Probing the single-particle character of rotational states in 19^{19}F using a short-lived isomeric beam

A beam containing a substantial component of both the $J^{\pi}=5^+$, $T_{1/2}=162$ ns isomeric state of $^{18}$F and its $1^+$, 109.77-min ground state has been utilized to study members of the ground-state rotational band in $^{19}$F through the neutron transfer reaction $(d$,$p)$ in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13/2$^+$ band-terminating state. The agreement between shell-model calculations, using an interaction constructed within the $sd$ shell, and our experimental results reinforces the idea of a single-particle/collective duality in the descriptions of the structure of atomic nuclei

Response to Letter Regarding Article, "Hypertrophic Cardiomyopathy Is Predominantly a Disease of Left Ventricular Outflow Tract Obstruction"

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Measurement of F 17 (d,n) Ne 18 and the impact on the F 17 (p,γ) Ne 18 reaction rate for astrophysics

Background: The F17(p,γ)Ne18 reaction is part of the astrophysical hot CNO cycles that are important in astrophysical environments like novas. Its thermal reaction rate is low owing to the relatively high energy of the resonances and therefore is dominated by direct, nonresonant capture in stellar environments at temperatures below 0.4 GK. Purpose: An experimental method is established to extract the proton strength to bound and unbound states in experiments with radioactive ion beams and to determine the parameters of direct and resonant capture in the F17(p,γ)Ne18 reaction. Method: The F17(d,n)Ne18 reaction is measured in inverse kinematics using a beam of the short-lived isotope F17 and a compact setup of neutron, proton, γ-ray, and heavy-ion detectors called resoneut. Results: The spectroscopic factors for the lowest l=0 proton resonances at Ec.m.=0.60 and 1.17 MeV are determined, yielding results consistent within 1.4σ of previous proton elastic-scattering measurements. The asymptotic normalization coefficients of the bound 21+ and 22+ states in Ne18 are determined and the resulting direct-capture reaction rates are extracted. Conclusions: The direct-capture component of the F17(p,γ)Ne18 reaction is determined for the first time from experimental data on Ne18

Experimental Investigation of the Ne 19 (p,γ)20Na Reaction Rate and Implications for Breakout from the Hot CNO Cycle

The Ne19(p,γ)Na20 reaction is the second step of a reaction chain which breaks out from the hot CNO cycle, following the O15(α,γ)Ne19 reaction at the onset of x-ray burst events. We investigate the spectrum of the lowest proton-unbound states in Na20 in an effort to resolve contradictions in spin-parity assignments and extract reliable information about the thermal reaction rate. The proton-transfer reaction Ne19(d,n)Na20 is measured with a beam of the radioactive isotope Ne19 at an energy around the Coulomb barrier and in inverse kinematics. We observe three proton resonances with the Ne19 ground state, at 0.44, 0.66, and 0.82 MeV c.m. energies, which are assigned 3+, 1+, and (0+), respectively. In addition, we identify two resonances with the first excited state in Ne19, one at 0.20 MeV and one, tentatively, at 0.54 MeV. These observations allow us for the first time to experimentally quantify the astrophysical reaction rate on an excited nuclear state. Our experiment shows an efficient path for thermal proton capture in Ne19(p,γ)Na20, which proceeds through ground state and excited-state capture in almost equal parts and eliminates the possibility for this reaction to create a bottleneck in the breakout from the hot CNO cycle