Transverse beam polarization and limits on leptoquark couplings in e+e- --> t tbar

Abstract

It is shown that if electron and positron beams at a linear collider are transversely polarized, azimuthal asymmetries of the final-state top quark in e+e- --> t tbar can be used to probe a combination of couplings of left and right chiralities in a scalar leptoquark model. The CP-conserving azimuthal asymmetry would be a sensitive test of the chirality violating couplings. A linear collider operating at sqrt{s}=500 GeV and having transverse polarizations of 80% and 60% respectively for the e- and e+ beams, can put a limit of the order of 0.025 on the product of the left and right chirality leptoquark couplings (in units of the electromagnetic coupling constant), with a leptoquark mass of 1 TeV and for an integrated luminosity of 500 inverse fb. The CP-violating azimuthal asymmetry, which would provide a direct test of CP-violating phases in leptoquark couplings, can be constrained to the same level of accuracy. However, this limit is uninteresting in view of the much better indirect limit from the electric dipole moment of the electron.

13 pages latex, with 6 figures included. Revised version corrects minor error. Latest version corrects minor errors, to appear in Phys. Lett. B

References in corpus (7)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Transverse beam polarization and CP-violating triple-gauge-boson couplings in e+e- -> gamma Z
• Transverse Polarization Signatures of Extra Dimensions at Linear Colliders
• CP violation at a linear collider with transverse polarization
• CP sensitive observables in chargino production with transverse $e^{\pm }$ beam polarization
• Probing triple gauge couplings with transverse beam polarisation in e+e- -> W+W-
• More Transverse Polarization Signatures of Extra Dimensions at Linear Colliders

Cited by in corpus (13)

• Physics of leptoquarks in precision experiments and at particle colliders
• The role of polarized positrons and electrons in revealing fundamental interactions at the Linear Collider
• Angular distributions as a probe of anomalous ZZH and gammaZH interactions at a linear collider with polarized beams
• Use of transverse beam polarization to probe anomalous VVH interactions at a Linear Collider
• CP-odd observables in neutralino production with transverse e+ and e- beam polarization
• Transverse beam polarization and CP violation in e+ e- -> gamma Z with contact interactions
• Probing CP-violating contact interactions in e+e- --> HZ with polarized beams
• Disentangling the Unparticles with polarized beams at e+e- colliders
• Selectron production at an e-e- linear collider with transversely polarized beams
• Charged lepton distributions as a probe of contact e+e-HZ interactions at a linear collider with polarized beams
• Two-particle kinematic distributions from new physics at an electron-positron collider with polarized beams
• Use of Transverse polarization to probe R-parity violating supersymmetry at ILC
• Distinguishing nonstandard scalar and fermionic charged particles at future $e^{+}{e}^{-}$ collider