2003/08/05 by A. R. Junghans, A. Junghans, E. C. Mohrmann +11 · 2 citations
Physics and Astronomy · #Nuclear physics research studies #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-ex
paper · pdf · doi:10.1103/physrevc.68.065803
published as Phys.Rev.C68:065803,2003 · 22 pages, 20 figures
arxiv created 2003/08/05 · openalex publication_date 2003/12/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present new measurements of the 7Be(p,\ensuremathγ)8B cross section from Ec.m.=116 to 2460\phantom\rule0.3em0exkeV (where c.m. means center-of-mass), which incorporate several improvements over our previously published experiment, also discussed here. Our new measurements lead to S17(0)=22.1\ifmmode±\else\textpm\fi0.6(expt)\ifmmode±\else\textpm\fi0.6(theor)\phantom\rule0.3em0exeV\phantom\rule0.3em0exb based on data from Ec.m.=116 to 362\phantom\rule0.3em0exkeV, where the central value is based on the theory of Descouvemont and Baye. The theoretical error estimate is based on the fit of 12 different theories to our low-energy data. We compare our results to other S17(0) values extracted from both direct [7Be(p,\ensuremathγ)8B] and indirect (Coulomb-dissociation and heavy-ion reaction) measurements, and show that the results of these three types of experiments are not mutually compatible. We recommend a ``best'' value, S17(0)=21.4\ifmmode±\else\textpm\fi0.5(expt)\ifmmode±\else\textpm\fi0.6(theor)\phantom\rule0.3em0exeV\phantom\rule0.3em0exb, based on the mean of all modern direct measurements below the 1+ resonance. We also present S factors at 20\phantom\rule0.3em0exkeV which is near the center of the Gamow window: the result of our measurements is S17(20)=21.4\ifmmode±\else\textpm\fi0.6(expt)\ifmmode±\else\textpm\fi0.6(theor)\phantom\rule0.3em0exeV\phantom\rule0.3em0exb, and the recommended value is S17(20)=20.6\ifmmode±\else\textpm\fi0.5(expt)\ifmmode±\else\textpm\fi0.6(theor)\phantom\rule0.3em0exeV\phantom\rule0.3em0exb.