7 research outputs found

    Collision centrality and energy dependence of strange hadron production in Au + Au collisions at \sqrt{s_{NN}}= 7.7-54.4 GeV

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    We apply an equal-velocity quark combination model to systematically study the transverse momentum (p_{T}) spectra of strange hadrons K_{S}^{0}, \phi, \Lambda, \Xi^{-}, \Omega^{-}, \bar{\Lambda}, \bar{\Xi}^{+} and \bar{\Omega}^{+} at mid-rapidity in Au+Au collisions at \sqrt{s_{NN}}= 7.7, 11.5, 19.6, 27, 39, 54.4 GeV. Relative deviation between the model calculation and experimental data of these eight hadrons is generally about 2-3% at \sqrt{s_{NN}}= 27, 39, 54.4 GeV and in central collisions at 7.7, 11.5, 19.6 GeV. The deviation slightly increases up to about 4% in the semi-central and peripheral collision at \sqrt{s_{NN}}= 7.7, 11.5, 19.6 GeV. We systematically explain the dependence of two baryon-to-meson ratios \bar{\Lambda}/K_{S}^{0} and \Omega/\phi on p_{T}, collision centrality and collision energy by the property of quark p_{T} spectra at hadronization. We derive the analytic relations between R_{CP} of hadrons and those of quarks, and we use them to naturally explain the species and p_{T} dependence of R_{CP} of those strange hadrons

    Production of X

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    We investigate the production of Xb in the process Ī„(5S,6S)ā†’Ī³Xb, where Xb is assumed to be the counterpart of X(3872) in the bottomonium sector as BBĀÆāŽ molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for Ī„(5S,6S)ā†’Ī³Xb are orders of 10-5 with reasonable cutoff parameter range Ī±ā‰ƒ2~3. The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state Xb

    Energy Dependence of the Breit-Wheeler process in Heavy-Ion Collisions and its Application to Nuclear Charge Radius Measurements

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    The energy dependence of the cross section and the transverse momentum distribution of dielectrons from the Breit-Wheeler process in heavy-ion collisions are computed in the lowest-order QED and found to be sensitive to the nuclear charge distribution and the infrared-divergence of the ultra-Lorentz boosted Coulomb field. Within a given experimental kinematic acceptance, the cross section is found to increase while the pair average transverse momentum decreases with increasing beam energy. We demonstrate that the transverse-momentum component of Weizs\"acker-Williams photons is due to the finite extent of the charge source and electric field component in the longitudinal direction. We further clarify the connection between the nuclear charge distribution and the kinematics of produced e+eāˆ’e^+e^- from the Breit-Wheeler process, and propose a criterion for the validity of the Breit-Wheeler process in relativistic heavy-ion collisions. Following this approach we demonstrate that the experimental measurements of the Breit-Wheeler process in ultra-relativistic heavy-ion collisions can be used to quantitatively constrain the nuclear charge radius. The extracted parameters show potential centrality dependence, and can be used to study the initial charge fluctuation and final-state magnetic field effect in hadronic interactions.Comment: 3 figure

    Modeling and Analysis of Material Flows in Re-Entrant Supply Chain Networks Using Modified Partial Differential Equations

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    The basic partial differential equation (PDE) models for supply chain networks with re-entrant nodes and their macroscopic are proposed. However, through numerical examples, the basic continuum models do not perform well for multiple re-entrant systems. Then, a new state equation considering the re-entrant degree of the products is introduced to improve the effectiveness of the basic continuum models. The applicability of the modified continuum models for re-entrant supply chains is illustrated through numerical examples. Finally, based on the modified continuum model, numerical examples of different re-entrant degrees are given, meanwhile, the changes in the WIP and outflux are analyzed in details for multiple re-entrant supply chain systems

    ā€œBlock and attackā€ strategy for tumor therapy through ZnO2/siRNA/NIRā€mediating Zn2+ā€overload and amplified oxidative stress

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    Abstract Intracellular zinc ion (Zn2+) accumulation disrupts the Zn2+ homeostasis, providing an ionā€overloading anticancer strategy with great potential. The selfā€adaptation of tumor cells to ion concentration, however, puts forward higher requirements for the design of ionā€overloading strategy. Herein, ā€œblock and attackā€ antitumor strategy was applied through a composite nanomaterials (UHSsPZH NPs). The strategy demonstrated powerful ion interference ability through both ā€œblockingā€ the efflux of excess Zn2+ via gene silencing and ā€œattackingā€ tumor cells via target delivery of ZnO2. After cellular internalization, ZnO2 was degraded to Zn2+ and hydrogen peroxide (H2O2), and the gene expression of zinc transporter 1 (ZnT1) was silenced by targeting of released siRNA, which together caused intracellular Zn2+ā€overload. Disorder of Zn2+ further interfered with intracellular Ca2+ homeostasis, inhibited the electron transport chain and promoted the production of endogenous reactive oxygen species (ROS), which assisted the ā€œattackā€ to tumor cells together with the exogenous ROS generated by UHSsPZH NPs under 980Ā nm laser irradiation. In summary, this work supplies a ā€œblock and attackā€ strategy for the application of ion homeostasis interference in tumor therapy
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