Global effective-field-theory analysis of new-physics effects in (semi)leptonic kaon decays

We analyze the decays k → πℓν and p → ℓν (p = k, π, ℓ = e, μ) using a low-energy effective-field-theory approach to parametrize new physics and study the complementarity with baryon β decays. we then provide a road map for a global analysis of the experimental data, with all the wilson coefficients simultaneously, and perform a fit leading to numerical bounds for them and for v us . a prominent result of our analysis is a reinterpretation of the well-known v ud − v us diagram as a strong constraint on new physics. finally, we reinterpret our bounds in terms of the su(2) l × u(1) y -invariant operators, provide bounds to the corresponding wilson coefficients at the tev scale and compare our results with collider searches at the lhc.