Physicists find hints of unknown particles in rare particle decay
Researchers analyzing millions of particle collisions have detected anomalies in a rare decay process that could point to undiscovered physics beyond current theory. The findings, while not yet conclusive, suggest gaps in our fundamental understanding—the kind of breakthrough that could reshape physics and open new technology frontiers.
Originaltitel: Amplitude Analysis of the <em>B</em><sup>0</sup> → <em>K</em>*<sup>0</sup> μ<sup>+</sup>μ<sup>-</sup> Decay
<p>An amplitude analysis of the <em>B<sup>0</sup> → K<sup>*0</sup>μ<sup>+</sup>μ<sup>-</sup></em> decay is presented using a dataset corresponding to an integrated luminosity of 4.7 fb<sup>-1</sup> of <em>pp</em> collision data collected with the LHCb experiment. For the first time, the coefficients associated to short-distance physics effects, sensitive to processes beyond the standard model, are extracted directly from the data through a <em>q<sup>2</sup></em>-unbinned amplitude analysis, where <em>q<sup>2</sup></em> is the μ<sup>+</sup>μ<sup>-</sup> invariant mass squared. Long-distance contributions, which originate from nonfactorizable QCD processes, are systematically investigated, and the most accurate assessment to date of their impact on the physical observables is obtained. The pattern of measured corrections to the short-distance couplings is found to be consistent with previous analyses of <em>b-</em> to <em>s-</em>quark transitions, with the largest discrepancy from the standard model predictions found to be at the level of 1.8 standard deviations. The global significance of the observed differences in the decay is 1.4 standard deviations.</p>