Physicists Refine Rare Particle Decay Measurement with Record Precision
Researchers at CERN have measured how often a specific type of B particle decays into smaller particles with unprecedented accuracy, using nearly a decade of collision data. The result validates theoretical predictions about particle behavior and demonstrates the LHCb detector's ability to detect extremely rare events—a capability relevant to efforts to understand fundamental asymmetries in nature.
Originaltitel: Measurement of the branching fraction of B<sup>0</sup><em>â</em> J<em>/ÏÏ</em><sup>0</sup> decays
<p>The ratio of branching fractions between B-0 -> J/psi pi(0) and B+ -> J/psi K*+ decays is measured with proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb(-1). The measured value is B-B(0) -> -> J/psi pi(0)/B+ -> J/psi K*+ = (1.153 +/- 0.053 +/- 0.048) x 10-2, where the first uncertainty is statistical and the second is systematic. The branching fraction for B-0 -> J/psi pi(0) decays is determined using the branching fraction of the normalisation channel, resulting in B-B(0) -> J/psi pi(0) = (1.670 +/- 0.077 +/- 0.069 +/- 0.095) x 10-5, where the last uncertainty corresponds to that of the external input. This result is consistent with the current world average value and competitive with the most precise single measurement to date.</p>