arXiv:2603.12477: Data, efficiencies, resolutions, background lineshape and fraction for "Measurement of the local and nonlocal amplitudes in $B^{+}\to K^{+}μ^{+}μ^{-}$ decays"

This repository contains the necessary information required to analyse the data presented in arXiv:2603.12477 (LHCb-PAPER-2025-055).

When using this dataset, cite it as 

LHCb collaboration, R.~Aaij \textit{et al.}, Measurement of the local and nonlocal amplitudes in $B^{+}\to K^{+}μ^{+}μ^{-}$ decays, arXiv:2603.12477, data obtained from doi:10.5281/zenodo.19497184

In particular, the fully selected unbinned dimuon mass (dimuon_mass_mev) distribution in units of MeV/c^2 that appears in Fig.3 of LHCb-PAPER-2025-055 is presented in the file run1run2_dimuon_mass_LHCb-PAPER-2025-055_data.csv.

The file run1run2_dimuon_mass_LHCb-PAPER-2025-055_info.csv contains:

• The combinatorial background probability density function (bkg_model_lineshape) as a function of the invariant mass of the dimuon system (dimuon_mass_mev), along with the combinatorial background fraction (bkg_fraction) integrated across dimuon mass, as shown in Fig.3 of the paper. 
• The three efficiency corrections as a function of the invariant mass of the dimuon system, corresponding to the central values of the curves shown in Fig. 1 of the paper. Note that the relative normalisation between the various efficiency curves is fixed, but the overall normalisation is arbitrary, as it drops out once the decay rate is normalised over the dimuon-mass fit range.
  • dimuon_mass_efficiency_term_CAfplus, that multiplies the 1st term on the RHS of Eq. 2 
  • dimuon_mass_efficiency_term_CAfzero, that multiplies the 2nd term on the RHS of Eq. 2
  • dimuon_mass_efficiency_term_CVfplus, that multiplies the 3rd term on the RHS of Eq. 2
• The three resolution functions are shown as a function of the dimuon invariant mass for each of the three dimuon invariant mass regions specified in Table 2 of the paper.
  • dimuon_mass_resolution_region1, used for region-1 of the fit in Fig.3
  • dimuon_mass_resolution_region2, used for region-2 of the fit in Fig.3
  • dimuon_mass_resolution_region3, used for region-3 of the fit in Fig.3