2002/04/30 by The DELPHI Collaboration, J. Abdallah, P. Abreu +98 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1016/s0370-2693(02)01658-1
published as Phys.Lett.B533:243-252,2002 · 15 pages, 5 figures, Accepted by Phys. Lett. B
arxiv created 2002/04/30 · openalex publication_date 2002/05/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
Observation is made of rapidity-alignment of K+K- and ppbar pairs which results from their asymmetric orientation in rapidity, with respect to the direction from primary quark to antiquark. The K+K- and ppbar data are consistent with predictions from the fragmentation string model. However, the ppbar data strongly disagree with the conventional implementation of the cluster model. The non-perturbative process of `gluon splitting to diquarks' has to be incorporated into the cluster model for it to agree with the data. Local conservation of pT between particles nearby in rapidity (i.e., pT compensation) is analysed with respect to the thrust direction for pi+pi-, K+K-, and ppbar pairs. In this case, the string model provides fair agreement with the data. The cluster model is incompatible with the data for all three particle pairs. The model with its central premiss of isotropically-decaying clusters predicts a pT correlation not seen in the data.