${{\mathit K}_{{{{\mathit \ell}}4}}^{\pm}}$ FORM FACTORS

Based on the parametrizations of AMOROS 1999 , the ${{\mathit K}_{{{{\mathit \ell}}4}}^{\pm}}$ form factors can be expressed as
 $\mathit F_{s}$ = $\mathit f_{s}$ + ${{\mathit f}_{{s}}^{\,'}}$ q${}^{2}$ + ${{\mathit f}_{{s}}^{''}}$ q${}^{4}$ + ${{\mathit f}_{{e}}^{\,'}}$ S$_{e}$ $/$ 4${{\mathit m}^{2}}_{{{\mathit \pi}}}$
 $\mathit F_{p}$ = $\mathit f_{p}$
 $\mathit G_{p}$ = $\mathit g_{p}$ + ${{\mathit g}_{{p}}^{\,'}}$ q${}^{2}$
 $\mathit H_{p}$ = $\mathit h_{p}$
where q${}^{2}$ = (S$_{{{\mathit \pi}}}$ $/$ 4${{\mathit m}^{2}}_{{{\mathit \pi}}}$) $−$ 1, S$_{{{\mathit \pi}}}$ is the invariant mass squared of the dipion, and S$_{e}$ is the invariant mass squared of the dilepton.

DECAY FORM FACTOR FOR ${{\mathit K}^{\pm}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit e}^{\pm}}{{\mathit \nu}}$

INSPIRE   PDGID:
S010KF4
Given in BOLOTOV 1986B, BARMIN 1988B, and SHIMIZU 2004 .
VALUE