Study of Neutron Emission from Target Spectators in $${}^{{124}}$$Xe $${+}$$ CsI Collisions at 3.8 A GeV

The measurement of neutron energy spectra in $${}^{124}$$ Xe $$+$$ CsI collisions at 3.8 A GeV was made with a compact TOF neutron spectrometer of the BM@N experiment in energy interval up to 200 MeV for emission angles of 95 $${{}^{\circ}}$$ , 110 $${{}^{\circ}}$$ , and 121 $${{}^{\circ}}$$ . Main source of these neutrons is decay of excited target spectators. In the energy region below 20 MeV the angular distribution of neutrons is isotropic and it indicates that the velocity of this neutron source is close to zero. It corresponds to low momentum transfer from projectile nuclei to spectators. The comparison of the experimental results with prediction of theoretical model DCM-QGSM-SMM shows a large underestimation of the neutron yield below 8 MeV by the model.