6533b821fe1ef96bd127c216
RESEARCH PRODUCT
Constraints from lepton universality at the z-peak on unified theories
J. BernabéuApostolos Pilaftsissubject
PhysicsNuclear and High Energy PhysicsParticle physicsPartial widthmedia_common.quotation_subjectHigh Energy Physics::PhenomenologySymmetric modelFOS: Physical sciencesFísicaObservableParameter spacePolarization (waves)AsymmetryUniversality (dynamical systems)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics::ExperimentLeptonmedia_commondescription
We suggest the use of a universality-breaking observable based on lepton asymmetries as derived from the left-right asymmetry and the $\tau$ polarization at the $Z$ peak, which can efficiently constrain the parameter space of unified theories. The new observable is complementary to the leptonic partial width differences and it depends critically on the chirality of a possible non-universal $Z$-boson coupling to like-flavour leptons. The LEP/SLC potential of probing universality violation is discussed in representative low-energy extensions of the Standard Model (SM) that could be derived by supersymmetric grand unified theories, such as the SM with left-handed and/or right-handed neutral isosinglets, the left-right symmetric model, and the minimal supersymmetric SM.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1995-02-14 |