High-Precision Measurement of D ( γ , n ) p Photodisintegration Reaction and Implications for Big Bang Nucleosynthesis
Year: 2026
Type: article
Abstract: We report on a high-precision measurement of the D(γ,n)p photodisintegration reaction at the newly commissioned Shanghai Laser Electron Gamma Source, employing a quasimonochromatic γ-ray beam from Laser Compton Scattering. The cross sections were determined over E_{γ}=2.327-7.089 MeV, achieving up to a factor of 2.2 improvement in precision near the neutron separation threshold. Combined with previous data in a global Markov chain Monte Carlo analysis using dibaryon effective field theory, we obtained the unprecedentedly precise p(n,γ)D cross sections and thermonuclear rate, with a precision up to ≈4 times higher than previous evaluations. Implemented in a standard Big Bang nucleosynthesis framework, this new rate decreases uncertainty of the key cosmological parameter of baryon density Ω_{b}h^{2} by up to ≈16% relative to the Laboratory for Underground Nuclear Astrophysics (LUNA) result. A residual ≈1.2σ tension between Ω_{b}h^{2} constrained from primordial D/H observations and cosmic microwave background measurements persists, highlighting the need for improved dd reaction rates and offering potential hints of new physics beyond the standard model of cosmology.
Source: Physical Review Letters
DOI: 10.1103/tbbt-s819
Authors: Y. J. Chen, Z. R. Hao, J. J. He, T. Kajino, S.-I. Ando, Y. Luo, H. R. Feng, L. Y. Zhang, G. T. Fan, H. W. Wang, H. Zhang, Z. L. Shen, L. X. Liu, H. H. Xu, Y. Zhang, P. Jiao, X. Y. Li, Y. X. Yang, S. Jin, K. J. Chen, W. Q. Shen, Y. G. Ma
Institutions: Fudan University, Shanghai Advanced Research Institute, National Astronomical Observatory of Japan, The University of Tokyo, Beihang University, Sun Moon University, Daegu University, Peking University, Beijing Normal University, Shanghai Institute of Applied Physics, National Natural Science Foundation of China, East China Normal University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4415088906