New sub-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>μ</mml:mi></mml:mrow></mml:math>s isomers in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi/><mml:mrow><mml:mn>125</mml:mn><mml:mo>,</mml:mo><mml:mn>127</mml:mn><mml:mo>,</mml:mo><mml:mn>129</mml:mn></mml:mrow></mml:msup><mml:mi mathvariant="normal">Sn</mml:mi></mml:mrow></mml:math>and isomer systematics of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi/><mml:mrow><mml:mn>124</mml:mn><mml:mtext>−</mml:mtext><mml:mn>130</mml:mn></mml:mrow></mml:msup><mml:mi mathvariant="normal">Sn</mml:mi></mml:mrow></mml:math>

New sub-$\ensuremath{\mu}$s isomers have been observed in the neutron-rich Sn isotopes. ${}^{125,127,129}\mathrm{Sn}$ nuclei have been produced in a relativistic fission reaction of $^{238}\mathrm{U}$ on a $^{9}\mathrm{Be}$ target at 750 $A\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{MeV}$ and by the fragmentation of $^{136}\mathrm{Xe}$ at 600 $A\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{MeV}$ populating high-spin yrast states. In addition to the already known $\ensuremath{\mu}$s isomers, three new ones with sub-$\ensuremath{\mu}$s half-lives have been observed. These yrast isomers are the high-spin members of the $\ensuremath{\nu}({d}_{3/2}^{\ensuremath{-}1}{h}_{11/2}^{\ensuremath{-}2})$ and $\ensuremath{\nu}{h}_{11/2}^{\ensuremath{-}n}$, seniority $v=3$ multiplets leading to isomeric ($23/{2}^{+}$) and ($27/{2}^{\ensuremath{-}}$) states, respectively. Added to the already known $19/{2}^{+}\ensuremath{\mu}$s isomers in this region the current work completes the systematic information of neutron-hole excitations toward the filling of the last ${h}_{11/2}$ orbital at $N=82$. The results are discussed in the framework of state-of-the-art shell-model calculations using realistic interactions.

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