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Theta+ formation in inclusive gamma D -> pK- X

A. I. Titov·B. Kämpfer·S. Daté·Y. Ohashi
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Abstract

We analyze the possibility to produce an intermediate Theta^+ via a KN->Θ+ formation process in gamma D-> pK^- X (X=nK^+,pK^0) reactions at some specific kinematical conditions, in which a pK^- pair is knocked out in the forward direction and its invariant mass is close to the mass of Lambda(1520). The Θ^+ signal may appear in the [γD,pK^-] missing mass distribution. The ratio of the signal (cross section at the Θ^+ peak position) to the smooth background processes varies from 0.7 to 2.5 depending on the spin and parity of Theta+, and it decreases correspondingly if the pK^- invariant mass is outside of the Lambda(1520)-resonance region. We analyze the recent CLAS search for the Theta+ in the gamma D ->pK^-nK^+ reaction and show that the conditions of this experiment greatly reduce the Theta+ formation process making it difficult to extract a Theta+ peak from the data.

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A. I. Titov, B. Kämpfer, S. Daté, Y. Ohashi. 2006-07-26. Theta+ formation in inclusive gamma D -> pK- X. https://doi.org/10.1103/physrevc.74.055206

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