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Partialy Paradoxist Smarandache Geometries
A paradoxist Smarandache geometry combines Euclidean, hyperbolic, and elliptic geometry into one space along with other non-Euclidean behaviors oflines that would seem to require a discrete space. A class of continuous spaces is presented here together with specific examples that emibit almost all of these phenomena and suggest the prospect of a continuous paradoxist geometry
Determination of S17 from 8B breakup by means of the method of continuum-discretized coupled-channels
The astrophysical factor for 7Be(p,\gamma)8B at zero energy, S17(0), is
determined from an analysis of 208Pb(8B, p+7Be)208Pb at 52 MeV/nucleon by means
of the method of continuum-discretized coupled-channels (CDCC) taking account
of all nuclear and Coulomb breakup processes. The asymptotic normalization
coefficient (ANC) method is used to extract S17(0) from the calculated
breakup-cross-section. The main result of the present paper is S17(0)=20.9
+2.0/-1.9 eV b. The error consists of 8.4% experimental systematic error and
the error due to the ambiguity in the s-wave p-7Be scattering length. This
value of S17(0) differs from the one extracted with the first-order
perturbation theory including Coulomb breakup by dipole transitions: 18.9 +/-
1.8 eV b. It turns out that the difference is due to the inclusion of the
nuclear and Coulomb-quadrupole transitions and multi-step processes of
all-order in the present work. The p-7Be interaction potential used in the CDCC
calculation is also used in the ANC analysis of 7Be(p,\gamma)8B. The value of
S17(0)=21.7 +0.62/-0.55 eV b obtained is consistent with the previous one
obtained from a precise measurement of the p-capture reaction cross section
extrapolated to zero incident energy, S17(0)=22.1 +/- 0.6 (expt) +/- 0.6 (theo)
eV b, where (theo) stands for the error in the extrapolation. Thus, the
agreement between the values of S17(0) obtained from direct 7Be(p,\gamma)8B and
indirect 8B-breakup measurements is significantly improved.Comment: 13 pages, 9 figures, published in PR
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