Study of the rare decays of B0s and B0 mesons into muon pairs using data collected during 2015 and 2016 with the ATLAS detector Aaboud, M. Aguilar Saavedra, Juan Antonio Atlas Collaboration A study of the decays B0s→μ+μ− and B0→μ+μ− has been performed using 26.3 fb−1 of 13 TeV LHC proton-proton collision data collected with the ATLAS detector in 2015 and 2016. Since the detector resolution in μ+μ− invariant mass is comparable to the B0s-B0 mass difference, a single fit determines the signal yields for both decay modes. This results in a measurement of the branching fraction B(B0s→μ+μ−)=(3.2+1.1−1.0)×10−9 and an upper limit B(B0→μ+μ−)<4.3×10−10 at 95% confidence level. The result is combined with the Run 1 ATLAS result, yielding B(B0s→μ+μ−)=(2.8+0.8−0.7)×10−9 and B(B0→μ+μ−)<2.1×10−10 at 95% confidence level. The combined result is consistent with the Standard Model prediction within 2.4 standard deviations in the B(B0→μ+μ−)-B(B0s→μ+μ−) plane. 2020-03-05T09:05:49Z 2020-03-05T09:05:49Z 2019-04-15 journal article Álvarez Piqueras, D., Aparisi, P., Bailey, A. J., Barranco, L., Cabrera, S., Castillo, F. L., ... & Estrada, O. (2019). Study of the rare decays of B s 0 and B 0 mesons into muon pairs using data collected during 2015 and 2016 with the ATLAS detector. http://hdl.handle.net/10481/60021 10.1007/JHEP04(2019)098 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Springer Nature