Blake T, Egede U, Owen P, Petridis K A, Pomery G
1University of Warwick, Coventry, UK.
2Imperial College London, London, UK.
Eur Phys J C Part Fields. 2018;78(6):453. doi: 10.1140/epjc/s10052-018-5937-3. Epub 2018 Jun 6.
A method for analysing the hadronic resonance contributions in decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving resonances, relative to the short-distance component, across the full dimuon mass spectrum of transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the spectrum provide a dramatic enhancement to -violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, , in the presence of new physics is presented.
提出了一种分析衰变中强子共振贡献的方法。该方法使用了一个经验模型，该模型依赖于对涉及共振的末态分支比和极化振幅的测量，相对于短程分量，跨越跃迁的整个双μ子质量谱。该模型与强子非局域效应的现有计算结果吻合良好。给出了这种贡献对角可观测量的影响，并展示了谱中的窄共振如何在短程振幅中显著增强违反的效应。最后，给出了在存在新物理的情况下，强子共振对轻子普适性比率的影响的研究。
