Abstract
Despite the number of inclusive measurements of the pionic fusion reactions, the nature of the ABC effect discovered in 1960 was not completely established. Exclusive measurements of the doublepion-production reactions leading to either fused d, 3He and 4He nuclear final states or pp pairs are analyzed. A significant ABC effect—enhancement in the region of low ππ mass—is found only in the isoscalar ππ channel while in the isovector channels it is small or absent. For the reaction with isovector pp final state an ABC effect was not observed even at the special kinematic conditions to reproduce a quasi-bound two-proton state. The total cross sections for the d and 4He fusion reactions show similar resonance-like energy dependence.
Similar content being viewed by others
References
N. E. Booth, A. Abashian, and K. M. Crowe, Phys. Rev. Lett. 7, 35 (1961); 5, 258 (1960); A. Abashian, N. E. Booth, K. M. Crowe, et al., Phys. Rev. C 132, 2296 (1963).
J. D. Dowell, R. J. Homer, Q. H. Khan, et al., Phys. Lett. 12, 252 (1964).
J. H. Hall et al., Nucl. Phys. B 12, 573 (1969).
I. Bar-Nir et al., Nucl. Phys. B 54, 17 (1973).
J. Banaigs et al., Nucl. Phys. B 67, 1 (1973).
J. Banaigs et al., Nucl. Phys. B 105, 52 (1976).
Chr. Bargholtz et al., Phys. Lett. B 398, 264 (1997).
K. R. Chapman et al., Phys. Lett. 21, 465 (1966).
F. Plouin et al., Nucl. Phys. A 302, 413 (1978).
M. Bashkanov et al., Phys. Rev. Lett. 102, 052301 (2009); O. Khakimova et al., Int. J. Mod. Phys. A 22, 617 (2007).
M. Bashkanov et al., Phys. Lett. B 637, 223 (2006).
A. Pricking, PhD Thesis (Univ. Tuebingen, 2011); P. Adlarson et al., Phys. Rev. C 86, 032201(R) (2012).
P. Adlarson et al., Phys. Rev. Lett. 106, 242302 (2011).
S. Keleta et al., Nucl. Phys. A 825, 71 (2009).
F. Kren et al., Phys. Lett. B 684, 110 (2010).
T. Risser and M. D. Shuster, Phys. Lett. B 43, 68 (1973).
T. Skorodko et al., Phys. Lett. B 695, 115 (2011).
L. Alvarez-Ruso, E. Oset, and E. Hernández, Nucl. Phys. A 633, 519 (1998); L. Alvarez-Ruso, Phys. Lett. B 452, 207 (1999); PhD Thesis (Univ. Valencia, 1999).
Author information
Authors and Affiliations
Corresponding author
Additional information
The text was submitted by the authors in English.
Rights and permissions
About this article
Cite this article
Doroshkevich, E.A., Bashkanov, M.A., Clement, H. et al. Observation of the ABC effect and final-state isospin. Phys. Atom. Nuclei 77, 936–940 (2014). https://doi.org/10.1134/S1063778814070047
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063778814070047