Eur. Phys. J. A (2006) 29: 221-225
https://doi.org/10.1140/epja/i2006-10073-1

Hadron Physics

Search for the Θ1540) in lattice QCD

Institut für theoretische Physik, Universität Regensburg, D-93040, Regensburg, Germany

^* e-mail: dieter.hierl@physik.uni-regensburg.de

Received: 18 January 2006
Accepted: 24 July 2006
Published online: 29 August 2006

Abstract

We report on a study of the pentaquark Θ⁺(1540), using a variety of different interpolating fields. We use chirally improved fermions in combination with Jacobi-smeared quark sources to improve the signal and get reliable results even for small quark masses. The results of our quenched calculations, which have been done on a 12³×24 lattice with a lattice spacing of a = 0.148fm, do not provide any evidence for the existence of a Θ⁺ with positive parity. We do observe, however, a signal compatible with nucleon-kaon scattering state. For the negative parity the results are inconclusive, due to the potential mixture with nucleon-kaon and N^*-kaon scattering states.