6533b7dafe1ef96bd126ebde

RESEARCH PRODUCT

Some remarks on the discovery of Md-244

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In two recent papers by Pore et al. and Khuyagbaatar et al., discovery of the new isotope $^{244}\mathrm{Md}$ was reported. The decay data, however, are conflicting. While Pore et al. report two isomeric states decaying by $\ensuremath{\alpha}$ emission with ${E}_{\ensuremath{\alpha}}(1)=8.66(2)\text{ }\text{ }\mathrm{MeV}$, ${T}_{1/2}(1)={0.4}_{\ensuremath{-}0.1}^{+0.4}\text{ }\text{ }\mathrm{s}$ and ${E}_{\ensuremath{\alpha}}(2)=8.31(2)\text{ }\text{ }\mathrm{MeV}$, ${T}_{1/2}(2)\ensuremath{\approx}6\text{ }\text{ }\text{ }\mathrm{s}$, Khuyagbaatar et al. [Phys. Rev. Lett. 125, 142504 (2020).] report only a single transition with a broad energy distribution of ${E}_{\ensuremath{\alpha}}=(8.73--8.86)\text{ }\text{ }\mathrm{MeV}$ and ${T}_{1/2}={0.30}_{\ensuremath{-}0.09}^{+0.19}\text{ }\text{ }\mathrm{s}$. The data published in Pore et al. are very similar to those published for $^{245m}\mathrm{Md}$ [${E}_{\ensuremath{\alpha}}=8.64(2)$, 8.68(2) MeV, ${T}_{1/2}={0.35}_{\ensuremath{-}0.16}^{+0.23}\text{ }\text{ }\mathrm{s}$ [V. Ninov, F. P. He\ss{}berger, S. Hofmann, H. Folger, G. M\"unzenberg, P. Armbruster, A. V. Yeremin, A. G. Popeko, M. Leino, and S. Saro, Z. Phys. A 356, 11 (1996).] ]. Therefore, we compare the data presented for $^{244}\mathrm{Md}$ in Pore et al. with those reported for $^{245}\mathrm{Md}$ in Ninov et al. and also in Khuyagbaatar et al. We conclude that the data presented in Pore et al. shall be attributed to $^{245}\mathrm{Md}$ with small contributions (one event each) from $^{245}\mathrm{Fm}$ and probably $^{246}\mathrm{Md}$.