Polarized radiative capture studies of the 3-body system below 80 keV
✍ Scribed by Henry R. Weller
- Book ID
- 104336860
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 293 KB
- Volume
- 631
- Category
- Article
- ISSN
- 0375-9474
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✦ Synopsis
Advances in both experimental and theoretical techniques are now making it possible to study three-body capture reactions below 80 keV in considerable detail. Measurements of the energy dependence of the cross section for the D(p,~,)3He reaction below 80 keV indicate an astrophysical S-factor which is 34% smaller than the "accepted" value. 1 Furthermore, our detailed measurements 1 of cross section, vector and tensor analyzing powers (obtained using the p(d,'y)3He reaction), and gamma-ray polarizations as a function of energy and angle have been compared to the results of new 3-body calculations by Viviani et al. 2 which include Coulomb, MEC and A-isobar effects. Dramatic effects of the tensor force and the associated two-body currents are observed in the analyzing power data for the first time. We have recently measured the vector analyzing power for the p(d,T)3He reaction. This observable is very sensitive to the presence of MECs, changing from -0.13 to -0.01 at 90 °, for example, when MEC effects are and are not included in the calculations, respectively. New precision measurements of tensor analyzing power (T20(90°)) have been used to extract the value of the aymptotic D-to-S state ratio for 3He, taking advantage of the asymptotic nature of the capture reaction at these low energies. 3 Presently, the discrepancies between state-of-the-art calculations and our data are significant, suggesting that additional physics, such as 3-body current effects, need to be taken into account.