M. Kobayashi,*¹ K. Yako,*¹ S. Shimoura,*¹ M. Dozono,*² S. Kawase,*¹ K. Kisamori,*¹,*² Y. Kubota,*¹,*² C.S. Lee,*¹,*² S. Michimasa,*¹ H. Miya,*¹,*² S. Ota,*¹ H. Sakai,*² M. Sasano,*² and M. Takaki*¹ Charge-exchange ( p, n ) reactions at intermediate en- ergies ( E > 100 MeV) serve as powerful tools to study spin-isospin responses of nuclei; Gamow-Teller (GT) transitions are a particular example of such reactions. In the present work, we focused on the neutron-rich nu- cleus 8He, which has the largest neutron-to-proton ra- tio among all known particle-stable nuclei ( N/Z = 3). It can be described as an α -particle surrounded by four valence neutrons, exhibiting a neutron halo or thick neutron skin. We measured the 8He(p,n)8Li reaction at 190A MeV in inverse kinematics in order to study the spin-isospin response of 8He. This is the first mea- surement of the charge-exchange reaction on 8He. The experiment was performed at the RIKEN RI Beam Factory (RIBF). Recoil neutrons with low ki- netic energies from the ( p,n ) reactions were detected by the recently developed neutron detector WINDS. 1) The residual nucleus 8Li and its decay product 7Li were detected using auxiliary beam line detectors, a plas- tic scintillator, and a multi-wire drift chamber (LP- MWDC)²), installed at FH10, which is downstream from the secondary target at FH9.  A superconducting triplet quadrupole (STQ) was installed between FH9 and FH10.  The triton decay channel of the excited state in 8Li was not tagged in this measurement. Double differential cross sections for the 8He(p,n)8Li reaction at excitation energies of 0–20 MeV and neu- tron energies of 2.0–4.4 MeV, which correspond to mo- mentum transfers of 0.31–0.46 fm–1, were obtained. Figure 1 shows the double differential cross sections for T n = 2.0–2.6 MeV, corresponding to q = 0.31– 0.35 fm-1. In the spectrum, two peaks were observed at ～ 1 MeV and ～ 8 MeV. The lower peak corresponds to the first excited 1+ state of 8Li at 0.98 MeV. The angular distributions of the cross sections for the peaks at ～ 1 MeV and ～ 8 MeV are shown in Fig. 2. In this figure, the differential cross sections were corrected for the transmission efficiencies between FH9 and FH10. They were compared to the results of distorted wave impulse approximation (DWIA) calcu- lations. The angular distribution of the peak at ～ 1 MeV, which is a flat distribution, was reproduced well by the sum of the 0.98-MeV state ( J π = 1 + ) and the ground state ( J π = 2 + ). The cross sections at q = 0 for the 0.98-MeV and 8-MeV states were ex- tracted. We then calculated the GT strength B (GT) for the 8-MeV state by using the extracted cross sec- tions at q = 0 and the known B (GT) value of 0.24 for the 0.98-MeV state.  The obtained GT strength was B(GT) ～ 8 for the neutron decay channel of the 8-MeV state. It is known that the excited state at ～ 9 MeV with a large GT strength of B (GT) ～ 5 decays primarily by triton emission. 3,4) In contrast, we observed, for the first time, a neutron decay channel of the resonance state with a large B (GT) strength.  This result sug- gests that most of the GT strength is concentrated in the resonance state at ～ 8 MeV. The observed state is most likely the Gamow-Teller resonance of 8 He. Fur- ther analysis is in progress.