STAR Collaboration2023-07-212023-07-212023STAR Collaboration. "Beam Energy Dependence of Triton Production and Yield Ratio (Nt×Np/N2d) in Au+Au Collisions at RHIC." <i>Physical Review Letters,</i> 130, no. 20 (2023) American Physical Society: https://doi.org/10.1103/PhysRevLett.130.202301.https://hdl.handle.net/1911/114978We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at √sNN=7.7–200 GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (Nt×Np/N2d), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dNch/dη) and follows a scaling behavior. The dNch/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller pT acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.engThis work is protected by copyright, and is made available here for research and educational purposes. Permission to reuse, publish, or reproduce the work beyond the bounds of Fair Use or other exemptions to copyright law must be obtained from the copyright holder.Journal articlePhysRevLett-130-202301https://doi.org/10.1103/PhysRevLett.130.202301