KTeV Kl3 form factor plots
Updated Nov. 7, 2010.
[Kl3 form factor Results]
Plots from
[PRD 70, 092007 (2004)],
[PRD 74, 097101 (2006)],
PRD 81, 052001 (2010)
"Dispersive analysis of Kl3 form factors"

CTKTeVlatbf.eps,
CTKTeVlatbf.pdf
Fig.1: The constraints on f+(0) and FK/Fpi from various lattice QCD calculations. The KTeV result for FK /(Fpi f+(0)) is shown as the red solid line, derived by using the Callan Treiman relation and the NLO result for DeltaCT. Also shown is the error due to DeltaCT (red dotted lines), and the resulting error when added in quadrature to the total error on C as given in Eq. (8) (red dotdashed line).


CTKTeVSMN.eps,
CTKTeVSMN.pdf
Fig.2: The constraints on f+ (0) and FK /Fpi. The inserted Chi2 − Chi2MIN = 1 ellipse is the SM result obtained from Eqs. (15) and (16) and the CKM unitarity. The dashed green line and its error bar (green dotted line) corresponds to FK /(Fpi f+(0))SM, calculated using the measured decay widths and assuming the SM couplings of light quarks, Eq. (20). Shown in red is the FK /(Fpi f+(0)) result, derived from the dispersive parameterization fit to KTeV data and the NLO result for DeltaCT. Also shown is the error due to DeltaCT (red dotted lines) added in quadrature to the total error on C as given in Eq. (8) (red dotdashed line).


lambvktevf1.eps,
lambvktevf1.pdf
Fig.3: Dependence of the fitted values of ln C and Lambda'+ on the curvature, Lambda''+. The value of ln C and the Chi2 of the corresponding fit are given in parenthesis above each point. To simulate the presence of higher order terms in the zparameterization, for the red line a third order term has been included. The effect of this third order term is only to shift the curve downwards. In the legend, ”quad./disp.” for example indicates that a "quadratic" parametrization is used for the vector form factor and a "dispersive" one for the scalar.

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