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The pentaquark $Θ^+(1540)$ in the string model

M. I. Krivoruchenko·B. V. Martemyanov·Amand Faessler·C. Fuchs
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Abstract

We consider the $Θ^+(1540)$ pentaquark in the string model that correctly reproduces the linear Regge trajectories for the case of orbital excitations of light $q\bar q$ mesons and $qqq$ baryons. Assuming (and arguing in favour of) the diquark-antiquark-diquark ($[ud]\bar s [ud]$) clustering of this orbitally excited object we found its mass about $290 \rm {MeV}$ above the experimental value $1540 \rm {MeV}$. In the model considered this discrepancy could be attributed to the change of the constituent mass of $\bar s$ antiquark as compared to that of $s$ quark localized at the string end.

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M. I. Krivoruchenko, B. V. Martemyanov, Amand Faessler, C. Fuchs. 2005-02-02. The pentaquark $Θ^+(1540)$ in the string model. https://doi.org/10.1103/physrevd.71.017502

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