Precision Measurements of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>Λ</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">c</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">D</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Lifetimes

We report new precision measurements of the lifetimes of the ${\ensuremath{\Lambda}}_{c}^{+}$ and ${D}^{0}$ from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 ${\ensuremath{\Lambda}}_{c}^{+}$ and 10 210 ${D}^{0}$ decays we observe lifetimes of $\ensuremath{\tau}[{\ensuremath{\Lambda}}_{c}^{+}]\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}198.1\ifmmode\pm\else\textpm\fi{}7.0\ifmmode\pm\else\textpm\fi{}5.6\mathrm{fs}$ and $\ensuremath{\tau}[{D}^{0}]\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}407.9\ifmmode\pm\else\textpm\fi{}6.0\ifmmode\pm\else\textpm\fi{}4.3\mathrm{fs}$.