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Proton-proton weak capture in chiral effective field theory
L E Marcucci1, R Schiavilla, M Viviani
1Department of Physics, University of Pisa, 56127 Pisa, Italy and INFN-Pisa, 56127 Pisa, Italy.
Physical Review Letters
|May 28, 2013
Summary
This study calculates the astrophysical S factor for proton-proton weak capture using chiral effective field theory. The findings provide precise values crucial for understanding nuclear reactions and astrophysics.
Area of Science:
- Nuclear Physics
- Astrophysics
- Quantum Field Theory
Background:
- Proton-proton weak capture is a fundamental process in astrophysics.
- Accurate calculation of the astrophysical S factor is essential for stellar evolution models.
- Chiral effective field theory provides a systematic framework for nuclear forces.
Purpose of the Study:
- To calculate the astrophysical S factor for proton-proton weak capture with high precision.
- To incorporate electromagnetic interactions and higher-order corrections.
- To constrain low-energy constants using experimental data from light nuclei.
Main Methods:
- Chiral effective field theory up to next-to-next-to-next-to leading order.
- Inclusion of full electromagnetic interaction, including two-photon and vacuum-polarization corrections.
- Fitting of low-energy constants to A=3 binding energies, magnetic moments, and tritium beta decay.
Main Results:
- The S factor at zero energy was determined to be S(0)=(4.030±0.006)×10⁻²³ MeV fm².
- A P-wave contribution of 0.020×10⁻²³ MeV fm² was identified.
- Theoretical uncertainty arises from fitting procedures and cutoff dependence.
Conclusions:
- The calculated S factor provides a precise theoretical prediction for proton-proton weak capture.
- This result can refine astrophysical models and tests of fundamental physics.
- The methodology offers a pathway for future calculations of similar nuclear processes.
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