20 with Note that ϵ$_{1}$$_{,}$$_{2}$$_{,}$$_{3}$ are all proportional to X which contains a double suppression factor. This feature was the main ingredient for the compatibility of the D-BESS model with the EW precision tests. In the five dimensional formulation of this model the ratio ( g/ ¯ g$_{5}$ ) 2 originates from the presence of brane localized kinetic terms. The ϵ parameters can be tested against the experimental data. To do this, we need to express the model parameters in terms of the physical quantities. Proceeding again as in [60] we get the expressions the standard input parameters α , G$_{F}$ and m$_{Z}$ in terms of the model parameters. For convenience we rewrite the results: In section VI, we will study the constraints on the model parameter space by EW precision parameter for two choices of the warp factor, b ( y ) ≡ 1 (flat extra dimension) and b ( y ) = e − 2 ky (a slice of AdS$_{5}$). To this aim we need to invert (73), (74) and (75), then, using definitions (65), obtain also ˜ g and ˜ g ′ . X = m 2 Z ¯ M 2 ( g ¯ g$_{5}$ ) 2 . (72) with α ≡ e 2 4 π = g $^{2}$s2 θ 4 π , (73) m 2 Z = ˜ M 2 Z ( 1 − z$_{Z}$ ˜ M 2 Z ¯ M 2 ) , m 2 W = ˜ M 2 W ( 1 − z$_{W}$ ˜ M 2 W ¯ M 2 ) , (74) G$_{F}$ √$_{2}$ ≡ e 2 8 s 2 θ $_{0}$c 2 θ $_{0}$m 2 Z , s 2 θ $_{0}$c 2 θ 0 = s 2 $_{θ}$c 2 θ ( 1 + z$_{Z}$ m 2 Z ¯ M 2 ) , (75) z$_{Z}$ = g $^{2}$( c 4 θ + s 4 $_{θ}$) c 2 θ ¯ g 2 5 , ˜ M 2 Z = v $^{2}$( g 2 + g ′ $^{2}$) 4 (76) z$_{W}$ = g 2 ¯ g 2 5 , ˜ M 2 W = v $^{2}$g2 4 (77) g 2 = 4 πα s 2 θ 0 ( 1 + 4 πα ( c 4 θ 0 + s 4 θ $_{0}$) ¯ g 2 $_{5}$s 2 θ $_{0}$c$_{2}$$_{θ}$$_{0}$ m 2 Z ¯ M 2 ) , (78) g $^{′}$2 = 4 πα c 2 θ 0 1 − 4 πα ( c 4 θ 0 + s 4 θ $_{0}$) ¯ g 2 $_{5}$c 2 θ $_{0}$c$_{2}$$_{θ}$$_{0}$ m 2 Z ¯ M 2 , (79) v 2 = 4 g 2 + g ′ $_{2}$m 2 Z ( 1 + 4 πα ( c 4 θ 0 + s 4 θ $_{0}$) ¯ g 2 $_{5}$s 2 θ $_{0}$c 2 θ 0 m 2 Z ¯ M 2 ) = 1 √$_{2}$$_{G}$$_{F}$ ; (80)