and 2 . 0 for √ m$_{B}$$_{s}$/m$_{B}$$_{d}$ ξ , respectively. These still correspond to confidence levels of greater than 10%, however, and are therefore consistent with the data. The error bands in Figs. 5 and 6 are fairly broad and hence the statistical uncertainty at the physical point is large, ∼ 4.1–7.6% for Φ$_{B}$$_{s}$ / Φ$_{B}$$_{d}$ and ∼ 4.7–6.3% for √ m$_{B}$$_{s}$/m$_{B}$$_{d}$ ξ . This is due to the large statistical errors in our data points, as well as the fact that our lightest mass is still quite heavy, which forces us to extrapolate over a large mass range. We summarize the results of our preferred chiral extrapolation in Tab. VII and discuss the estimation of our systematic errors in the following section. FIG. 5: Chiral extrapolation of Φ$_{B}$$_{s}$ / Φ$_{B}$$_{l}$ = √ m$_{B}$$_{s}$/m$_{B}$$_{l}$ · f$_{B}$$_{s}$/f$_{B}$$_{l}$ . The blue (triangle) points denote the APE data, while the red (square) points denote the HYP-smeared data. The color of the shaded (hatched) error band corresponds to those of the APE (HYP) data points. The dashed vertical line denotes the physical average u - d quark mass and the black dot denotes the physical strange quark mass, at which the SU (3)-breaking ratio must be one. The SU (2) HM χ PT coefficients obtained from the fit are R$_{Φ}$ = 1 . 21(9) and C$_{l}$ = 1 . 1(6) in the case of APE smearing and R$_{Φ}$ = 1 . 19(5) and C$_{l}$ = 1 . 2(3) in the case of HYP smearing. Errors shown are statistical only. 29 a ( m$_{l}$ + m$_{res}$ ) Φ B s / Φ B l APE: Φ$_{B}$$_{s}$ / Φ$_{B}$$_{d}$ = 1 . 165(88) , χ $^{2}$/ dof = 0 . 8 HYP: Φ$_{B}$$_{s}$ / Φ$_{B}$$_{d}$ = 1 . 153(47) , χ $^{2}$/ dof = 1 . 8