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Observation of a Near-Threshold Proton Resonance in ^{11}B
E Lopez-Saavedra1, S Almaraz-Calderon1, B W Asher1
1Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
Physical Review Letters
|July 16, 2022
Summary
Researchers observed a near-threshold proton resonance in Boron-11 (¹¹B) using a radioactive Beryllium-10 (¹⁰Be) beam. This finding aids in understanding the beta-delayed proton decay of ¹¹Be.
Area of Science:
- Nuclear Physics
- Radioactive Ion Beam Physics
Background:
- Investigating exotic nuclei like Beryllium-10 (¹⁰Be) and Boron-11 (¹¹B) is crucial for understanding nuclear structure.
- Beta-delayed proton decay provides insights into nuclear astrophysics and the properties of unstable nuclei.
Purpose of the Study:
- To identify and characterize a near-threshold proton resonance in ¹¹B.
- To investigate the role of this resonance in the beta-delayed proton decay of ¹¹Be.
- To study quantum near-threshold many-body dynamics of unstable nuclear states.
Main Methods:
- Utilized inverse kinematics with a radioactive ¹⁰Be beam.
- Measured the reaction ¹⁰Be(d,n)¹¹Be, leading to ¹¹B states decaying via proton emission.
- Performed distorted wave Born approximation (DWBA) calculations.
Main Results:
- Observed a proton resonance in ¹¹B at an excitation energy of 11.44 ± 0.04 MeV.
- Determined the resonance energy to be 211(40) keV, consistent with previous observations.
- Extracted a spectroscopic factor of 0.27(6) and assigned a tentative ℓ=0 character.
Conclusions:
- The observed state exhibits threshold-resonance characteristics, crucial for studying quantum near-threshold dynamics.
- This finding is a significant step toward explaining the large beta-delayed proton-decay branch of ¹¹Be.
- The study provides an ideal case for exploring many-body dynamics in unstable nuclear systems.
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