https://doi.org/10.1140/epjc/s10052-011-1681-7
Regular Article - Theoretical Physics
Model-independent analysis of Higgs spin and CP properties in the process 
1
Theory Division, CERN TH-PH, 1211, Geneva 23, Switzerland
2
Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD, Utrecht, The Netherlands
3
Institut für Theoretische Physik, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
4
Theoretical Physics Division, Physical Research Laboratory, Navrangpura, Ahmedabad, 380 009, India
* e-mail: maggie@particle.uni-karlsruhe.de
Received:
19
April
2011
Revised:
25
May
2011
Published online:
29
June
2011
In this paper we investigate methods to study the 
Higgs coupling. The spin and CP properties of a Higgs boson are analysed in a model-independent way in its associated production with a pair in high-energy e
+
e
− collisions. We study the prospects of establishing the CP quantum numbers of the Higgs boson in the CP-conserving case as well as those of determining the CP-mixing if CP is violated. We explore in this analysis the combined use of the total cross section and its energy dependence, the polarisation asymmetry of the top quark and the up-down asymmetry of the antitop with respect to the top–electron plane. We find that combining all three observables remarkably reduces the error on the determination of the CP properties of the Higgs Yukawa coupling. Furthermore, the top polarisation asymmetry and the ratio of cross sections at different collider energies are shown to be sensitive to the spin of the particle produced in association with the top-quark pair.
© Springer-Verlag / Società Italiana di Fisica, 2011
