Transmogrifying Fuzzy Vortices

We show that the construction of vortex solitons of the noncommutative Abelian-Higgs model can be extended to a critically coupled gauged linear sigma model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an explicit construction of the degree$-k$ static semilocal vortex and study in some detail the infinite coupling limit in which it descends to a degree$-k$ \C\Pk^{N} instanton. This relation between the fuzzy vortex and noncommutative lump is used to suggest an interpretation of the noncommutative sigma model soliton as tilted D-strings stretched between an NS5-brane and a stack of D3-branes in type IIB superstring theory.Comment: 21 pages, 4 figures, LaTeX(JHEP3

Energy and system size dependence of \phi meson production in Cu+Cu and Au+Au collisions

We study the beam-energy and system-size dependence of \phi meson production (using the hadronic decay mode \phi -- K+K-) by comparing the new results from Cu+Cu collisions and previously reported Au+Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from mid-rapidity (|y|<0.5) for 0.4 < pT < 5 GeV/c. At a given beam energy, the transverse momentum distributions for \phi mesons are observed to be similar in yield and shape for Cu+Cu and Au+Au colliding systems with similar average numbers of participating nucleons. The \phi meson yields in nucleus-nucleus collisions, normalised by the average number of participating nucleons, are found to be enhanced relative to those from p+p collisions with a different trend compared to strange baryons. The enhancement for \phi mesons is observed to be higher at \sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations for the produced \phi(s\bar{s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.Comment: 20 pages and 5 figure

Propagação in vitro de Baptistonia pubes (Lindl.) Chiron & V.P. Castro (Oncidium pubes Lindl.) (Orchidaceae) Propagation in vitro of Baptistonia pubes (Lindl.) Chiron & V.P. Castro (Oncidium pubes Lindl. - Orchidaceae)

Baptistonia pubes é uma epífita que ocorre na Floresta Atlântica do Brasil, no Paraguai e norte da Argentina. É considerada espécie vulnerável e ameaçada de extinção. Nossos objetivos foram avaliar a eficácia da germinação de suas sementes e o crescimento em dois pHs utilizando-se dois meios de cultura: Murashige-Skoog (modificado - (MS)) e meio nutritivo à base de banana nanica acrescido de NPK 20-20-20 (Plant Prood®) (BAN) variando-se as concentrações de nutrientes e pH para a germinação e para o crescimento inicial das plântulas. As sementes germinaram em média 15 dias após a inoculação, em todas as condições. A porcentagem de germinação variou entre 2,6 a 11,6%, sendo que a maior porcentagem ocorreu no pH=5,2 BAN e a menor no pH=6,2 MS/2. O meio BAN foi mais eficiente na germinação. Os pHs, em cada meio, alteraram significativamente as médias das sementes germinadas. As plântulas cresceram mais no meio nutritivo à base de banana nanica no pH = 5,2.<br>Baptistonia pubes is an epiphyte that grows in Brazilian Atlantic Forest, in Paraguay and northern Argentina. It is considered vulnerable and threatened with extinction. Our aim was to verify seed germination efficiency and growth at two pHs, using two culture mediums: Murashige-Skoog (modified - (MS)) and banana pulp with added NPK 20-20-20 (Plant Prood®) (BAN), with varied nutrient and pH concentrations for germination and for growth. The seeds germinated on average 15 days after the inoculation, at all conditions. The percentage of germination varied between 2.6 and 11.6 %. The highest percentage was at pH=5.2 BAN and the lowest at pH=6.2 MS/2. The banana pulp was most efficient for germination. The pHs, in each environment, altered significantly the averages of the germinated seeds. Seedling growth showed better results in the banana medium, pH = 5.