BtoVVana: the package for analysis of Bs0→J/ψϕ and Bd0→J/ψK∗ decays

C++ package BtoVVana is aimed to extract physics parameters in decays of the scalar neutral B-meson to two vector particles in the intermediate state, and two leptons and two pseudoscalar mesons in the final state. An improved angular moments method is implemented in the package BtoVVana: the method uses the time dependent weighting functions and time-integrated observables with variable upper time limit. These observables allow to keep full time informative contents of the decay. By using the package BtoVVana it was shown that the statistical errors of extraction of the observables strongly depends on the choice of the angular weighting functions. The first version of the program contains algorithms to extract physics parameters in the case of untagged decays. The package BtoVVana and program codes for the channels Bs0→J/ψϕ and Bd0→J/ψK∗ in the Monte Carlo generator SIMUB were written in parallel and mutually tested with high precision.Program summaryTitle of the program: BtoVVanaCatalogue identifier: ADXE−v1−0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXE_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandComputer: PC, two Intel 2.0 GHz processors, 512 MB RAMOperating system: Linux Red Hat 6.1, 7.2, 7.3 and other platforms which allow to set ROOT packageProgramming language used: C++: gcc 2.96 or 2.95.2 compiler suite with g++Size of the package: 2.3 MB (0.4 MB compressed distribution archive), without ROOT libraries (additional 120 MB) and without input files with eventsDistribution format: tar gzip fileAdditional disk space required: Depends on the number of events: 35 MB for 100 000 events (output of SIMUB generator)No. of lines in distributed program, including test data, etc.:172 788No. of bytes in distributed program, including test data, etc.:42 213 507Nature of the physical problem: The package BtoVVana has been developed to study the performance of the angular moments method of the ΔΓ   determination from analysis of untagged decays Bs0→J/ψ(→μ+μ−)ϕ(→K+K−). By using the package BtoVVana it was shown that the method of angular moments gives stable results and is found to be an efficient and flexible tool for measurements with Bs0→J/ψϕ and Bd0→J/ψK∗ decays.Method of solution: The method of angular moments allows the construction of a sequential chain of extraction of the physics parameters from events: ΔΓ   → initial transversity amplitudes → weak CP-violating phase → strong CP-conserving phases →ΔMs→ΔMs. The standard angular moments method was improved by using the time dependent weighting function and time-integrated observables with variable upper time limit. These observables allow one to keep the full time information contents of the decay. This is the method is used in the package BtoVVana. It was shown that the statistical errors of extraction of the observables strongly depends on the choice of the angular weighting functions. The best weighting functions were found and implemented in the package BtoVVana. The program BtoVVana includes methods of extractions of observables as independent modules. Within the framework of the package BtoVVana user can include new analysis modules. The package BtoVVana and program codes for the channels Bs0→J/ψϕ and Bd0→J/ψK∗ in the Monte Carlo generator SIMUB were written in parallel and mutually tested with high precision.Restrictions on the complexity of the problem:   Program processes any number of files with any number of events; program tested with about 200 files including 2×1062×106 events.Typical running time: On a PC/Linux with 2.0 GHz processors BtoVVana package spends 15 s for every 100 000 events.