Renormalization group improved implications of semileptonic operators in SMEFT
Abstract
We study implications of the fourfermion semileptonic operators at the lowenergy and at electroweak (EW) scale in the framework of Standard Model Effective Field Theory (SMEFT). We show how the renormalization group (RG) running effects can play an important role in probing the \emph{generic flavour structure} of such operators. It is shown that at the 1loop level, through RG running, depending upon the flavour structure, these operators can give rise to sizable effects at low energy in the electroweak precision (EWP) observables, the leptonic, quark, as well as the $Z$ boson flavour violating decays. To this end, we isolate the phenomenological relevant terms in the full anomalous dimension matrices (ADMs) and discuss the impact of the QED+QCD running in the Weak effective field theory (WET) and the SMEFT running due to gauge and Yukawa interactions on the dim4 and dim6 operators at the low energy. Considering all the relevant processes, we derive lower bounds on the new physics (NP) scale $\Lambda$ for each semileptonic operator, keeping a generic flavour structure. In addition, we also report the allowed ranges for the Wilson coefficients at a fixed value of $\Lambda=3$ TeV.
 Publication:

arXiv eprints
 Pub Date:
 July 2021
 arXiv:
 arXiv:2107.13005
 Bibcode:
 2021arXiv210713005K
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment
 EPrint:
 37 pp, 9 figures, v2: Refs. added, typos corrected