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String Breaking as a Mixing Phenomenon in the SU(2) Higgs Model

F. Knechtli·R. Sommer
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Abstract

We study the potential of a static quark anti-quark pair in the confinement ``phase'' of the SU(2) Higgs model. Around separation r_b, the confining string of the gauge field breaks by formation of a dynamical pair of light quarks. The ground state and first excited state static potentials are determined by a variational technique from a matrix correlation in which suitably smeared gauge and Higgs fields enter. Our results at beta=2.4 clearly show string breaking (r_b ~ 1.9r_0). The investigation of properly defined overlaps confirms the interpretation of string breaking as a level crossing phenomenon between string-type and meson-type states. We study the scaling properties of the static potentials along a line of constant physics, varying the lattice spacing by a factor of 2. Our results show compatibility with scaling within tiny errors.

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F. Knechtli, R. Sommer. 2000-05-26. String Breaking as a Mixing Phenomenon in the SU(2) Higgs Model. https://doi.org/10.1016/s0550-3213(00)00470-3

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