Breakup and Incomplete Fusion Reactions in <sup>7</sup>Be + <sup>208</sup>Pb
ORAL
Abstract
Light, weakly-bound nuclei reacting with heavy targets at energies above the fusion barrier are observed to have significant suppression of complete fusion when compared with single-barrier penetration models [1][2]. This suppression is accompanied by incomplete fusion yields, where only partial charge capture occurs. Prior measurements of breakup yields and characteristic timescales show that this cannot be explained by projectile breakup or transfer-triggered breakup reactions alone [3][4][5].
Instead, direct cluster transfer has been proposed as an alternative mechanism, consistent with measured α yields resulting from incomplete fusion [3]. These reaction dynamics are influenced by the projectile’s clustering structure and weak-binding, which plays a more significant role away from stability [6][7][8]. Therefore, to continue probing this interplay, we measured the breakup and fusion of 7Be on 208Pb at above barrier energies. By comparing the breakup of 7Be and its mirror nucleus, 7Li, we can decouple the effects of structure and weak-binding in complete fusion suppression. The ongoing analysis of the 7Be breakup data will be discussed.
[1] Dasgupta et al., Phys. Rev. C 70 (2004)
[2] Signorini et al., Eur. Phys. A 5, 7 (1999)
[3] Cook et al., Phys. Rev. C 122, 102501 (2019)
[4] Luong et al., Phys. Lett. B 695, 105 (2011)
[5] Shrivastava et al., Phys. Lett. B 633, 463 (2006)
[6] Cook et al., Phys. Rev. C 93 (2016)
[7] Simpson et al., Phys. Rev. C 93, 24605 (2016)
[8] Kalkal et al., Phys. Rev. C 93, 044605 (2016)
Instead, direct cluster transfer has been proposed as an alternative mechanism, consistent with measured α yields resulting from incomplete fusion [3]. These reaction dynamics are influenced by the projectile’s clustering structure and weak-binding, which plays a more significant role away from stability [6][7][8]. Therefore, to continue probing this interplay, we measured the breakup and fusion of 7Be on 208Pb at above barrier energies. By comparing the breakup of 7Be and its mirror nucleus, 7Li, we can decouple the effects of structure and weak-binding in complete fusion suppression. The ongoing analysis of the 7Be breakup data will be discussed.
[1] Dasgupta et al., Phys. Rev. C 70 (2004)
[2] Signorini et al., Eur. Phys. A 5, 7 (1999)
[3] Cook et al., Phys. Rev. C 122, 102501 (2019)
[4] Luong et al., Phys. Lett. B 695, 105 (2011)
[5] Shrivastava et al., Phys. Lett. B 633, 463 (2006)
[6] Cook et al., Phys. Rev. C 93 (2016)
[7] Simpson et al., Phys. Rev. C 93, 24605 (2016)
[8] Kalkal et al., Phys. Rev. C 93, 044605 (2016)
*This work was supported by the US Department of Energy office under DE-SC0021938 and DE-SC0022299 as well as the Office of Science, Office of Nuclear Physics and used resources of the Facility for Rare Isotope Beams (FRIB), which is a DOE Office of Science User Facility, operated by Michigan State University, under Award Number DE-SC0023633
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Publication: I.M. Harca, M.J. Basson , K.J. Cook, K.W. Brown, S.A. Gillespie, A.K. Anthony, N.E. Esker, S.N. Paneru —The FABLE silicon detector array for comprehensive studies of fusion and breakup dynamics, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1077, 170527 (2025).
Presenters
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Marshall J Basson
- Michigan State University