Probing dimension-8 SMEFT operators through neutral meson mixing
Year: 2025
Type: article
Abstract: A bstract We investigate the impact of effective interactions of dimension-8 (dim-8) operators in the standard model effective field theory (SMEFT) on neutral meson mixing, focusing on the $$ {K}^0-{\overline{K}}^0 $$ K 0 − K ¯ 0 , $$ {B}_{d,s}-{\overline{B}}_{d,s} $$ B d , s − B ¯ d , s , and $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 systems. Within the framework of the low energy effective field theory (LEFT), each system is governed by eight dim-6 operators, with four originating at tree level from dim-6 SMEFT operators and the other four from dim-8 SMEFT operators. Notably, in certain UV complete models those dim-8 operators instead of the dim-6 ones are generated at the leading order. Our analysis focuses on those dim-8 operators and includes their one-loop QCD renormalization group running effects. By leveraging the LEFT master formula we impose stringent constraints on the effective scales associated with these dim-8 operators. We find that neutral meson mixing can probe an effective scale up to 80 TeV for some operators, surpassing the constraints imposed on other dim-8 operators by other observables. Lastly, we present a UV complete model capable of generating dim-8 operators at the leading order, thus offering a unique perspective on the interplay between different operator dimensions in probing new physics phenomena.
Source: Journal of High Energy Physics
Authors: Yi Liao, Xiao-Dong Ma, Hao-Lin Wang
Institution: South China Normal University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4408569665