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arXiv · 1212.1418

Lattice investigation of the scalar mesons a_0(980) and κ using four-quark operators

Constantia Alexandrou·Jan Oliver Daldrop·Mattia Dalla Brida·Mario Gravina·Luigi Scorzato·Carsten Urbach·Marc Wagner
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Abstract

We carry out an exploratory study of the isospin one a0(980) and the isospin one-half kappa scalar mesons using Nf=2+1+1 Wilson twisted mass fermions at one lattice spacing. The valence strange quark is included as an Osterwalder-Seiler fermion with mass tuned so that the kaon mass matches the corresponding mass in the unitary Nf=2+1+1 theory. We investigate the internal structure of these mesons by using a basis of four-quark interpolating fields. We construct diquark-diquark and molecular-typecinterpolating fields and analyse the resulting correlation matrices keeping only connected contributions. For both channels, the low-lying spectrum is found to be consistent with two-particle scattering states. Therefore, our analysis shows no evidence for an additional state that can be interpreted as either a tetraquark or a tightly-bound molecular state.

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Constantia Alexandrou, Jan Oliver Daldrop, Mattia Dalla Brida, Mario Gravina, Luigi Scorzato, Carsten Urbach, Marc Wagner. 2012-12-06. Lattice investigation of the scalar mesons a_0(980) and κ using four-quark operators. https://doi.org/10.1007/jhep04(2013)137

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