Eur. Phys. J. A (2007) 31: 653-655
https://doi.org/10.1140/epja/i2006-10219-1

QNP 2006

Search for exotic baryons at HERMES

Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI, USA

^* e-mail: wdconinc@umich.edu

Received: 8 November 2006
Accepted: 15 November 2006
Published online: 1 March 2007

Abstract

An experimental search for the Θ(1540)- and Λ(1520)-resonance was performed in quasi-real photoproduction on deuterium at the HERMES experiment. While evidence for Θ(1540) was found in the decay channel pK ⁰ _S→pπ ⁺ π ^-, no evidence for the corresponding anti-particle was found. In some models it is expected that the Θ(1540) and the Λ(1520) have similar production mechanisms. The photoproduction cross-sections for the Λ(1520) in the decay channel Λ(1520)→pK ^- and the corresponding anti-particle are determined. The partial photoproduction cross-sections for Λ(1520) and ¯(1520) are obtained as σ _Λ(1520) = 65.3±8.8(stat)±6.9(syst)nb and σ _¯(1520) = 9.8±2.6(stat)±0.9(syst)nb, corresponding to a ratio R _Λ(1520) = σ _¯(1520)/σ _Λ(1520) = 0.15±0.05(stat)±0.02(syst).