# $\boldsymbol g{}^{{{\boldsymbol Z}}}_{4}$ INSPIRE search

This coupling is $\mathit CP$-violating ($\mathit C$-violating and $\mathit P$-conserving).
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.30 \pm0.17}$ OUR AVERAGE
$-0.39$ ${}^{+0.19}_{-0.20}$ 1880 1
 2008 C
DLPH ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $189 - 209$ GeV
$-0.02$ ${}^{+0.32}_{-0.33}$ 1065 2
 2001 H
OPAL ${\it{}E}^{\it{}ee}_{\rm{}cm}$= 189 GeV
1  ABDALLAH 2008C determine this triple gauge coupling from the measurement of the spin density matrix elements in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ $\rightarrow$ ( ${{\mathit q}}{{\mathit q}}$) ( ${{\mathit \ell}}{{\mathit \nu}}$), where ${{\mathit \ell}}$ = ${{\mathit e}}$ or ${{\mathit \mu}}$. Values of all other couplings are fixed to their standard model values.
2  ABBIENDI 2001H study ${{\mathit W}}$-pair events, with one leptonically and one hadronically decaying ${{\mathit W}}$. The coupling is extracted using information from the ${{\mathit W}}$ production angle together with decay angles from the leptonically decaying ${{\mathit W}}$.
References:
 ABDALLAH 2008C
EPJ C54 345 Study of ${{\mathit W}}$ Boson Polarisations and Triple Gauge Boson Couplings in the Reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ at LEP 2
 ABBIENDI 2001H
EPJ C19 229 Measurement of ${{\mathit W}}$ Boson Polarizations and $\mathit CP$ Violating Triple Gauge Couplings from ${{\mathit W}^{+}}{{\mathit W}^{-}}$ Production at LEP