# Parameter-free effective field theory calculation for the solar proton-fusion and hep processes

## Abstract

Spurred by the recent complete determination of the weak currents in two-nucleon systems up to {Omicron}(Q{sup 3}) in heavy-baryon chiral perturbation theory, we carry out a parameter-free calculation of the threshold S-factors for the solar pp (proton-fusion) and hep processes in an effective field theory that combines the merits of the standard nuclear physics method and systematic chiral expansion. The power of the EFT adopted here is that one can correlate in a unified formalism the weak-current matrix elements of two-, three- and four-nucleon systems. Using the tritium {beta}-decay rate as an input to fix the only unknown parameter in the theory, we can evaluate the threshold S factors with drastically improved precision; the results are S{sub pp}(0) = 3.94 x (1 {+-} 0.004) x 10{sup -25} MeV-b and S{sub hep}(0) = (8.6 {+-} 1.3) x 10{sup -20} keV-b. The dependence of the calculated S-factors on the momentum cutoff parameter {Lambda} has been examined for a physically reasonable range of {Lambda}. This dependence is found to be extremely small for the pp process, and to be within acceptable levels for the hep process, substantiating the consistency of our calculational scheme.

- Authors:

- Publication Date:

- Research Org.:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (US)

- Sponsoring Org.:
- USDOE Office of Energy Research (ER) (US)

- OSTI Identifier:
- 801033

- Report Number(s):
- JLAB-THY-02-36; nucl-th/0208055; KIAS P02049; Saclay T02/102

TRN: US0206201

- DOE Contract Number:
- AC05-84ER40150

- Resource Type:
- Journal Article

- Resource Relation:
- Other Information: No journal information given for this preprint; PBD: 1 Aug 2002

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ENANTIOMORPHS; MATRIX ELEMENTS; NUCLEAR PHYSICS; PERTURBATION THEORY; TRITIUM

### Citation Formats

```
T.S. Park, L.E. Marcucci, R. Schiavilla, M. Viviani, A. Kievsky, S. Rosati, K. Kubodera, D.P. Min, and M. Rho.
```*Parameter-free effective field theory calculation for the solar proton-fusion and hep processes*. United States: N. p., 2002.
Web.

```
T.S. Park, L.E. Marcucci, R. Schiavilla, M. Viviani, A. Kievsky, S. Rosati, K. Kubodera, D.P. Min, & M. Rho.
```*Parameter-free effective field theory calculation for the solar proton-fusion and hep processes*. United States.

```
T.S. Park, L.E. Marcucci, R. Schiavilla, M. Viviani, A. Kievsky, S. Rosati, K. Kubodera, D.P. Min, and M. Rho. Thu .
"Parameter-free effective field theory calculation for the solar proton-fusion and hep processes". United States. https://www.osti.gov/servlets/purl/801033.
```

```
@article{osti_801033,
```

title = {Parameter-free effective field theory calculation for the solar proton-fusion and hep processes},

author = {T.S. Park and L.E. Marcucci and R. Schiavilla and M. Viviani and A. Kievsky and S. Rosati and K. Kubodera and D.P. Min and M. Rho},

abstractNote = {Spurred by the recent complete determination of the weak currents in two-nucleon systems up to {Omicron}(Q{sup 3}) in heavy-baryon chiral perturbation theory, we carry out a parameter-free calculation of the threshold S-factors for the solar pp (proton-fusion) and hep processes in an effective field theory that combines the merits of the standard nuclear physics method and systematic chiral expansion. The power of the EFT adopted here is that one can correlate in a unified formalism the weak-current matrix elements of two-, three- and four-nucleon systems. Using the tritium {beta}-decay rate as an input to fix the only unknown parameter in the theory, we can evaluate the threshold S factors with drastically improved precision; the results are S{sub pp}(0) = 3.94 x (1 {+-} 0.004) x 10{sup -25} MeV-b and S{sub hep}(0) = (8.6 {+-} 1.3) x 10{sup -20} keV-b. The dependence of the calculated S-factors on the momentum cutoff parameter {Lambda} has been examined for a physically reasonable range of {Lambda}. This dependence is found to be extremely small for the pp process, and to be within acceptable levels for the hep process, substantiating the consistency of our calculational scheme.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2002},

month = {8}

}