${{\mathit D}_{{{s}}}^{\pm}}{{\mathit \chi}^{2}}$ TESTS OF $\mathit CP$-VIOLATION ($\mathit CPV$)

We list model-independent searches for local $\mathit CP$ violation in phase-space distributions of multi-body decays.
Most of these searches divide phase space (Dalitz plot for 3-body decays, five-dimensional equivalent for 4-body decays) into bins, and perform a ${{\mathit \chi}^{2}}$ test comparing normalised yields ${{\mathit N}_{{{i}}}}$, ${{\overline{\mathit N}}_{{{i}}}}$ in $\mathit CP$-conjugate bin pairs ${{\mathit i}}$: ${{\mathit \chi}^{2}}$ = ${{\mathit \Sigma}_{{{i}}}}({{\mathit N}_{{{i}}}}$ $−$ ${{\mathit \alpha}}{{\overline{\mathit N}}_{{{i}}}})/{{\mathit \sigma}}({{\mathit N}_{{{i}}}}−{{\mathit \alpha}}{{\overline{\mathit N}}_{{{i}}}}$). The factor ${{\mathit \alpha}}$ = (${{\mathit \Sigma}_{{{i}}}}{{\mathit N}_{{{i}}}})/({{\mathit \Sigma}_{{{i}}}}{{\overline{\mathit N}}_{{{i}}}}$) removes the dependence on phase-space-integrated rate asymmetries. The result is used to obtain the probability (p-value) to obtain the measured ${{\mathit \chi}^{2}}$ or larger under the assumption of CP conservation [AUBERT 2008AO, BEDIAGA 2009]. Alternative methods obtain p-values from other test variables based on unbinned analyses [WILLIAMS 2011, AAIJ 2014C]. Results can be combined using Fisher's method [MOSTELLER 1948].

Local $\mathit CPV$ in ${{\mathit D}_{{{s}}}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit K}^{\pm}}$

INSPIRE   PDGID:
S034L01
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{0.133}$ 970k
AAIJ
2023L
 LHCB ${{\mathit \chi}^{2}}$
References