On the electromagnetic form factors of hadrons in the time-like region near threshold

Abstract

Hadron electromagnetic form factor in the time-like region at the boundary of the physical region is considered. The energy behavior of the form factor is shown to be determined by the strong hadron-antihadron interaction. Imaginary parts of the scattering lengths for pp, ΛΛ, ΛΣ 0 (ΛΣ 0 ) and Σ 0Σ0 are estimated. Developed approach enables us to estimate imaginary part of the scattering volume from D * D * experimental data. The experiments to extract detailed information on the nearthreshold BB interaction from hadron form factor energy behavior are suggested.

The electromagnetic form factors of the proton in the timelike region

“…We could show that the near-threshold enhancement in the e + e − →pp cross section can be explained qualitatively bypp FSI effects in the 3 S 1 partial wave as generated by the Jülich nucleon-antinucleon model [21]. Similar results were also reported by other authors based on somewhat different approaches and employing otherNN interactions [29,30,31,32,33,34,35].…”

Study ofe+e−→pp¯via initial-state radiation atBABAR

“…The curve corresponds to the QCD-motivated fit described in the text. significant increase in the form factor as the pp threshold is approached may be due to final-state interactions between the proton and antiproton [28][29][30][31]. The rapid decreases of the form factor and cross section near 2.2 GeV/c 2 , 2.55 GeV/c 2 , and 3 GeV/c 2 have not been discussed in the literature.…”

Observation of a cross-section enhancement near mass threshold in e+e−→ΛΛAblikim1, Ачасов2, Ahmed3 et al. 2018Phys. Rev. D810580View full textAdd to dashboardCite

“…Recently, the BESIII experiment has observed a nonzero cross section near the Λ [17]. The unexpected features of baryon pair production near threshold have driven many theoretical interests [18] …”