Role of Quantum-size Effects on the Dehydrogenation of CH4 on 3d TMn Clusters: DFT Calculations Combined with Data Mining

In this work, we report a theoretical investigation of the role of quantum-size effects (QSE) on the dehydrogenation of methane (CH4) on 3d transition-metal clusters, TMn , where TM =...

Electromagnetic finite-size effects beyond the point-like approximation

We present a model-independent and relativistic approach to analytically derive electromagnetic finite-size effects beyond the point-like approximation. The key element is the use of electromagnetic Ward identities to constrain vertex functions, and structure-dependence appears via physical form-factors and their derivatives. We apply our general method to study the leading finitesize structure-dependence in the pseudoscalar mass (at order 1/L3) as well as in the leptonic decay amplitudes of pions and kaons (at order 1/L2). Knowledge of the latter is essential for Standard Model precision tests in the flavour physics sector from lattice simulations.