The decay anti-B0s → J/ψ π+ π− can be exploited to study CP violation. A detailed understanding of its structure is imperative in order to optimize its usefulness. An analysis of this three-body final state is performed using a 1.0 fb^−1 sample of data produced in 7 TeV pp collisions at the LHC and collected by the LHCb experiment. A modified Dalitz plot analysis of the final state is performed using both the invariant mass spectra and the decay angular distributions. The π+ π− system is shown to be dominantly in an S-wave state, and the CP-odd fraction in this anti-B0s decay is shown to be greater than 0.977 at 95% confidence level. In addition, we report the first measurement of the J/ψ π+ π− branching fraction relative to J/ψ ϕ of (19.79 ± 0.47 ± 0.52)%.
Analysis of the Resonant Components in anti-B0s → J/ψ π+ π−
CARBONE, ANGELO;GALLI, DOMENICO;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2012
Abstract
The decay anti-B0s → J/ψ π+ π− can be exploited to study CP violation. A detailed understanding of its structure is imperative in order to optimize its usefulness. An analysis of this three-body final state is performed using a 1.0 fb^−1 sample of data produced in 7 TeV pp collisions at the LHC and collected by the LHCb experiment. A modified Dalitz plot analysis of the final state is performed using both the invariant mass spectra and the decay angular distributions. The π+ π− system is shown to be dominantly in an S-wave state, and the CP-odd fraction in this anti-B0s decay is shown to be greater than 0.977 at 95% confidence level. In addition, we report the first measurement of the J/ψ π+ π− branching fraction relative to J/ψ ϕ of (19.79 ± 0.47 ± 0.52)%.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.