Speaker
Dr
Stefan Typel
(IKP, Technische Universität Darmstadt)
Description
Breakup reactions were proposed in 1986 by Gerhard Baur as an indirect method to investigate
low-energy charged-particle reactions relevant for nuclear astrophysics [1].
This so-called 'Trojan-Horse method' (THM) allows to extract cross sections of two-particle
reactions from suitable transfer reactions with three particles in the final state using
quasifree scattering conditions. A specific feature of the approach is the suppression
of the Coulomb barrier effect that causes a strong reduction of the cross section
of astrophysical reactions at low energies.
The THM is applicable to general rearrangement reactions
in contrast to other indirect techniques such as the Coulomb dissociation (CD) method or asymptotic
normalization coefficient (ANC) method, which aim at radiative capture reactions.
The analysis of dedicated laboratory experiments using the THM
requires the application of nuclear reaction theory. In this contribution, the development of
the theoretical description is presented starting from the early ideas with simple
approximations, e.g., a modified plane-wave impulse approximation (PWIA) that allowed to factorize the THM cross section as a product of a kinematic factor, a momentum distribution and a half-off-shell two-body cross section. Different applications are considered, in particular, elastic scattering,
non-resonant and resonant reactions. Suggestions for possible improvements
in the future development of the theory are given.
[1] G. Baur, Phys. Lett. B 178, 135 (1986).
Primary author
Dr
Stefan Typel
(IKP, Technische Universität Darmstadt)
