Abstract
We study the sensitivity of the Large Hadron Collider (LHC) to anomalous tbW couplings in single-top production in association with a W − boson followed by semilep-tonic decay of the top. We calculate top polarization and the effects of these anomalous couplings to it at two centre-of-mass (cm) energies of 7 TeV and 14 TeV. As a measure of top polarization, we look at various laboratory frame distributions of its decay products, viz., lepton angular and energy distributions and b-quark angular distributions, without requiring reconstruction of the rest frame of the top, and study the effect of anomalous couplings on these distributions. We construct certain asymmetries to study the sensitivity of these distributions to anomalous tbW couplings. The W t single-top production mode helps to isolate the anomalous tbW couplings in contrast to top-pair production and other single-top production modes, where other new-physics effects can also contribute. We find separate limits on real and imaginary parts of the dominant anomalous coupling f2R which may be obtained by utilizing these asymmetries at the LHC.
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Rindani, S.D., Sharma, P. Probing anomalous tbW couplings in single-top production using top polarization at the Large Hadron Collider. J. High Energ. Phys. 2011, 82 (2011). https://doi.org/10.1007/JHEP11(2011)082
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DOI: https://doi.org/10.1007/JHEP11(2011)082