Physicists find possible cracks in the Standard Model of particle physics
Researchers analyzing billions of particle collisions have detected anomalies in rare particle decay patterns that deviate from established physics theory—but not by enough to confirm new physics yet. The findings, based on the largest dataset available, could signal undiscovered particles or forces, with implications for fundamental physics research and long-term technology development.
Originaltitel: Determination of short- and long-distance contributions in B<sup>0</sup> → K<sup>*0</sup>μ<sup>+</sup>μ<sup>-</sup> decays
<p>An amplitude analysis of the B<sup>0</sup> → K-*0 μ<sup>+</sup>μ<sup>-</sup> decay is presented. The analysis is based on data collected by the LHCb experiment from proton-proton collisions at √s = 7, 8 and 13 TeV, corresponding to an integrated luminosity of 4.7 fb<sup>-1</sup>. For the first time, Wilson coefficients and nonlocal hadronic contributions are accessed directly from the unbinned data, where the latter are parametrized as a function of q<sup>2</sup> with a polynomial expansion. Wilson coefficients and nonlocal hadronic parameters are determined under two alternative hypotheses: the first relies on experimental information alone, while the second one includes information from theoretical predictions for the nonlocal contributions. Both models obtain similar results for the parameters of interest. The overall level of compatibility with the Standard Model is evaluated to be between 1.8 and 1.9 standard deviations when looking at the <em>C</em><sub>9</sub> Wilson coefficient alone, and between 1.3 and 1.4 standard deviations when considering the full set of <em>C</em><sub>9,</sub> <em>C</em><sub>10,</sub> <em>C'</em><sub>9</sub> and <em>C'</em><sub>10</sub> Wilson coefficients. The ranges reflect the theoretical assumptions made in the analysis.</p>