22 research outputs found

    Measurements of elliptic and triangular flow in high-multiplicity 3^{3}He++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    We present the first measurement of elliptic (v2v_2) and triangular (v3v_3) flow in high-multiplicity 3^{3}He++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3^{3}He++Au and in pp++pp collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3^{3}He++Au system. The collective behavior is quantified in terms of elliptic v2v_2 and triangular v3v_3 anisotropy coefficients measured with respect to their corresponding event planes. The v2v_2 values are comparable to those previously measured in dd++Au collisions at the same nucleon-nucleon center-of-mass energy. Comparison with various theoretical predictions are made, including to models where the hot spots created by the impact of the three 3^{3}He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.Comment: 630 authors, 9 pages, 4 figures, 2 tables. v2 is the version accepted for publication by Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Transverse energy production and charged-particle multiplicity at midrapidity in various systems from sNN=7.7\sqrt{s_{NN}}=7.7 to 200 GeV

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    Measurements of midrapidity charged particle multiplicity distributions, dNch/dηdN_{\rm ch}/d\eta, and midrapidity transverse-energy distributions, dET/dηdE_T/d\eta, are presented for a variety of collision systems and energies. Included are distributions for Au++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu++Cu collisions at sNN=200\sqrt{s_{_{NN}}}=200 and 62.4 GeV, Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV, U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV, dd++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV, 3^{3}He++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV, and pp++pp collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, NpartN_{\rm part}, and the number of constituent quark participants, NqpN_{q{\rm p}}. For all AA++AA collisions down to sNN=7.7\sqrt{s_{_{NN}}}=7.7 GeV, it is observed that the midrapidity data are better described by scaling with NqpN_{q{\rm p}} than scaling with NpartN_{\rm part}. Also presented are estimates of the Bjorken energy density, εBJ\varepsilon_{\rm BJ}, and the ratio of dET/dηdE_T/d\eta to dNch/dηdN_{\rm ch}/d\eta, the latter of which is seen to be constant as a function of centrality for all systems.Comment: 706 authors, 32 pages, 20 figures, 34 tables, 2004, 2005, 2008, 2010, 2011, and 2012 data. v2 is version accepted for publication in Phys. Rev.

    Measurements of identified particle anisotropic flow in Cu plus Au and U plus U collisions by PHENIX experiment

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    Measurement of KS0K_S^0 and K0K^{*0} in pp++pp, dd++Au, and Cu++Cu collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of KS0K_S^0 and K0K^{*0} meson production at midrapidity in pp++pp, dd++Au, and Cu++Cu collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. The KS0K_S^0 and K0K^{*0} mesons are reconstructed via their KS0π0(γγ)π0(γγ)K_S^0 \rightarrow \pi^0(\rightarrow \gamma\gamma)\pi^0(\rightarrow\gamma\gamma) and K0K±πK^{*0} \rightarrow K^{\pm}\pi^{\mp} decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of KS0K_S^0 and K0K^{*0} mesons in dd++Au and Cu++Cu collisions at different centralities. In the dd++Au collisions, the nuclear modification factor of KS0K_S^0 and K0K^{*0} mesons is almost constant as a function of transverse momentum and is consistent with unity showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu++Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the pp++pp yield scaled by the number of binary nucleon-nucleon collisions in the Cu++Cu system. In the pTp_T range 2--5 GeV/cc, the strange mesons (KS0K_S^0, K0K^{*0}) similarly to the ϕ\phi meson with hidden strangeness, show an intermediate suppression between the more suppressed light quark mesons (π0\pi^0) and the nonsuppressed baryons (pp, pˉ\bar{p}). At higher transverse momentum, pT>5p_T>5 GeV/cc, production of all particles is similarly suppressed by a factor of \approx 2.Comment: 590 authors, 22 pages, 14 figures, 5 tables. Submitted to Phys. Rev. C Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Spectroscopic Flow Evaluation in Inductively Coupled Plasma Wind Tunnel

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    8th Edition Tumor, Node, and Metastasis T-Stage Prognosis Discrepancies: Solid Component Diameter Predicts Prognosis Better than Invasive Component Diameter

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    The biggest change in the 8th edition of the tumor, lymph node, and metastasis (TNM) classification is the recommendation of the solid component diameter and invasive size for determining the clinical and pathological T-factor, respectively. Here, we validated new proposals for the Lung Cancer TNM classification’s revision and compared clinical and pathological T-stages. We retrospectively analyzed 177 cases of non-small cell lung cancers without lymph node metastasis, and involving complete resection, that occurred in our department between January 2017 and March 2019. We reviewed the overall tumor diameter, solid component diameter, and clinical T-factor on computed tomography (CT), and the pathological tumor diameter, pathological invasion diameter, pathological T-factor, and prognosis. The difference between the pathological invasive size and solid size on CT was within 5 mm in 99 cases (56%). At a two-year recurrence-free survival rate, the clinical T-stage demonstrated a better prognostic outcome than the pathological T-stage. Despite including the benign findings, the solid component diameter was better correlated with prognosis than the invasive size. Therefore, in cases of discrepancies of clinically and pathologically detected tumor size, the solid CT size should also be used for the pathological T classification
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