Eur. Phys. J. A (2005) 25: 141-150
https://doi.org/10.1140/epja/i2005-10081-7

Original Article

Comparative Regge analysis of Λ,ΣΛ(1520) and Θ⁺ production in γp,πp and pp reactions

¹ Institute for Nuclear Research, 60th October Anniversary Prospect 7A, 117312, Moscow, Russia
² Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218, Moscow, Russia
³ Institute for Theoretical Physics, University of Giessen, Heinrich-Buff-Ring 16, D-35392, Giessen, Germany
⁴ INFN - Laboratori Nazionali di Frascati, Via E. Fermi, 40, CP 13, I-00044, Frascati (RM), Italy

^* e-mail: Wolfgang.Cassing@theo.physik.uni-giessen.de

Received: 22 March 2005
Accepted: 7 June 2005
Published online: 18 July 2005

Abstract

Using the Quark-Gluon Strings Model --combined with Regge phenomenology-- we perform a comparative analysis of Λ, Σ⁰, Λ(1520) and Θ⁺ production in binary reactions induced by photon, pion and proton beams on the nucleon. We find that the existing experimental data on the γp↦K ⁺Λ differential and total cross-sections can be described very well by the model for photon energies 1-16 GeV and - t < 2 GeV² assuming a dominant contribution of the K^* Regge trajectory. Moreover, using the same parameters we also reproduce the total γp↦K ⁺Σ⁰ and γp↦K ⁺Λ(1520) cross-sections suggesting a “universality” of the Regge model. In order to check the consistency of the approach we evaluate the differential and total cross-sections for the reaction π^- p↦K ⁰Λ which is also found to be dominated by the K^* Regge trajectory. Using the apparent “universality” of the Regge model we extend our scheme to the analysis of the binary reactions γp↦¯⁰Θ⁺, π^- p↦K ^-Θ⁺ and pp↦Σ⁺Θ⁺ as well as the exclusive and inclusive Θ⁺ production in the reactions pp↦p¯⁰Θ⁺ and pp↦Θ⁺ X. Our detailed studies demonstrate that Θ⁺ production does not follow the “universality” principle, thus suggesting an essentially different internal structure of the exotic baryon relative to conventional hyperons or hyperon resonances.