Single-Proton Removal Reaction Study of 16B

TL;DR

This study investigates the unbound nucleus 16B through single-proton removal from 17C, revealing a narrow resonance near threshold with implications for its level structure and decay modes.

Contribution

The paper provides the first detailed experimental analysis of 16B's low-lying states using in-flight decay detection and identifies a narrow resonance with specific nuclear configurations.

Findings

Identified a narrow resonance at 85 keV above threshold.

Suggested a dominant decay configuration involving specific proton and neutron orbitals.

Revealed a very narrow width, indicating a potentially unresolved multiplet.

Abstract

The low-lying level structure of the unbound system $^{16}$B has been investigated via single-proton removal from a 35 MeV/nucleon $^{17}$C beam. The coincident detection of the beam velocity $^{15}$B fragment and neutron allowed the relative energy of the in-flight decay of $^{16}$B to be reconstructed. The resulting spectrum exhibited a narrow peak some 85 keV above threshold. It is argued that this feature corresponds to a very narrow ($\Gamma \ll $100 keV) resonance, or an unresolved multiplet, with a dominant $\pi (p_{3/2})^{-1} \otimes \nu (d_{5/2}^3)_{J=3/2^+}$ + $\pi (p_{3/2})^{-1} \otimes \nu (d_{5/2}^2,s_{1/2})_{J=3/2^+}$ configuration which decays by d-wave neutron emission.