# Angular moments of the decay Λ b 0  → Λ μ + μ − at low hadronic recoil

29 September 2018

Abstract: An analysis of the angular distribution of the decay Λ b 0  → Λ μ + μ − is presented, using data collected with the LHCb detector between 2011 and 2016 and corresponding to an integrated luminosity of approximately 5 fb −1 . Angular observables are determined using a moment analysis of the angular distribution at low hadronic recoil, corresponding to the dimuon invariant mass squared range 15 < q 2 < 20 GeV 2 / c 4 . The full basis of observables is measured for the first time. The lepton-side, hadron-side and combined forward-backward asymmetries of the decay are determined to be A F B ℓ = − 0.39 ± 0.04 stat ± 0.01 syst , A F B h = − 0.30 ± 0.05 stat ± 0.02 syst , A F B ℓ h = + 0.25 ± 0.04 stat ± 0.01 syst . $\begin{array}{l}{A}_{\mathrm{FB}}^{\ell }=-0.39\pm 0.04\left(\mathrm{stat}\right)\pm 0.01\left(\mathrm{syst}\right),\hfill \\ {}{A}_{\mathrm{FB}}^h=-0.30\pm 0.05\left(\mathrm{stat}\right)\pm 0.02\left(\mathrm{syst}\right),\hfill \\ {}{A}_{\mathrm{FB}}^{\ell h}=+0.25\pm 0.04\left(\mathrm{stat}\right)\pm 0.01\left(\mathrm{syst}\right).\hfill \end{array}$

Published in: JHEP 1809 (2018) 146