First model-independent Dalitz analysis of $B^0 \to D^0K^{\ast 0}$, $D\to K_S^0\pi ^+\pi ^-$ decayNegishi, K. (Avtor) Biswal, Jyoti Prakash (Avtor) Bračko, Marko (Avtor) Golob, Boštjan (Avtor) Korpar, Samo (Avtor) Križan, Peter (Avtor) Nanut, Tara (Avtor) Pestotnik, Rok (Avtor) Petrič, Marko (Avtor) Ribežl, Eva (Avtor) Stanič, Samo (Avtor) Starič, Marko (Avtor) Šantelj, Luka (Avtor) Zupanc, Anže (Avtor) CO2CO3Cabibbo-Kobayashi-Maskawa quark-mixing matrixCP violationexperimental particle physicsWe report a measurement of the amplitude ratio $r_S$ of $B^0 \to D^0K^{\ast 0}$ and $B^0 \to \bar {D^0}K^{\ast 0}$ decays with a Dalitz analysis of $D\to K_S^0\pi ^+\pi ^-$ decays, for the first time using a model-independent method. We set an upper limit $r_S < 0.87$ at the 68% confidence level, using the full data sample of $711\,{\rm fb}^{-1}$ corresponding to $772\times 10^6$ $B\bar {B}$ pairs collected at the $\Upsilon (4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. This result is obtained from observables $x_- = +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} \pm 0.0$, $y_- = -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} \pm 0.1$, $x_+ = +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} \pm 0.1$, and $y_+ = +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} \pm 0.1$, where $x_\pm = r_S \cos (\delta _S \pm \phi _3)$, $y_\pm = r_S \sin (\delta _S \pm \phi _3)$, and $\phi _3\ (\delta _S)$ is the weak (strong) phase difference between $B^0 \to D^0K^{\ast 0}$ and $B^0 \to \bar {D^0}K^{\ast 0}$.20162017-07-21 10:51:43Znanstveno delo66970ISSN: 2050-3911UDK: 539.1OceCobissID: 2704635COBISS_ID: 29823527DOI: 10.1093/ptep/ptw030ISSN pri članku: 2050-3911NUK URN: URN:SI:UM:DK:HTVDLRHMsl