title Improved measurement of the half-life of the math mrow msup miJ/mi miπ/mi /msup mo=/mo msup mn8/mn mo−/mo /msup /mrow /math nuclear isomer math mmultiscripts mi mathvariant=”normal”Eu/mi mprescripts/ none/ mrow mn152/mn msub mim/mi mn2/mn /msub /mrow /mmultiscripts /math/title