We generalize the basis of CP-even chiral effective operators describing a dynamical Higgs sector, to the case in which the Higgs-like particle is light. Gauge and gauge-Higgs operators are considered up to four derivatives. This analysis completes the tool needed to explore at leading order the connection between linear realizations of the electroweak symmetry breaking mechanism -whose extreme case is the Standard Model -and non-linear realizations with a light Higgs-like particle present. It may also provide a model-independent guideline to explore which exotic gauge-Higgs couplings may be expected, and their relative strength to Higgsless observable amplitudes. With respect to fermions, the analysis is reduced by nature to the consideration of those flavour-conserving operators that can be written in terms of pure-gauge or gauge-Higgs ones via the equations of motion, but for the standard Yukawa-type couplings.

We determine the complete set of independent gauge and gauge-Higgs CPodd effective operators for the generic case of a dynamical Higgs, up to four derivatives in the chiral expansion. The relation with the linear basis of dimension six CP-odd operators is clarified. Phenomenological applications include bounds inferred from electric dipole moment limits, and from present and future collider data on triple gauge coupling measurements and Higgs signals.

CorrigendumCorrigendum to "The effective chiral Lagrangian for a light dynamical "Higgs Particle" " [Phys. Lett. B 722 (2013) It follows that the following two operators, can be reduced to a combination of P 6 (h) + P 18 (h) and P 21 (h) + P 23 (h), respectively, plus a term that can be absorbed in the redefinition of the couplings of the gauge bosons and h, plus a term containing a dependence on the Yukawa couplings. When fermion masses are considered, these operators are redundant; otherwise they are independent and must be taken into consideration.We profit from this erratum to point out another fact, although it has no impact on the basis. The equations of motion for the gauge fields and the Dirac equation in the section Massive fermions: As a result, the two structures containing the contractionThis change has not impact neither on the total number of operators of the basis nor on its composition. In particular, as stated in the article, operators P 11−13 (h) are physical only when fermion masses are considered, otherwise they can be written in terms of the other operators of the basis. The same applies to operators P 16 (h) and P 17 (h).An updated version of this article, with all the operators consecutively renumbered can be found in Ref. [1].

All the possible CP-conserving non-linear operators up to the p 4 -order in the Lagrangian expansion are clearly and completely listed for the case of an emerging new physics field content in the nature, more specifically, from spin-1 resonances sourced by the straightforward extension of the SM local gauge symmetry to the larger local group SU (2)L ⊗ SU (2)R ⊗ U (1)B−L, within a nonlinear electroweak chiral context coupled to a light dynamical Higgs. The physical effects induced by integrating out the right handed fields from the physical spectrum are briefly analysed. The relevant set of effective operators have been identified at low energies.

The Higgs-fermion couplings are sensitive probes of possible new physics behind a stable light Higgs particle. It is then essential to identify the flavor pattern of those interactions. We consider the case in which a strong dynamics lies behind a light Higgs and explore the implications within the minimal flavor violation ansatz. The dominant effects on flavor-changing Higgs-fermion couplings stem in this context from operators with mass dimension ≤5, and we analyze all relevant chiral operators up to that order, including loop corrections induced by four-dimensional ones. Bounds on the operator coefficients are derived from a plethora of low-energy flavor transitions, providing a guideline on which flavor-changing Higgs interactions may be open to experimental scrutiny. In particular, the coefficient of a genuinely CP-odd operator is only softly constrained and therefore its impact is potentially interesting