Uncertainty quantification for proton-proton fusion in chiral effective field theory
Journal article, 2016

We compute the S-factor of the proton-proton (pp) fusion reaction using chiral effective field theory (chi EFT) up to next-to-next-to-leading order (NNLO) and perform a rigorous uncertainty analysis of the results. We quantify the uncertainties due to (i) the computational method used to compute the pp cross section in momentum space, (ii) the statistical uncertainties in the low-energy coupling constants of chi EFT, (iii) the systematic uncertainty due to the chi EFT cutoff, and (iv) systematic variations in the database used to calibrate the nucleon-nucleon interaction. We also examine the robustness of the polynomial extrapolation procedure, which is commonly used to extract the threshold S-factor and its energy-derivatives. By performing a statistical analysis of the polynomial fit of the energy-dependent S-factor at several different energy intervals, we eliminate a systematic uncertainty that can arise from the choice of the fit interval in our calculations. In addition, we explore the statistical correlations between the S-factor and few-nucleon observables such as the binding energies and point-proton radii of H-2,H-3 and He-3 as well as the D-state probability and quadrupole moment of H-2, and the beta-decay of 3H. We find that, with the state-of-the-art optimization of the nuclear Hamiltonian, the statistical uncertainty in the threshold S-factor cannot be reduced beyond 0.7%.


B. Acharya

University of Tennessee

Boris Karlsson

Chalmers, Physics, Subatomic and Plasma Physics

Andreas Ekström

Chalmers, Physics, Subatomic and Plasma Physics

Christian Forssen

Chalmers, Physics, Subatomic and Plasma Physics

L. Platter

Oak Ridge National Laboratory

University of Tennessee

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

0370-2693 (ISSN)

Vol. 760 584-589

Ab initio approach to nuclear structure and reactions (++) (ANSR)

European Commission (EC) (EC/FP7/240603), 2009-12-01 -- 2014-11-30.

Subject Categories

Subatomic Physics

Physical Sciences

Astronomy, Astrophysics and Cosmology

Earth and Related Environmental Sciences


Basic sciences


C3SE (Chalmers Centre for Computational Science and Engineering)



More information

Latest update

3/2/2022 3