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arXiv · 2308.01171

Measurement of the $B_s^0 \to \mu\mu$ Effective Lifetime with the ATLAS Detector

ATLAS Collaboration
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Abstract

This paper reports the first ATLAS measurement of the $B_s^0 \to \mu\mu$ effective lifetime. The measurement is based on the data collected in 2015-2016, amounting to 26.3 fb$^{-1}$ of 13 TeV LHC proton-proton collisions. The proper decay-time distribution of $58\pm13$ background-subtracted signal candidates is fit with simulated signal templates parameterised as a function of the $B_s^0$ effective lifetime, with statistical uncertainties extracted through a Neyman construction. The resulting effective measurement of the $B_s^0 \to \mu\mu$ lifetime is $0.99^{+0.42}_{-0.07} \, (\text{stat.})\pm 0.17 \text{ (syst.)}\,\mathrm{ps}$ and it is found to be consistent with the Standard Model.

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ATLAS Collaboration. 2023-08-02. Measurement of the $B_s^0 \to \mu\mu$ Effective Lifetime with the ATLAS Detector. https://doi.org/10.1007/jhep09(2023)199

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