44 research outputs found

    Point Charge Dynamics Near a Grounded Conducting Plane

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    The classic image problem in electromagnetism involves a grounded infinite conducting plane and a point charge. The force of attraction between the point charge and the plane is identified using an equivalent-field picture of an image charge with opposite sign equidistant behind the plane resulting in a 1/{\it r}2^{\rm 2} force of attraction between the original charge and the plane. If the point charge is released from rest it will reach the plane in a time τ\tau. This time τ\tau has not been calculated correctly up to now. Clarification of the inconsistency is presented along with a correct solution to the classic image problem. Other electromagnetism problems are mentioned with attractive 1/{\it r}n^{\it n} forces (where {\it n} \ge 1). Such situations arise between a point charge and a line charge (1/{\it r}), between a line charge and a point dipole (1/{\it r}2^{2}), between a point charge and a point dipole (1/{\it r}3)^{3}), and between a point dipole and a second point dipole (1/{\it r}4^{4}).Comment: 6 pages, 4 figure

    Phi Meson Propagation and Decay at Finite Temperature

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    We study spectral properties of the phi meson at finite temperature using an effective Lagrangian together with finite-temperature field theory as a basis for modeling. General field-theoretic arguments are then used to establish the lifetime of the phi in hot hadronic matter. We find from the model, and we therefore propose a scenario in which, the phi decays inside the fireball. Early decays into μ+μ\mu^{+}\mu^{-} occur at high temperature while measurable hadronic decays into K+KK^{+}K^{-} (not suffering rescattering) occur at freezeout, where flow could be substantial. These results provide a consistent picture, if not possible interpretation of the NA49 and NA50 data from CERN.Comment: 7 pages, 3 postscript figures, Talk given at the 20th Winter Workshop on Nuclear Dynamics, Trelawny Beach, Jamaica, 15-20 March 200

    Short-Lived Phi Mesons

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    We use effective hadronic field theory to study in-medium properties of the ϕ\phi meson. The dominant decay channels \phi\toK^{+}K^{-} and ϕπρ\phi\to\pi\rho are modeled using an SU(3) chiral Lagrangian with normal and abnormal parities. The ϕ\phi self-energy is approximated to one-, two-, and even three-loop order in the strong coupling. Effects of modified spectral functions for π\pi, KK, ρ\rho and ϕ\phi are also included in the calculation. This allows us to study in-medium decay of phi mesons into (in-medium) kaon-pair daughters and (in-medium) πρ\pi\rho pairs. The results point to the possibility of rather short-lived ϕ\phi's, short enough to decay inside the fireball in relativistic heavy ion collisions. Implications relevant for the NA49 and NA50 experimental results, recently dubbed the ``ϕ\phi puzzle'', are discussed.Comment: 7 pages Latex, 4 figures, Talk presented at Hot Quarks 2004, July 18-24, 2004, Taos Valley, NM, US
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