3 research outputs found
Bounds on the Masses and Couplings of Leptoquarks from Leptonic Partial Widths of the Z
The vertex corrections to the leptonic partial widths of the induced by
leptoquarks that couple leptons to the top quark are considered. We obtain
stringent bounds on the parameter space of the masses and Yukawa couplings of
these leptoquarks, using the latest information on the
decay widths measured at LEP. Leptoquarks coupling with electroweak strength to
top quarks are constrained to be heavier than several hundred GeV, at 95
C.L. As a consequence, such leptoquarks cannot make a significant contribution
to lepton asymmetries, polarisation asymmetries or .Comment: 11 pages + 3 Figures (available upon request), Latex file, CERN
preprint CERN-TH.7280/9
Bounds on second generation scalar leptoquarks from the anomalous magnetic moment of the muon
We calculate the contribution of second generation scalar leptoquarks to the
anomalous magnetic moment of the muon (AMMM). In the near future, E-821 at
Brookhaven will reduce the experimental error on this parameter to , an improvement of 20 over its current value.
With this new experimental limit we obtain a lower mass limit of
\ GeV for the second generation scalar leptoquark, when its
Yukawa-like coupling \ to quarks and leptons is taken to be
of the order of the electroweak coupling .Comment: 5 pages, plain tex, 1 figure (not included available under request