| Abstract |
content_type = "text/plain"
user_agent = "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)"
moz = "Mozilla/5.0 "
moz_version = "5"
We perform a time-dependent amplitude analysis of $B^0 \to K^0_S\pi^+\pi^-$ decays to extract
the CP violation parameters of $f_0(980) K^0_S$ and $\rho^0(770) K^0_S$ and the direct CP asymmetry
of $K^{*+}(892) \pi^-$.
The results are obtained from a data sample of $(383 \pm 3) \times 10^6$ $B\bar{B}$ decays, collected
with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at SLAC.
We find two solutions, with an equivalent goodness-of-fit. Including systematic and Dalitz plot model
uncertainties, the combined confidence interval for values of the CP parameter $\beta_{eff}$ in
$B^0$ decays to $f_0(980) K^0_S$ is $18^o < \beta_{eff} < 76^o$ at $95\%$ confidence level (C.L).
CP conservation in $B^0$ decays to $f_0(980) K^0_S$ is excluded at $3.5\sigma$
including systematic uncertainties. For $B^0$ decays to $\rho^0(770) K^0_S$,
the combined confidence interval is $-9^o < \beta_{eff} < 57^o$ at $95\%$ C.L. In decays to
$K^{*+}(892) \pi^-$ we measure the direct CP asymmetry to be $A_{CP}=-0.20 \pm 0.10 \pm 0.01 \pm 0.02$.
The measured phase difference (including $B^0\bar{B}^0$ mixing) between decay amplitudes of
$B^0 \to K^{*+}(892) \pi^-$ and $\bar{B}^0 \to K^{*-}(892) \pi^+$,
excludes the interval $-137^o < \Delta\Phi(K^{*+}(892) \pi^-) < -5^o$ at $95\%$ C.L.
|
