${\mathrm{\Lambda }}^{\ast }(1405)$-matter: stable or unstable?

A recent suggestion [PLB 774 (2017) 522] that purely-${\mathrm{\Lambda }}^{\ast }(1405)$ nuclei provide the absolute minimum energy in charge-neutral baryon matter for baryon-number $A\gtrsim 8$, is tested within RMF calculations. A broad range of ${\mathrm{\Lambda }}^{\ast }$ interaction strengths, commensurate with $(\bar K \bar K NN)_{I=0}$ binding energy assumed to be of order 100 MeV, is scanned. It is found that the binding energy per ${\mathrm{\Lambda }}^{\ast }$, $B\mathrm{/}A$, saturates for $A\gtrsim 120$ with values of $B\mathrm{/}A$ considerably below 100 MeV, implying that ${\mathrm{\Lambda }}^{\ast }(1405)$ matter is highly unstable against strong decay to $\mathrm{\Lambda }$ and $\mathrm{\Sigma }$ hyperon aggregates. The central density of ${\mathrm{\Lambda }}^{\ast }$ matter is found to saturate as well, at roughly twice nuclear matter density. Moreover, it is shown that the underlying very strong $\bar K N$potentials,fittedforisospin$I=0$tothemassandwidthvaluesof$\Lambda^{\ast}(1405)$, fail to reproduce values of single-nucleon absorption fractions deduced across the periodic table from $K^{-}$ capture-at-rest bubble chamber experiments.