424,223 research outputs found

    Chiral expansion of the π0γγ\pi^0\rightarrow\gamma\gamma decay width

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    A chiral field theory of mesons has been applied to study the contribution of the current quark masses to the π0γγ\pi^0\rightarrow\gamma\gamma decay width at the next leading order. 2%2\% enhancement has been predicted and there is no new parameter.Comment: 9 page

    A flexible error estimate for the application of centre manifold theory

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    In applications of centre manifold theory we need more flexible error estimates than that provided by, for example, the Approximation Theorem 3 by Carr [4, 6]. Here we extend the theory to cover the case where the order of approximation in parameters and that in dynamical variables may be completely different. This allows, for example, the effective evaluation of low-dimensional dynamical models at finite parameter values

    Excitation function of nucleon and pion elliptic flow in relativistic heavy-ion collisions

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    Within a relativistic transport (ART) model for heavy-ion collisions, we show that the recently observed characteristic change from out-of-plane to in-plane elliptic flow of protons in mid-central Au+Au collisions as the incident energy increases is consistent with the calculated results using a stiff nuclear equation of state (K=380 MeV). We have also studied the elliptic flow of pions and the transverse momentum dependence of both the nucleon and pion elliptic flow in order to gain further insight about the collision dynamics.Comment: 8 pages, 2 figure

    Isotopic Equivalence from Bezier Curve Subdivision

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    We prove that the control polygon of a Bezier curve B becomes homeomorphic and ambient isotopic to B via subdivision, and we provide closed-form formulas to compute the number of iterations to ensure these topological characteristics. We first show that the exterior angles of control polygons converge exponentially to zero under subdivision.Comment: arXiv admin note: substantial text overlap with arXiv:1211.035