# VECTOR FORM FACTOR SLOPE PARAMETER $\boldsymbol a$ INSPIRE search

This is $\mathit a$ in $\mathit F_{V}$(q${}^{2}$) = $\mathit F_{V}$(0) (1 + $\mathit a$ q${}^{2}$)
VALUE EVTS DOCUMENT ID TECN  COMMENT
$0.10$ $\pm0.06$ 65k
 2009
PIBE ${{\mathit e}^{+}}{{\mathit \nu}}{{\mathit \gamma}}$ at rest
References:
 BYCHKOV 2009
PRL 103 051802 New Precise Measurement of the Pion Weak Form Factors in ${{\mathit \pi}^{+}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit \nu}}{{\mathit \gamma}}$ Decay