Amplitude analysis and branching fraction measurement of B+ → D∗−D+ s π + decays

Abstract

The decays of the B+ meson to the fnal state D∗−D+ s π + are studied in protonproton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb−1 . The ratio of branching fractions of the B+ → D∗−D+ s π + and B0 → D∗−D+ s decays is measured to be 0.173 ± 0.006 ± 0.010, where the frst uncertainty is statistical and the second is systematic. Using partially reconstructed D∗+ s → D+ s γ and D+ s π 0 decays, the ratio of branching fractions between the B+ → D∗−D∗+ s π + and B+ → D∗−D+ s π + decays is determined as 1.31 ± 0.07 ± 0.14. An amplitude analysis of the B+ → D∗−D+ s π + decay is performed for the frst time, revealing dominant contributions from known excited charm resonances decaying to the D∗−π + fnal state. No signifcant evidence of exotic contributions in the D+ s π + or D∗−D+ s channels is found. The ft fraction of the scalar state T ∗ cs¯0 (2900)++ observed in the B+ → D−D+ s π + decay is determined to be less than 2.3% at a 90% confdence level.