40,386 research outputs found

    Beam energy dependence of dd and dˉ\bar{d} productions in Au+Au collisions at RHIC

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    Light nuclei have much smaller binding energy compared to the temperature of the system created in heavy-ion collisions. Consequently, the distributions of light nuclei can be used to probe the freeze-out properties, such as correlation volume and local baryon density of the medium created in high-energy nuclear collisions. In this paper, we report the results of deuteron and anti-deuteron production in Au+Au collision at sNN\sqrt{s_\mathrm{NN}} = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by STAR at RHIC. The collision energy, centrality and transverse momentum dependence of the coalescence parameter B2B_2 for deuteron and anti-deuteron production are discussed. We find the values of B2B_2 for anti-deuteron are systematically lower than those for deuterons indicating the correlation volume of anti-baryon are larger than that of baryon. In addition, the values of B2B_2 are found to decrease with increasing collision energy and reach a minimum around sNN\sqrt{s_\mathrm{NN}} = 20 GeV implying a change of the equation of state of the medium in these collisions.Comment: 5 pages,6 figure

    Coulomb energy of axially deformed nucleus

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    We previously proposed a formula for calculating the Coulomb energy of spherical nucleus with Wood-Saxon charge distribution. In this work, the analytical formula is extended for description of the Coulomb energy of nucleus with beta2 deformation.Comment: 2 figure

    Dynamics of Gravity as Thermodynamics on the Spherical Holographic Screen

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    The dynamics of general Lovelock gravity, viewed on an arbitrary spherically symmetric surface as a holographic screen, is recast as the form of some generalized first law of thermodynamics on the screen. From this observation together with other two distinct aspects, where exactly the same temperature and entropy on the screen arise, it is argued that the thermodynamic interpretation of gravity is physically meaningful not only on the horizon, but also on a general spherically symmetric screen.Comment: 10 pages, revtex4; v2: minor corrections, references added? v3: the summary paragraph replaced by the discussion of the general static case, minor corrections/clarifications/modifications, references added, match the published versio
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