The light nuclei yields and yield ratios, as sensitive probes of the QCD phase transition, have been precisely measured at various collision energies.However, due to limited detector acceptance, the full $p_{ \rm T}$ integral yield often requires extrapolation of the measured transverse momentum spectra to the unmeasured low-$p_{ \rm T}$ region via functional fitting.Simulations with the AMPT-HC transport model and an after-burner coalescence approach indicate a significant low-$p_{ \rm T}$ enhancement in peripheral collisions or forward rapidities, primarily originating from spectator nucleons.Consequently, conventional extrapolations tend to underestimate the true light nuclei yields.
Categories: hep-ph