allgower, J. Amonett, B. D. Anderson, M. Anderson, G. S. Averichev, J. Balewski, O. Barannikova, L. S. Barnby, J. Baudot, S. Bekele, V. V. Belaga, R. Bellwied, J. Berger, H. Bichsel, A. Billmeier, L. C. Bland, C. O. Blyth, B. E. Bonner, A. Boucham, A. Brandin, A. Bravar, R. V. Cadman, H. Caines, M. Calderón de la Barca Sánchez, A. Cardenas, J. Carroll, J. Castillo, M. Castro, D. Cebra, P. Chaloupka, S. Chattopadhyay, Y. Chen, S. P. Chernenko, M. Cherney, A. Chikanian, B. Choi, W. Christie, J. P. Coffin, T. M. Cormier, J. G. Cramer, H. J. Crawford, W. S. Deng, A. A. Derevschikov, L. Didenko, T. Dietel, J. E. Draper, V. B. Dunin, J. C. Dunlop, V. Eckardt, L. G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, P. Fachini, V. Faine, K. Filimonov, E. Finch, Y. Fisyak, D. Flierl, K. J. Foley, J. Fu, C. A. Gagliardi, N. Gagunashvili, J. Gans, L. Gaudichet, M. Germain, F. Geurts, V. Ghazikhanian, O. Grachov, V. Grigoriev, M. Guedon, E. Gushin, T. J. Hallman, D. Hardtke, J. W. Harris, T. W. Henry, S. Heppelmann, T. Herston, B. Hippolyte, A. Hirsch, E. Hjort, G. W. Hoffmann, M. Horsley, H. Z. Huang, T. J. Humanic, G. Igo, A. Ishihara, Yu. I. Ivanshin, P. Jacobs, W. W. Jacobs, M. Janik, I. Johnson, P. G. Jones, E. G. Judd, M. Kaneta, M. Kaplan, D. Keane, J. Kiryluk, A. Kisiel, J. Klay, S. R. Klein, A. Klyachko, A. S. Konstantinov, M. Kopytine, L. Kotchenda, A. D. Kovalenko, M. Kramer, P. Kravtsov, K. Krueger, C. Kuhn, A. I. Kulikov, G. J. Kunde, C. L. Kunz, R. Kh. Kutuev, A. A. Kuznetsov, L. Lakehal-Ayat, M. A. C. Lamont, J. M. Landgraf, S. Lange, C. P. Lansdell, B. Lasiuk, F. Laue, A. Lebedev, R. Lednický, V. M. Leontiev, M. J. LeVine, Q. Li, S. J. Lindenbaum, M. A. Lisa, F. Liu, L. Liu, Z. Liu, Q. J. Liu, T. Ljubicic, W. J. Llope, G. LoCurto, H. Long, R. S. Longacre, M. Lopez-Noriega, W. A. Love, T. Ludlam, D. Lynn, J. Ma, R. Majka, S. Margetis, C. Markert, L. Martin, J. Marx, H. S. Matis, Yu. A. Matulenko, T. S. McShane, F. Meissner, Yu. Melnick, A. Meschanin, M. Messer, M. L. Miller, Z. Milosevich, N. G. Minaev, J. Mitchell, V. A. Moiseenko, C. F. Moore, V. Morozov, M. M. de Moura, M. G. Munhoz, J. M. Nelson, P. Nevski, V. A. Nikitin, L. V. Nogach, B. Norman, S. B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, G. Paic, S. U. Pandey, Y. Panebratsev, S. Y. Panitkin, A. I. Pavlinov, T. Pawlak, V. Perevoztchikov, W. Peryt, V. A Petrov, M. Planinic, J. Pluta, N. Porile, J. Porter, A. M. Poskanzer, E. Potrebenikova, D. Prindle, C. Pruneau, J. Putschke, G. Rai, G. Rakness, O. Ravel, R. L. Ray, S. V. Razin, D. Reichhold, J. G. Reid, F. Retiere, A. Ridiger, H. G. Ritter, J. B. Roberts, O. V. Rogachevski, J. L. Romero, A. Rose, C. Roy, V. Rykov, I. Sakrejda, S. Salur, J. Sandweiss, A. C. Saulys, I. Savin, J. Schambach, R. P. Scharenberg, N. Schmitz, L. S. Schroeder, A. Schüttauf, K. Schweda, J. Seger, D. Seliverstov, P. Seyboth, E. Shahaliev, K. E. Shestermanov, S. S. Shimanskii, V. S. Shvetcov, G. Skoro, N. Smirnov, R. Snellings, P. Sorensen, J. Sowinski, H. M. Spinka, B. Srivastava, E. J. Stephenson, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, C. Struck, A. A. P. Suaide, E. Sugarbaker, C. Suire, M. Šumbera, B. Surrow, T. J. M. Symons, A. Szanto de Toledo, P. Szarwas, A. Tai, J. Takahashi, A. H. Tang, J. H. Thomas, M. Thompson, V. Tikhomirov, M. Tokarev, M. B. Tonjes, T. A. Trainor, S. Trentalange, R. E. Tribble, V. Trofimov, O. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, A. M. VanderMolen, I. M. Vasilevski, A. N. Vasiliev, S. E. Vigdor, S. A. Voloshin, F. Wang, H. Ward, J. W. Watson, R. Wells, G. D. Westfall, C. Whitten, Jr., H. Wieman, R. Willson, S. W. Wissink, R. Witt, J. Wood, N. Xu, Z. Xu, A. E. Yakutin, E. Yamamoto, J. Yang, P. Yepes, V. I. Yurevich, Y. V. Zanevski, I. Zborovský, H. Zhang, W. M. Zhang, R. Zoulkarneev, and A. N. Zubarev (STAR Collaboration
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