6533b7dafe1ef96bd126e0d9

RESEARCH PRODUCT

Gamma(Z --> bb): A signature of hard mass terms for a heavy top

Antonio PichArcadi SantamariaJose Bernabeu

subject

CouplingPhysicsNuclear and High Energy PhysicsGauge bosonParticle physicsNeutral currentHigh Energy Physics::LatticeHigh Energy Physics::PhenomenologyFísicaFermionlcsh:QC1-999Vertex (geometry)AmplitudeQuantum electrodynamicsRadiative transferHiggs bosonlcsh:Physics

description

Abstract We calculate analytically the weak radiative corrections to the weak neutral current gauge boson-bottom fermion vertex, keeping the mass mt of the internal fermion line for the relevant diagrams. We find, to order α, a hard mass-term dependence m t 2 M W 2 of the amplitude, for large mt values. Its origin comes from the unphysical charged Higgs coupling to fermions in the renormalizable gauge or, equivalently, from the longitudinal charged gauge boson couplings. The diagonal Z0 decay width to b-quarks decreases, due to these weak radiative corrections, by 0.6%–2.5% when the top mass mt varies from 45 to 200 GeV.

10.1016/0370-2693(88)90173-6http://dx.doi.org/10.1016/0370-2693(88)90173-6