@article{prior_spraker_amthor_keeter_nelson_sabourov_sabourov_tonchev_ahmed_kelley_et al._2004, title={Energy dependence of the astrophysical S factor for the Li-6(p, gamma)Be-7 reaction}, volume={70}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.70.055801}, abstractNote={Polarized proton beams with energies from 80 to 130 keV have been used to determine the slope of the astrophysical S factor for the {sup 6}Li(p,{gamma}{sub 0}){sup 7}Be and {sup 6}Li(p,{gamma}{sub 1}){sup 7}Be reactions. The slope was determined from the relative yields at five incident proton energies. The slope of the S factor was found to be negative. The analyzing power measurements indicate that the reaction proceeds predominately by s-wave capture. The negative slope does not appear to be due to low-binding-energy effects, the effects of nearby resonances, or electron screening of the nuclei. A resonating group model calculation demonstrates a new mechanism for producing a negative slope at astrophysically relevant energies in radiative capture reactions.}, number={5}, journal={PHYSICAL REVIEW C}, author={Prior, RM and Spraker, MC and Amthor, AM and Keeter, KJ and Nelson, SO and Sabourov, A and Sabourov, K and Tonchev, A and Ahmed, M and Kelley, JH and et al.}, year={2004}, month={Nov} }
 @misc{tilley_kelley_godwin_millener_purcell_sheu_weller_2004, title={Energy levels of light nuclei A=8, 9, 10}, volume={745}, ISSN={["1873-1554"]}, DOI={10.1016/j.nuclphysa.2004.09.059}, abstractNote={A review of the evidence on the properties of the nuclei A=8, 9 and 10, with emphasis on material leading to information about the structure of the A=8,9,10 systems.}, number={3-4}, journal={NUCLEAR PHYSICS A}, author={Tilley, DR and Kelley, JH and Godwin, JL and Millener, DJ and Purcell, JE and Sheu, CG and Weller, HR}, year={2004}, month={Dec}, pages={155–362} }
 @misc{tilley_cheves_godwin_hale_hofmann_kelley_sheu_weller_2002, title={Energy levels of light nuclei A=5, 6, 7}, volume={708}, ISSN={["1873-1554"]}, DOI={10.1016/S0375-9474(02)00597-3}, abstractNote={A review of the evidence on the properties of the nuclei A=5, 6 and 7, with emphasis on material leading to information about the structure of the A=5, 6, 7 systems. (References closed 23 August 2001.)}, number={1-2}, journal={NUCLEAR PHYSICS A}, author={Tilley, DR and Cheves, CM and Godwin, JL and Hale, GM and Hofmann, HM and Kelley, JH and Sheu, CG and Weller, HR}, year={2002}, month={Sep}, pages={3–163} }
 @article{canon_nelson_sabourov_wulf_weller_prior_spraker_kelley_tilley_2002, title={H-3((p)over-right-arrow,gamma)He-4 reaction below E-p=80 keV}, volume={65}, number={4}, journal={Physical Review. C, Nuclear Physics}, author={Canon, R. S. and Nelson, S. O. and Sabourov, K. and Wulf, E. and Weller, H. R. and Prior, R. M. and Spraker, M. and Kelley, J. H. and Tilley, D. R.}, year={2002}, pages={044008–1} }
 @article{nesaraja_brune_crowley_kelley_nelson_prior_sabourov_tilley_tonchev_weller_2001, title={Ratio of S factors for (p,gamma) reactions on C-12 and C-13 at astrophysically relevant energies - art. no. 065804}, volume={6406}, number={6}, journal={Physical Review. C, Nuclear Physics}, author={Nesaraja, C. D. and Brune, C. R. and Crowley, B. T. and Kelley, J. H. and Nelson, S. O. and Prior, R. M. and Sabourov, K. and Tilley, D. R. and Tonchev, A. and Weller, H. R.}, year={2001}, pages={5804-} }
 @article{kelley_canon_gaff_prior_rice_schreiber_spraker_tilley_wulf_weller_2000, title={The B-11((p)over-right-arrow, gamma)C-12 reaction below 100 keV}, volume={62}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.62.025803}, abstractNote={The ${}^{11}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{p},\ensuremath{\gamma}{)}^{12}\mathrm{C}$ reaction was studied by measuring the $\ensuremath{\gamma}$ rays that were produced when 80--100-keV polarized protons were stopped in a thick ${}^{11}\mathrm{B}$ target. Cross sections and vector analyzing powers at $90\ifmmode^\circ\else\textdegree\fi{}$ were determined as a function of energy for capture to the ground and first excited states of ${}^{12}\mathrm{C}.$ These analyzing powers are particularly sensitive to the interference between s- and p-wave contributions, and to the relative phase between direct and resonance amplitudes. The results were used to produce a reliable extrapolation of the astrophysical S factor at 0 keV by means of a direct-capture-plus-resonances model calculation. The value of $S(0)$ that was obtained for ${}^{11}\mathrm{B}(p,{\ensuremath{\gamma}}_{0}),$ $1.8\ifmmode\pm\else\textpm\fi{}0.4 \mathrm{keV}\mathrm{}\mathrm{b},$ is in agreement with previously determined values, but for ${}^{11}\mathrm{B}(p,{\ensuremath{\gamma}}_{1})$ the value of $S(0)$ is $3.5\ifmmode\pm\else\textpm\fi{}0.6 \mathrm{keV}\mathrm{}\mathrm{b}$ and is more than twice as large as previously determined values.}, number={2}, journal={PHYSICAL REVIEW C}, author={Kelley, JH and Canon, RS and Gaff, SJ and Prior, RM and Rice, BJ and Schreiber, EC and Spraker, M and Tilley, DR and Wulf, EA and Weller, HR}, year={2000}, month={Aug} }
 @article{wulf_canon_gaff_kelley_prior_schreiber_spraker_tilley_weller_viviani_et al._2000, title={New photodisintegration threshold observable in He-3}, volume={61}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.61.021601}, abstractNote={Measurements of the cross section, vector and tensor analyzing powers, and linear gamma-ray polarization in the radiative capture reactions D(p,{gamma}){sup 3}He and p(d,{gamma}){sup 3}He at c.m. energies in the range 0-53 keV allow the determination of the reduced matrix elements (RMEs) relevant for these transitions. From these RMEs the value of the integral which determines the Gerasimov-Drell-Hearn sum rule for {sup 3}He is obtained in the threshold region, corresponding to two-body breakup, and compared with the results of an ab initio microscopic three-body model calculation. The theoretical predictions for the value of this integral based on a ''nucleons-only'' assumption are an order of magnitude smaller than experiment. The discrepancy is reduced to about a factor of 2 when two-body currents are taken into account. This factor of 2 is due to an almost exact cancellation between the dominant E1 RMEs in the theoretical calculation. The excess E1 strength observed experimentally could provide useful insights into the nuclear interaction at low energies. (c) 1999 The American Physical Society.}, number={2}, journal={PHYSICAL REVIEW C}, author={Wulf, EA and Canon, RS and Gaff, SJ and Kelley, JH and Prior, RM and Schreiber, EC and Spraker, M and Tilley, DR and Weller, HR and Viviani, M and et al.}, year={2000}, month={Feb} }
 @article{spraker_prior_godwin_rice_wulf_kelley_tilley_weller_2000, title={Slope of the astrophysical S factor for the Li-7(p, gamma)Be-8 reaction}, volume={61}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.61.015802}, abstractNote={Polarized proton beams of 80 and 60 keV, and a biased target have been used to determine the slope of the astrophysical S factor for the ${}^{7}\mathrm{Li}(p,\ensuremath{\gamma}{)}^{8}\mathrm{Be}$ reaction from direct measurements at proton energies from 40 to 100 keV for capture to both the ground and the first excited states of ${}^{8}\mathrm{Be}.$ The results indicate a negativeslope for both cases. Vector analyzing power measurements at $90\ifmmode^\circ\else\textdegree\fi{}$ were also obtained for proton energies from 40 to 80 keV. It is shown that the negative slope can be accounted for by considering the effect of the subthreshold resonance state at 16.6 MeV if the capture into this weakly bound, subthreshold state occurs at an effective radius of about 46 fm. The effect of this state increases the extrapolated value of the S factor at ${E}_{p}=0$ from the previous value of 0.3 keV b to the present value of 0.50 keV b.}, number={1}, journal={PHYSICAL REVIEW C}, author={Spraker, M and Prior, RM and Godwin, MA and Rice, BJ and Wulf, EA and Kelley, JH and Tilley, DR and Weller, HR}, year={2000}, month={Jan} }
 @article{gaff_canon_kelley_nelson_sabourov_schreiber_tilley_weller_wulf_1999, title={Spin parity of the 7.478 MeV state of B-10 and the S factor of the Be-9((p)over-right-arrow,gamma(0))B-10 reaction}, volume={59}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.59.3425}, abstractNote={Polarized protons were used to measure the analyzing power of $\mathrm{the}{}^{9}\mathrm{Be}(\stackrel{\ensuremath{\rightarrow}}{p},\ensuremath{\gamma}{)}^{10}\mathrm{B}$ reaction for ${E}_{p}=280--0 \mathrm{keV}.$ The analyzing power for the ground state transition compared to calculations leads to a spin-parity assignment of ${2}^{+}$ for the 7.478 MeV state of ${}^{10}\mathrm{B}.$ This ${2}^{+}$ assignment is consistent with other observables for this reaction and is predicted by cluster and shell model calculations. It is found that the ${2}^{+}$ assignment leads to a value for the astrophysical S factor for capture to the ground state of ${}^{10}\mathrm{B}$ of $S(0)=0.20 \mathrm{keV}\mathrm{}\mathrm{b}$ which is about 40% smaller than that obtained with a ${2}^{\ensuremath{-}}$ assignment.}, number={6}, journal={PHYSICAL REVIEW C}, author={Gaff, SJ and Canon, RS and Kelley, JH and Nelson, SO and Sabourov, K and Schreiber, EC and Tilley, DR and Weller, HR and Wulf, EA}, year={1999}, month={Jun}, pages={3425–3428} }
 @article{wulf_godwin_guillemette_laymon_prior_rice_spraker_tilley_weller_1998, title={Astrophysical S factors for the Be-9((p)over-right-arrow,gamma)B-10 reaction}, volume={58}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.58.517}, abstractNote={Analyzing powers for the {sup 9}Be({rvec p},{gamma}){sup 10}B reaction were measured by stopping a 100 keV polarized proton beam in a {sup 9}Be target. The measured vector analyzing power is A{sub y}(90{degree})=0.18{plus_minus}0.03 for capture to the ground state, with smaller values at 90{degree} for the first three excited states. Astrophysical S factors were calculated for each of the final states using a direct capture plus resonance model which fit both the present analyzing power data and the previously reported cross section data. The calculated S factors at E{sub p}=0 keV for capture to the ground state and first three excited states were 0.25, 0.34, 0.27, and 0.10 keV b, respectively, which are considerably smaller than previously reported. The observed analyzing powers are explained, within experimental uncertainty, as arising from the interference of the E1 direct capture amplitude with the tails of nearby p-wave and s-wave resonances. {copyright} {ital 1998} {ital The American Physical Society}}, number={1}, journal={PHYSICAL REVIEW C}, author={Wulf, EA and Godwin, MA and Guillemette, JF and Laymon, CM and Prior, RM and Rice, BJ and Spraker, M and Tilley, DR and Weller, HR}, year={1998}, month={Jul}, pages={517–523} }
 @misc{tilley_cheves_kelley_raman_weller_1998, title={Energy levels of light nuclei, A=20}, volume={636}, ISSN={["1873-1554"]}, DOI={10.1016/S0375-9474(98)00129-8}, abstractNote={Compilation of energy levels of A = 20 nuclei, with emphasis on the review of material leading to information about the structure of the A = 20 systems.}, number={3}, journal={NUCLEAR PHYSICS A}, author={Tilley, DR and Cheves, CM and Kelley, CH and Raman, S and Weller, HR}, year={1998}, month={Jun}, pages={249–364} }
 @article{rice_wulf_canon_kelley_prior_spraker_tilley_weller_1997, title={Direct determination of the doublet and quartet M1 cross sections in p-d radiative capture at near-thermal energies}, volume={56}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.56.r2917}, abstractNote={Data obtained from studies of the $p(d\ensuremath{\rightarrow},\ensuremath{\gamma}{)}^{3}\mathrm{He}$ and the $d(p\ensuremath{\rightarrow},\ensuremath{\gamma}{)}^{3}\mathrm{He}$ reactions have been used to extract the transition amplitudes corresponding to $S=1/2$ (doublet) and $S=3/2$ (quartet) $M1$ radiative capture. Protons (deuterons) of 40 keV (80 keV) were stopped in ${\mathrm{D}}_{2}\mathrm{O}$ $({\mathrm{H}}_{2}\mathrm{O})$ ice targets. Angular distributions of $\ensuremath{\sigma}$, ${A}_{y},$ ${T}_{20},$ ${P}_{\ensuremath{\gamma}}$, and ${\mathrm{iT}}_{11}$ were fit simultaneously in terms of the four possible $E1$ $p$-wave capture amplitudes and the two $(S=1/2$ and $3/2)$ possible $M1$ $s$-wave capture amplitudes. The results obtained at ${E}_{\mathrm{cm}}=23.3$ keV indicate that the $S=1/2$ $M1$ capture cross section is 13.77 $\ifmmode\pm\else\textpm\fi{}$ 0.66 nb, while the $S=3/2$ $M1$ capture cross section is 6.74 $\ifmmode\pm\else\textpm\fi{}$ 0.44 nb. These results agree with the predictions of a recent three-body theoretical calculation which includes two-body currents [e.g., meson-exchange currents (MEC's)]. They also agree with the previous experimental determination of the doublet and quartet fusion rates obtained using the Wolfenstein-Gerstein effect to vary the relative population of $S=1/2$ and $3/2$ nuclear spins in the $\ensuremath{\mu}$-$p$-$d$ molecule prior to fusion.}, number={6}, journal={PHYSICAL REVIEW C}, author={Rice, BJ and Wulf, EA and Canon, RS and Kelley, JH and Prior, RM and Spraker, M and Tilley, DR and Weller, HR}, year={1997}, month={Dec}, pages={R2917–R2919} }
 @article{godwin_laymon_prior_tilley_weller_1997, title={Li-7((p)over-right-arrow,gamma)Be-8 reaction at E-p=80-0 keV}, volume={56}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.56.1605}, abstractNote={The ${}^{7}\mathrm{Li}(p\ensuremath{\rightarrow},\ensuremath{\gamma}{)}^{8}\mathrm{Be}$ reaction has been studied in the laboratory energy range ${E}_{p}=80$--0 keV. The vector analyzing powers ${A}_{y}(\ensuremath{\theta})$ and the angular distributions of the cross section $d\ensuremath{\sigma}/d\ensuremath{\Omega}(\ensuremath{\theta})$ for capture to the ground, first-, and third-excited states are reported. Additionally, the absolute cross section ${\ensuremath{\sigma}}_{T}(E)$ and (equivalently) the astrophysical $S$ factor $S(E)$ have been measured for capture to the third-excited state. Calculations have been performed for all three transitions using the direct capture model to which the known nearby $M$1 resonances were added. While they predict the angular distribution observed for the cross section and analyzing power in the case of both the first and third-excited states of ${}^{8}$Be, they do not reproduce those for the ground state. These calculations predict negligible $M$1 strength below 80 keV for capture to the third-excited state ${(2}^{+}$, $T=0+1$, 16.6 MeV), and we therefore conclude that the extrapolation of the astrophysical $S$ factor for the ${}^{7}\mathrm{Be}(p,\ensuremath{\gamma}{)}^{8}\mathrm{B}$ reaction, which has been performed previously by assuming pure $E$1 capture, is valid with regard to the neglect of any significant $p$-wave capture strength.}, number={3}, journal={PHYSICAL REVIEW C}, author={Godwin, MA and Laymon, CM and Prior, RM and Tilley, DR and Weller, HR}, year={1997}, month={Sep}, pages={1605–1612} }
 @article{schmid_rice_chasteler_godwin_kiang_kiang_laymon_prior_tilley_weller_1997, title={The H-2((p)over-right-arrow,gamma)He-3 and H-1((d)over-right-arrow,gamma)He-3 reactions below 80 keV}, volume={56}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.56.2565}, abstractNote={The details of a recent experimental study of the ${}^{2}\mathrm{H}(p\ensuremath{\rightarrow},\ensuremath{\gamma}{)}^{3}$He and the ${}^{1}\mathrm{H}(d\ensuremath{\rightarrow},\ensuremath{\gamma}{)}^{3}$He reactions for beam energies below 80 keV are discussed. In this study, both polarized and unpolarized incident beams were used to measure the cross section $\ensuremath{\sigma}(\ensuremath{\theta},E)$, the astrophysical $S$ factor $S(\ensuremath{\theta},E)$, the vector analyzing power ${A}_{y}(\ensuremath{\theta},E)$, and the tensor analyzing power ${T}_{20}(\ensuremath{\theta})$. In addition, the $\ensuremath{\gamma}$-ray linear polarization ${P}_{\ensuremath{\gamma}}(\ensuremath{\theta})$ was measured for an unpolarized incident beam. The experimental details of these measurements are discussed and the data are analyzed to obtain the amplitudes and phases of the contributing transition-matrix elements. The results of our measurements are compared with recent ab initio three-body theoretical calculations. This comparison reveals the large sensitivity of the polarization observables, especially the vector analyzing power ${(A}_{y})$, to the presence of meson-exchange current effects and indicates the need for further study. The tensor analyzing power data $[{T}_{20}(\ensuremath{\theta})$] are used to extract a value of the asymptotic $D$- to $S$-state ratio, $\ensuremath{\eta}$, for ${}^{3}$He.}, number={5}, journal={PHYSICAL REVIEW C}, author={Schmid, GJ and Rice, BJ and Chasteler, RM and Godwin, MA and Kiang, GC and Kiang, LL and Laymon, CM and Prior, RM and Tilley, DR and Weller, HR}, year={1997}, month={Nov}, pages={2565–2581} }