2008/12/17 by R. Baldini, S. Pacetti, Baldini, R. +3
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Superconducting Materials and Applications #hep-ph
paper · pdf · doi:10.48550/arxiv.0812.3283
10 pages, 9 figures
openalex publication_date 2008/12/17 · arxiv created 2009/01/19 · arxiv updated 2009/12/01 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
A peculiar feature, observed in the BaBar data on e+e- -> baryon-antibaryon cross sections, is the non-vanishing cross section at threshold for all these processes. This is the expectation due to the Coulomb enhancement factor acting on a charged fermion pair. Remarkably, in the case of e+e- -> p-pbar it is found that Coulomb final state interactions largely dominate the cross section at threshold and it turns out a form factor |G(4Mp2)|~1, as a point-like fermion. Also in the case of e+e- -> Lambdac-antiLambdac, as recently measured by Belle for the first time, a point-like behavior is suggested for the charmed charged baryon, being the Lambdac form factor at threshold |G|~1, even if within a large error. In the case of neutral strange baryons the non-vanishing cross section at threshold is interpreted as a remnant of quark pair Coulomb interaction before the hadronization, taking into account the asymmetry between attractive and repulsive Coulomb factors. Besides strange baryon cross sections are successfully compared to U-spin invariance relationships.