We offer to your attention a preprint “The search for spontaneous fission from the ²⁵⁰No isomeric state via prompt neutron multiplicity distribution analysis” E7-2023-61 issued by the JINR Publishing Department. The authors are Roman Mukhin et al.

The complete fusion reaction ²⁰⁴Pb(⁴⁸Ca, 2n)²⁵⁰No was used to study two activities of ²⁵⁰No with distinct half-lives. A total of 1357 events were observed in the SFiNx neutron detection system. The study aimed to differentiate prompt neutron multiplicity distributions of ²⁵⁰No for the ground and the K-isomeric states. However, the distributions for both activities were indistinguishable according to statistical tests. The average number of neutrons emitted per spontaneous fission of ²⁵⁰No was determined to be 4.1 ± 0.1. Using the Tikhonov regularization method, a prompt multiplicity distribution was presented for the first time. Despite significant efforts, numerous questions about the ²⁵⁰No isotope remain, emphasizing the need for continued research.

The study has been performed at the Flerov Laboratory of Nuclear Reactions at JINR and submitted to Physical Review C.

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