The [Formula Presented] reaction at astrophysically relevant energies

The [Formula Presented] reaction was studied by detecting the [Formula Presented]-rays produced when 100-, 130-, and [Formula Presented] polarized protons were stopped in a thick [Formula Presented] target. Polarized and unpolarized incident beams were used to measure the cross section and vector analyzing power as a function of angle and energy for capture to the ground [Formula Presented], the second [Formula Presented], and the fifth [Formula Presented] excited states of [Formula Presented]. The data were analyzed to obtain the amplitudes and phases of the contributing transition-matrix elements at each measured energy for all three transitions. Values of the astrophysical [Formula Presented] factors were obtained from the cross section data and are compared to previous results. A direct capture plus resonance model calculation was performed in an attempt to account for all measured quantities. It was found that the large [Formula Presented] value of [Formula Presented] observed in the case of capture to the ground state could be accounted for by including the sub-threshold resonance at [Formula Presented]. © 2003 The American Physical Society.

Duke Scholars

Author John H Kelley Physics