Oct 6 – 10, 2025
EIMI
Europe/Moscow timezone

Threshold amplification of X(a,b)Y reactions: from muon-catalyzed fusion to electromagnetic formfactors of hyperons

Oct 10, 2025, 12:20 PM
40m
Plenary talk Section B: Quantum field theory methods in elementary particle physics Plenary Session

Speaker

Vladimir Melezhik (BLTP JINR Dubna)

Description

Deviation of the cross section for the nuclear reaction X(a, b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed[1]. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behavior[2]. To analyze the effect, simple relations between the period and the amplitude of the oscillations with parameters of the interaction have been derived. Specifically, they predict the cross-section oscillations of fusion (or muon-catalyzed fusion) reactions of the type X(a,b)Y for slow collisions between nuclei (a) and atomic target (X), as, for example, the reaction D(d,p)T between deuterons (d) and deuterium atoms (D)[2]. Similar behavior we also observed in muon-catalyzed fusion collisional reactions pμ + p and tμ + d[2].
Recently, we have extended the formalism developed in [2] for descriptions of the cross section of Λ-hyperon production in e+ e- collisions at high energies
$e^+ + e^- \rightarrow Λ^+_c + Λ^-_c$ ,
obtained by the BESIII Collaboration [3]. The application of this formalism to the analysis of electromagnetic form factors is also discussed.

[1] L.N. Bogdanova et. al. Sov. J. Nucl. Phys. 34, 662 (1981); Phys. Lett. B115, 171 (1982).
[2] V.S. Melezhik, Nucl. Phys. A550, 223 (1992)
[3] M. Ablikim et. al.Phys. Rev. Lett. 131, 191901 (2023)

Author

Vladimir Melezhik (BLTP JINR Dubna)

Presentation materials