194 research outputs found

    Centrality dependence of the N(Ω)/N(ϕ)N(\Omega)/N(\phi) ratios and ϕ\phi v2v_{2} - a test of thermalization in Au+Au collisions at RHIC

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    We present the centrality dependence of the N(Ω)/N(ϕ)N(\Omega)/N(\phi) ratios and ϕ\phi v2v_{2} measured in Au+Au collisions at sNN=200\sqrt{s_{NN}}=200 GeV by the STAR experiment at RHIC. The results are compared to measurements of other identified particles and recombination model expectations in order to gain insight into the partonic collectivity and possible thermalization of the produced medium.Comment: 4 pages, 2 figures, Quark Matter 2006 conference proceeding

    Phi-meson Production in Heavy-Ion Collisions at RHIC

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    We present the first elliptic flow, v2v_{2}, measurement for the ϕ\phi-meson in Au+Au collisions at sNN\sqrt{s_{NN}}=200 GeV. At low pTp_{T} (<2 GeV/c), the v2v_{2} is consistent with mass ordering expected from hydrodynamics, while at higher pTp_{T} (>4 GeV/c), it follows the same trend as the KS0K^{0}_{S} v2v_{2} and a parameterization for number of quarks = 2. The nuclear modification factor, RCPR_{CP}, has also been measured and it follows the same trend as the KS0K^{0}_{S} rather than the Λ\Lambda which confirms the baryon/meson-type dependence of RCPR_{CP} at RHIC. A model based on the recombination of thermal s-quarks describes the central ϕ\phi-meson pTp_{T} spectrum as well as the baryon/meson ratio of Ω/ϕ\Omega/\phi up to pTp_{T} ~4 GeV/c.Comment: Submitted to J. Phys. G (Proceedings of the 9th International Conference on Strangeness in Quark Matter, Los Angeles, USA, March 26-31) 4 pages, 3 figure

    On the homomorphism order of labeled posets

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    Partially ordered sets labeled with k labels (k-posets) and their homomorphisms are examined. We give a representation of directed graphs by k-posets; this provides a new proof of the universality of the homomorphism order of k-posets. This universal order is a distributive lattice. We investigate some other properties, namely the infinite distributivity, the computation of infinite suprema and infima, and the complexity of certain decision problems involving the homomorphism order of k-posets. Sublattices are also examined.Comment: 14 page

    Improved Measurements of Partial Rate Asymmetry in B -> h h Decays

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    We report improved measurements of the partial rate asymmetry (Acp) in B -> h h decays with 140fb^-1 of data collected with the Belle detector at the KEKB e+e- collider. Here h stands for a charged or neutral pion or kaon and in total five decay modes are included: K-+ pi+-, K0s pi-+, K-+ pi0, pi-+ pi0 and K0s pi0. The flavor of the last decay mode is determined from the accompanying B meson. Using a data sample 4.7 times larger than that of our previous measurement, we find Acp(K-+ pi+-) -0.088+-0.035+-0.013, 2.4 sigma from zero. Results for other decay modes are also presented.Comment: 9 pages, 1 figur

    Role of thoracic ultrasonography in pleurodesis pathways for malignant pleural effusions (SIMPLE): an open-label, randomised controlled trial

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    BACKGROUND: Pleurodesis is done as an in-patient procedure to control symptomatic recurrent malignant pleural effusion (MPE) and has a success rate of 75-80%. Thoracic ultrasonography has been shown in a small study to predict pleurodesis success early by demonstrating cessation of lung sliding (a normal sign seen in healthy patients, lung sliding indicates normal movement of the lung inside the thorax). We aimed to investigate whether the use of thoracic ultrasonography in pleurodesis pathways could shorten hospital stay in patients with MPE undergoing pleurodesis. METHODS: The Efficacy of Sonographic and Biological Pleurodesis Indicators of Malignant Pleural Effusion (SIMPLE) trial was an open-label, randomised controlled trial done in ten respiratory centres in the UK and one respiratory centre in the Netherlands. Adult patients (aged ≥18 years) with confirmed MPE who required talc pleurodesis via either a chest tube or as poudrage during medical thorascopy were eligible. Patients were randomly assigned (1:1) to thoracic ultrasonography-guided care or standard care via an online platform using a minimisation algorithm. In the intervention group, daily thoracic ultrasonography examination for lung sliding in nine regions was done to derive an adherence score: present (1 point), questionable (2 points), or absent (3 points), with a lowest possible score of 9 (preserved sliding) and a highest possible score of 27 (complete absence of sliding); the chest tube was removed if the score was more than 20. In the standard care group, tube removal was based on daily output volume (per British Thoracic Society Guidelines). The primary outcome was length of hospital stay, and secondary outcomes were pleurodesis failure at 3 months, time to tube removal, all-cause mortality, symptoms and quality-of-life scores, and cost-effectiveness of thoracic ultrasonography-guided care. All outcomes were assessed in the modified intention-to-treat population (patients with missing data excluded), and a non-inferiority analysis of pleurodesis failure was done in the per-protocol population. This trial was registered with ISRCTN, ISRCTN16441661. FINDINGS: Between Dec 31, 2015, and Dec 17, 2019, 778 patients were assessed for eligibility and 313 participants (165 [53%] male) were recruited and randomly assigned to thoracic ultrasonography-guided care (n=159) or standard care (n=154). In the modified intention-to-treat population, the median length of hospital stay was significantly shorter in the intervention group (2 days [IQR 2-4]) than in the standard care group (3 days [2-5]; difference 1 day [95% CI 1-1]; p<0·0001). In the per-protocol analysis, thoracic ultrasonography-guided care was non-inferior to standard care in terms of pleurodesis failure at 3 months, which occurred in 27 (29·7%) of 91 patients in the intervention group versus 34 (31·2%) of 109 patients in the standard care group (risk difference -1·5% [95% CI -10·2% to 7·2%]; non-inferiority margin 15%). Mean time to chest tube removal in the intervention group was 2·4 days (SD 2·5) versus 3·1 days (2·0) in the standard care group (mean difference -0·72 days [95% CI -1·22 to -0·21]; p=0·0057). There were no significant between-group differences in all-cause mortality, symptom scores, or quality-of-life scores, except on the EQ-5D visual analogue scale, which was significantly lower in the standard care group at 3 months. Although costs were similar between the groups, thoracic ultrasonography-guided care was cost-effective compared with standard care. INTERPRETATION: Thoracic ultrasonography-guided care for pleurodesis in patients with MPE results in shorter hospital stay (compared with the British Thoracic Society recommendation for pleurodesis) without reducing the success rate of the procedure at 3 months. The data support consideration of standard use of thoracic ultrasonography in patients undergoing MPE-related pleurodesis. FUNDING: Marie Curie Cancer Care Committee

    Search for CP violation in the decay B0->D*+-D-+

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    We report a search for CP-violating asymmetry in B0 -> D*+- D-+ decays. The analysis employs two methods of B0 reconstruction: full and partial. In the full reconstruction method all daughter particles of the B0 are required to be detected; the partial reconstruction technique requires a fully reconstructed D- and only a slow pion from the D*+ -> D0 pi_slow+ decay. From a fit to the distribution of the time interval corresponding to the distance between two B meson decay points we calculate the CP-violating parameters and find the significance of nonzero CP asymmetry to be 2.7 standard deviations.Comment: 4 pages, 3 figure

    Set optimization - a rather short introduction

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    Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems

    Azimuthal anisotropy and correlations at large transverse momenta in p+pp+p and Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV

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    Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in p+pp+p at the same energy. Elliptic anisotropy, v2v_2, is found to reach its maximum at pt3p_t \sim 3 GeV/c, then decrease slowly and remain significant up to pt7p_t\approx 7 -- 10 GeV/c. Stronger suppression is found in the back-to-back high-ptp_t particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of v2v_2 at intermediate ptp_t is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004

    Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

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    The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape
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