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RESEARCH PRODUCT
A$_{FB}$ in the SMEFT: precision Z physics at the LHC
Víctor Bresó-plaMartín González-alonsoA. Falkowskisubject
QuarkNuclear and High Energy PhysicsParticle physicsp p: scatteringangular distribution: asymmetryPhysics beyond the Standard Modelmedia_common.quotation_subjectFOS: Physical sciencesQC770-79801 natural sciencesAsymmetryStandard ModelquarkZ0: productionHigh Energy Physics - Phenomenology (hep-ph)effective field theoryflat directionNuclear and particle physics. Atomic energy. Radioactivity0103 physical sciencesEffective field theory010306 general physicsmedia_commonPhysicsLarge Hadron Colliderelectroweak interaction010308 nuclear & particles physicsprecision measurementnew physicsElectroweak interactionHigh Energy Physics::PhenomenologyObservableCERN LEP StorEffective Field Theoriescorrection: vertexHigh Energy Physics - Phenomenologyp p --> lepton+ lepton-CERN LHC Coll[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]Beyond Standard ModelHigh Energy Physics::Experimentdescription
We study the forward-backward asymmetry $A_{FB}$ in $pp \to \ell^+\ell^-$ at the Z peak within the Standard Model Effective Field Theory (SMEFT). We find that this observable provides per mille level constraints on the vertex corrections of the Z boson to quarks,which close a flat direction in the electroweak precision SMEFT fit. Moreover, we show that current $A_{FB}$ data is precise enough so that its inclusion in the fit improves significantly LEP bounds even in simple New Physics setups. This demonstrates that the LHC can compete with and complement LEP when it comes to precision measurements of the Z boson properties
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2021-03-22 |