2016/08/30 by A.E. Asratyan, Asratyan, A. E., V. A. Matveev +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1608.08523
openalex publication_date 2016/08/30 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
The data on hadron--nucleus collisions at 400--700 GeV, collected by the SELEX experiment at Fermilab, are analyzed for formation of the exotic pentaquark baryon Θ+(1540). A narrow enhancement near 1539 MeV is observed in the mass spectrum of the pK0S system emitted at small xF from hadron collisions with copper nuclei. The statistical significance of the peak is near 9 standard deviations. Fitted width of the observed pK0S resonance is consistent with being entirely due to experimental resolution, and its intrinsic width is restricted to Γ< 3 MeV at 90% CL. The data favor positive rather than negative strangeness for the pK0S resonance observed in hCu collisions. At the same time, the pK0S mass spectrum for collisions in carbon is featureless. The yield of Θ+ baryons per hC collision is restricted to be < 24% of the yield per hCu collision.