Higgs boson signal at complete tree level in the SM extension by dimension-six operators

Deviations from the standard Higgs sector generated by some new (nonstandard) physics at an energy scale. could be described by effective SU(3)(c) x SU(2)(L) x U(1) invariant nonrenormalizable Lagrangian terms of dimension six. The set of dimension-six operators involving the Higgs field is chosen in such a way that the form of the gauge boson kinetic terms remains untouched, preserving all high-precision electroweak constraints. A systematic study of effects in various Higgs boson production channels (gamma gamma, ZZ, WW, b (b) over bar, tau(tau) over bar) caused by effective operators is carried out beyond the production x decay approximation (or infinitely small width approximation). Statistical methods are used to establish the consistency of the standard Higgs sector with the available LHC data. A global fit in the two-parametric anomalous coupling space indicating possible deviations from the standard Higgs-fermion and Higgs-gauge boson couplings is performed, using post-Moriond 2012 data and more precise LC2013 data. We find that the standard Higgs sector is consistent with the current CMS and ATLAS experimental results both in the infinitely small width approximation and the calculation with complete gauge-invariant sets of diagrams. However, a visible difference between the exclusion contours is found for some combinations of production and decay channels, although it is minor for the global fits for all possible channels. Updates of the signal strength and the signal strength error reported at LC2013 result in significant improvements of the allowed regions in the anomalous coupling space, which are also recalculated at complete tree level.