One-loop analysis of $\beta$ decays in SMEFT

• DOI: 10.48550/arxiv.2402.06723
• Publication Date: 2024-02-09
• Authors: Maria Dawid; Vincenzo Cirigliano; Wouter Dekens
• Keywords: BETA (programming language)

We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by high precision reached in experiment calculations for CC decays mesons, neutron, nuclei, lingering tension Cabibbo universality test. identify SMEFT operators that induce largest contributions to processes. These include four-quark four-fermion semileptonic two third-generation quarks. discuss available constraints on relevant effective couplings along way we derive new bounds from $K \to \pi \nu \bar \nu$ top find low-energy are quite competitive with other probes, set do not depend flavor-symmetry assumptions, probe up scales $\Lambda\simeq 8$ TeV. Finally, briefly single-field ultraviolet completions could operators.