Measurement of the lifetimes of promptly produced <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si22.svg"> <mml:msubsup> <mml:mi mathvariant="normal">Ω</mml:mi> <mml:mi>c</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si23.svg"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">Ξ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>c</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> baryons
R. Aaij
Abstract
A measurement of the lifetimes of the Ω c 0 and Ξ c 0 baryons is reported using proton–proton collision data at a centre-of-mass energy of 13 TeV , corresponding to an integrated luminosity of 5 . 4 fb - 1 collected by the LHCb experiment. The Ω c 0 and Ξ c 0 baryons are produced directly from proton interactions and reconstructed in the pK - K - π + final state. The Ω c 0 lifetime is measured to be 276.5 ± 13.4 ± 4.4 ± 0.7 fs , and the Ξ c 0 lifetime is measured to be 148 . 0 ± 2 . 3 ± 2 . 2 ± 0 . 2 fs , where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty on the D 0 lifetime. These results confirm previous LHCb measurements based on semileptonic beauty-hadron decays, which disagree with earlier results of a four times shorter Ω c 0 lifetime, and provide the single most precise measurement of the Ω c 0 lifetime.