Parametrizes $\mathit CP$ violation in the interference between ${{\mathit D}^{0}}$ mixing and decay. The mass eigenstates ${{\mathit D}_{{1}}^{0}}$ and ${{\mathit D}_{{2}}^{0}}$ are related to the $\mathit C$ = $\pm1$ states by $|{{\mathit D}_{{1,2}}}>$ = p$~|{{\mathit D}^{0}}>$ + q $|{{\overline{\mathit D}}^{0}}>$. In the absence of $\mathit CP$ violation in the decay, and using the usual phase convention where $\mathit CP$ conservation implies q/p is real, $\phi {}^{ {{\mathit K}_S^0} {{\mathit \pi}} {{\mathit \pi}} }$ is identical to the decay-mode-independent parameter $\phi $ = arg(q/p).

VALUE EVTS DOCUMENT ID TECN  COMMENT $\bf{ 0.02 {}^{+0.04}_{-0.05}}$ OUR AVERAGE $0.056$ ${}^{+0.047}_{-0.051}$ 30.6M 1 AAIJ 2021 AB LHCB ${{\mathit p}}{{\mathit p}}$ at 13 TeV $-0.09$ ${}^{+0.11}_{-0.16}$ 2.3M 2 AAIJ 2019 X LHCB ${{\mathit p}}{{\mathit p}}$ at 7, 8 TeV $-0.10$ $\pm0.19$ ${}^{+0.07}_{-0.09}$ 1.2M 3 PENG 2014 BELL ${{\mathit e}^{+}}{{\mathit e}^{-}}$ at ${{\mathit \Upsilon}{(4S,5S)}}$ 1  AAIJ 2021AB result comes form analysis of ${{\mathit D}^{0}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ events. 2  AAIJ 2019X result comes form analysis of ${{\mathit D}^{0}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ events. ${{\mathit D}^{0}}$ come from ${{\mathit D}^{*+}}$ and ${{\overline{\mathit B}}}$ $\rightarrow$ ${{\mathit D}^{0}}{{\mathit \mu}^{-}}{{\mathit X}}$ decays (and c.c.) in ${{\mathit p}}{{\mathit p}}$ collisions at 7 and 8 TeV. 3  PENG 2014 reports $-0.10$ $\pm0.19$ $\pm0.05$ ${}^{+0.05}_{-0.07}$ value where the last uncertainty is due to the amplitude model. We have added the systematic uncertainties in quadrature.

References:

AAIJ 2021AB PRL 127 111801 Observation of the Mass Difference Between Neutral Charm-Meson Eigenstates AAIJ 2019X PRL 122 231802 Measurement of the mass difference between neutral charm-meson eigenstates PENG 2014 PR D89 091103 Measurement of ${{\mathit D}^{0}}−{{\overline{\mathit D}}^{0}}$ Mixing and Search for Indirect $\mathit CP$ Violation using ${{\mathit D}^{0}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ Decays