Fermi and Gamow-Teller strength in charge exchange with radioactive beams

At forward angles, and bombarding energies E > 200 MeV, (p, n) and (n, p) reactions are thought to be directly proportional to the Gamow-Teller transition strengths in the nuclei. Assuming that this relationship also holds for charge exchange induced by high-energy heavy ions, this technique would be very useful in studies with radioactive beams. We show that the determination of Gamow-Teller and Fermi matrix elements from heavy-ion charge-exchange at forward angles is only useful for particular cases.