Journal of High Energy Physics

, 2012:11

Top polarisation studies in Ht and W t production

  • R. M. Godbole
  • L. Hartgring
  • I. Niessen
  • C. D. White
Open Access

DOI: 10.1007/JHEP01(2012)011

Cite this article as:
Godbole, R.M., Hartgring, L., Niessen, I. et al. J. High Energ. Phys. (2012) 2012: 11. doi:10.1007/JHEP01(2012)011


The polarisation of top quarks produced in high energy processes can be a very sensitive probe of physics beyond the Standard Model. The kinematical distributions of the decay products of the top quark can provide clean information on the polarisation of the produced top and thus can probe new physics effects in the top quark sector. We study some of the recently proposed polarisation observables involving the decay products of the top quark in the context of Ht and W t production. We show that the effect of the top polarisation on the decay lepton azimuthal angle distribution, studied recently for these processes at leading order in QCD, is robust with respect to the inclusion of next-to-leading order and parton shower corrections. We also consider the leptonic polar angle, as well as recently proposed energy-related distributions of the top decay products. We construct asymmetry parameters from these observables, which can be used to distinguish the new physics signal from the W t background and discriminate between different values of tan β and mH − in a general type II two-Higgs doublet model. Finally, we show that similar observables may be useful in separating a Standard Model W t signal from the much larger QCD induced top pair production background.


Higgs Physics Beyond Standard Model Standard Model 
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Copyright information

© SISSA, Trieste, Italy 2012

Authors and Affiliations

  • R. M. Godbole
    • 1
  • L. Hartgring
    • 2
  • I. Niessen
    • 3
  • C. D. White
    • 4
  1. 1.Center for High Energy Physics, Indian Institute of ScienceBangaloreIndia
  2. 2.NikhefAmsterdamThe Netherlands
  3. 3.Theoretical High Energy Physics, IMAPP, Faculty of ScienceNijmegenThe Netherlands
  4. 4.School of Physics and Astronomy, Scottish Universities Physics AllianceUniversity of GlasgowGlasgowU.K.

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