String breaking by light and strange quarks in QCD

The energy spectrum of a system containing a static quark anti-quark pair is computed for a wide range of source separations using lattice QCD with Nf=2+1 dynamical flavours. By employing a variational method with a basis including operators resembling both the gluon string and systems of two separa...

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Bibliographic Details
Main Authors: John Bulava, Ben Hörz, Francesco Knechtli, Vanessa Koch, Graham Moir, Colin Morningstar, Mike Peardon
Format: Article
Language:English
Published: Elsevier 2019-06-01
Series:Physics Letters B
Online Access:http://www.sciencedirect.com/science/article/pii/S0370269319303284
Description
Summary:The energy spectrum of a system containing a static quark anti-quark pair is computed for a wide range of source separations using lattice QCD with Nf=2+1 dynamical flavours. By employing a variational method with a basis including operators resembling both the gluon string and systems of two separated static mesons, the first three energy levels are determined up to and beyond the distance where it is energetically favourable for the vacuum to screen the static sources through light- or strange-quark pair creation, enabling both these screening phenomena to be observed. The separation dependence of the energy spectrum is reliably parameterised over this saturation region with a simple model which can be used as input for subsequent investigations of quarkonia above threshold and heavy-light and heavy-strange coupled-channel meson scattering. Keywords: Lattice QCD, String breaking, Heavy quarks
ISSN:0370-2693