English

Study of multi-neutron emission in the $\beta$-decay of $^{11}$Li

Nuclear Experiment 2020-11-25 v1

Abstract

The kinematics of two-neutron emission following the β\beta-decay of 11^{11}Li was investigated for the first time by detecting the two neutrons in coincidence and by measuring their angle and energy. An array of liquid-scintillator neutron detectors was used to reject cosmic-ray and γ\gamma-ray backgrounds by pulse-shape discrimination. Cross-talk events in which two detectors are fired by a single neutron were rejected using a filter tested on the β\beta-1n emitter 9^9Li. A large cross-talk rejection rate is obtained (>95%> 95 \%) over most of the energy range of interest. Application to 11^{11}Li data leads to a significant number of events interpreted as β\beta-2n decay. A discrete neutron line at \approx 2 MeV indicates sequential two-neutron emission, possibly from the unbound state at 10.6 MeV excitation energy in 11^{11}Be.

Keywords

Cite

@article{arxiv.1906.04699,
  title  = {Study of multi-neutron emission in the $\beta$-decay of $^{11}$Li},
  author = {F. Delaunay and N. L. Achouri and A. Algora and M. Assié and J. Balibrea and K. Banerjee and C. Bhattacharya and M. J. G. Borge and D. Cano-Ott and B. Fernández-Domínguez and L. M. Fraile and J. Gibelin and M. V. Lund and M. Madurga and F. M. Marqués and I. Marroquin and T. Martínez and E. Mendoza and N. A. Orr and M. Pârlog and X. Pereira-López and V. Pestel and K. Riisager and C. Santos and M. Sénoville and O. Tengblad and V. Vedia},
  journal= {arXiv preprint arXiv:1906.04699},
  year   = {2020}
}

Comments

4 pages, Proceedings of the EuNPC2018 Conference