Enhanced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-Factor for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mmultiscripts><mrow><mi mathvariant="normal">N</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>14</mn></mrow></mmultiscripts></mrow><mo stretchy="false">(</mo><mi>p</mi><mo>,</mo><mi>γ</mi><msup><mrow><mo stretchy="false">)</mo></mrow><mrow><mn>15</mn></mrow></msup><mi mathvariant="normal">O</mi></mrow></math> Reaction and Its Impact on the Solar Composition Problem

X. Chen; J. Su; Y. P. Shen; L. Y. Zhang; J. J. He; S. Z. Chen; S. Wang; Z. L. Shen; S. Lin; L. Y. Song; H. Zhang; L. H. Wang; X. Z. Jiang; L. Wang; Y. T. Huang; Z. W. Qin; F. C. Liu; Y. D. Sheng; Y. J. Chen; Y. L. Lu; X. Y. Li; J. Y. Dong; Y. C. Jiang; Y. Q. Zhang; Y. Zhang; J. W. Tian; D. Xiao; Y. Zhang; Z. M. Li; X. C. Han; J. J. Wei; H. Li; Z. An; W. P. Lin; B. Liao; H. N. Liu; F. S. Zhang; M. L. Qiu; C. Xu; S. L. Jin; F. Lu; J. F. Chen; W. Nan; Y. B. Wang; Z. H. Li; B. Guo; Y. Q. Gu; W. P. Liu

doi:10.1103/q756-hzmt

Enhanced $S$ -Factor for the ${}^{14}N (p, γ)^{15} O$ Reaction and Its Impact on the Solar Composition Problem

X. Chen ¹, J. Su ^1,*, Y. P. Shen ^2,†, L. Y. Zhang¹, J. J. He^3,1, S. Z. Chen ⁴, S. Wang ⁵, Z. L. Shen¹, S. Lin ¹ et al.

L. Y. Song¹, H. Zhang^3,1, L. H. Wang ⁶, X. Z. Jiang¹, L. Wang¹, Y. T. Huang¹, Z. W. Qin¹, F. C. Liu ¹, Y. D. Sheng¹, Y. J. Chen^3,1, Y. L. Lu¹, X. Y. Li ³, J. Y. Dong ², Y. C. Jiang ², Y. Q. Zhang², Y. Zhang², J. W. Tian ², D. Xiao ⁴, Y. Zhang⁴, Z. M. Li ⁷, X. C. Han⁵, J. J. Wei ⁸, H. Li ⁸, Z. An ⁹, W. P. Lin ⁹, B. Liao¹, H. N. Liu¹, F. S. Zhang ¹, M. L. Qiu¹, C. Xu ¹, S. L. Jin¹⁰, F. Lu ¹¹, J. F. Chen ¹², W. Nan ², Y. B. Wang ², Z. H. Li ², B. Guo², Y. Q. Gu ¹³, and W. P. Liu^14,2,‡

¹Key Laboratory of Beam Technology of Ministry of Education, School of Physics and Astronomy, Beijing Normal University, Beijing 100875, China
²China Institute of Atomic Energy, P. O. Box 275(10), Beijing 102413, China
³Key Laboratory of Nuclear Physics and Ion-beam Application (MoE), Institute of Modern Physics, Fudan University, Shanghai, 200433, China
⁴Institute of Nuclear Energy Safety Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
⁵Shandong Provincial Key Laboratory of Nuclear Science, Nuclear Energy Technology and Comprehensive Utilization, Weihai Frontier Innovation Institute of Nuclear Technology, School of Nuclear Science, Energy and Power Engineering, Shandong University, Shandong 250061, China
⁶School of Mathematics and Physics, Handan University, Handan 056005, China
⁷Harbin Engineering University, Harbin, Heilongjiang, 150000, China
⁸Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
⁹Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China
¹⁰Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
¹¹Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
¹²State Key Laboratory of Functional Crystals and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
¹³Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China
¹⁴Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China

^*Contact author: sujun@bnu.edu.cn
^†Contact author: ypshen@ciae.ac.cn
^‡Contact author: liuwp@sustech.edu.cn

PDF

Phys. Rev. Lett. 135, 232701 – Published 2 December, 2025

DOI: https://doi.org/10.1103/q756-hzmt

Abstract

The solar composition problem has puzzled astrophysicists for more than 20 years. Recent measurements of carbon-nitrogen-oxygen (CNO) neutrinos by the Borexino experiment show a $\sim 2 σ$ tension with the “low-metallicity” determinations. ${}^{14}N (p, γ)^{15} O$ , the slowest reaction in the CNO cycle, plays a crucial role in the standard solar model (SSM) calculations of CNO neutrino fluxes. Here we report a direct measurement of the ${}^{14}N (p, γ)^{15} O$ reaction, in which $S$ -factors for all transitions were simultaneously determined in the energy range of $E_{p} = 110 - 260 keV$ for the first time. Our results resolve previous discrepancies in the ground-state transition, yielding a zero-energy $S$ -factor $S_{114} (0) = 1.93 \pm 0.10 keV b$ , which is 15% higher than the $1.68 \pm 0.14 keV b$ recommended in Solar Fusion III (SF-III). With our $S_{114}$ values, the SSM B23-MB22p, and the latest global analysis of solar neutrino measurements, the C and N photospheric abundance determined by the Borexino experiment is updated to $N_{CN} = (4.4 2_{- 0.63}^{+ 0.70}) \times 10^{- 4}$ . This new $N_{CN}$ value agrees well with latest “high-metallicity” composition; however, it is also consistent with the “low-metallicity” determination within $\sim 1 σ$ CL, indicating that the solar metallicity problem remains an open question. In addition, the significant reduction in the uncertainty of $S_{114}$ paves the way for the precise determination of the CN abundance in future large-volume solar neutrino measurements.

Physical Review Letters

Export citation

Export citation

Enhanced $S$ -Factor for the ${}^{14}N (p, γ)^{15} O$ Reaction and Its Impact on the Solar Composition Problem

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Other Options

Supplemental Material (Subscription Required)

References (Subscription Required)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation

Enhanced S-Factor for the N14(p,γ)15O Reaction and Its Impact on the Solar Composition Problem

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Log in via your institution

Log in via APS Member Subscription

Other Options

Supplemental Material (Subscription Required)

References (Subscription Required)

Enhanced $S$ -Factor for the ${}^{14}N (p, γ)^{15} O$ Reaction and Its Impact on the Solar Composition Problem