Higgs decay to fermion pairs at NLO in SMEFT

Abstract

The calculation of next-to-leading order (NLO) perturbative corrections at fixed operator dimension in Standard Model Effective Field Theory (SMEFT) has been a topic of much recent interest. In this paper we obtain the NLO corrections from dimension-6 operators to the Higgs boson decays $$ h\to f\overline{f} $$ h → f f ¯ , where the fermions f ∈ {μ, τ, c}. This extends previous results for $$ h\to b\overline{b} $$ h → b b ¯ to all phenomenologically relevant Higgs boson decays into fermions, and provides the basis for future precision analyses of these decays within effective field theory. We point out the benefits of studying ratios of decay rates into different fermions in SMEFT, the most surprising of which is enhanced sensitivity to anomalous hγγ and hgg couplings induced by flavor-universal SMEFT operators, especially in scenarios where flavor-dependent Wilson coefficients are constrained by Minimal Flavor Violation.

One loop verification of SMEFT Ward Identities

“…[39], and this point is also consistent with discussion in Ref. [40,41], which recognizes this modification of Ward identities is present.…”

“…In the literature, one loop calculations have been done in the SMEFT within the BFM [15,22,35,[42][43][44][45][46], and also outside of the BFM [23,40,41,[47][48][49][50][51][52][53]. It is important, when comparing results, that one recognizes that radiative scheme dependence, includes differing dependence on Wilson coefficients in the two point functions.…”

Flavorful Electroweak Precision Observables in the Standard Model Effective Field Theory

“…These bounds rely on precision calculations of the theoretical expectations both in the Standard Model (SM) and in the SMEFT. SMEFT calculations at next-to-leading order (NLO) QCD can be automated [7], while a growing number of SMEFT electroweak NLO results exist [1,[8][9][10][11][12][13][14][15][16][17][18][19][20]. In a previous work [1], we computed the O( M 2 Z Λ 2 ) NLO QCD and electroweak corrections to the SMEFT predictions for EWPO at the Z and W poles.…”

SMEFT calculations for the LHC

“…F R implementations in R ξ gauge have been made available [63][64][65], which partially simplifies the task of computing Feynman diagrams. Full NLO EW calculations in the SMEFT have been completed for µ → eγ [66], 2-body Higgs decays [67][68][69][70][71][72][73][74][75][76], Z, W pole observables [77][78][79] and Drell-Yan [80].…”