Physicists map rare particle decay, finding no exotic matter
Researchers at CERN analyzed millions of particle collisions to measure how B mesons decay into other particles—a rare process that tests physics theories. The precision measurements, published in the Journal of High Energy Physics, reveal the decay follows expected patterns, constraining theories about exotic matter that could reshape fundamental physics.
Originaltitel: Amplitude analysis and branching fraction measurement of <em>B</em><sup>+</sup> â <em>D</em>*<sup>-</sup><em>D<sub>s</sub></em><sup>+</sup>Ï<sup>+</sup> decays
<p>The decays of the B+ meson to the final state D*D--(s)+pi(+) are studied in proton-proton 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-Ds+pi(+) and B-0 -> D*D--(s)+ decays is measured to be 0.173 +/- 0.006 +/- 0.010, where the first uncertainty is statistical and the second is systematic. Using partially reconstructed D-s*(+) -> D-s*(+)gamma and D-s(+)pi(0) decays, the ratio of branching fractions between the B+ -> D*D--(s)*(+)pi(+) and B+ -> D*D--(s)+pi(+) decays is determined as 1.31 +/- 0.07 +/- 0.14. An amplitude analysis of the B+ -> D*D--(s)+pi(+) decay is performed for the first time, revealing dominant contributions from known excited charm resonances decaying to the D*(-)pi(+) final state. No significant evidence of exotic contributions in the D-s(+)pi(+) or D*D--(s)+ channels is found. The fit fraction of the scalar state T*(c (s) over bar0) (2900)(++) observed in the B+ -> D-Ds+pi(+) decay is determined to be less than 2.3% at a 90% confidence level.</p>