No Arabic abstract
We report a measurement of the amplitude ratio $r_S$ of $B^0 to D^0K^{*0}$ and $B^0 to bar{D^0}K^{*0}$ decays with a Dalitz analysis of $Dto K_S^0pi^+pi^-$ 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 $772times10^6$ $Bbar{B}$ pairs collected at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. This result is obtained from observables $x_- = +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} pm0.0$, $y_- = -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} pm0.1$, $x_+ = +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} pm0.1$ and $y_+ = +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} pm0.1$, 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 $B^0 to D^0K^{*0}$ and $B^0 to bar{D^0}K^{*0}$.
We report a measurement of the amplitude ratio $r_S$ of $B^0 to D^0K^{*0}$ and $B^0 to bar{D^0}K^{*0}$ decays with a model-independent Dalitz plot analysis using $Dto K_S^0pi^+pi^-$ decays. Using the full data sample of $772times10^6$ $Bbar{B}$ pairs collected at the $Upsilon(4S)$ resonance with the Belle detector at KEKB accelerator the upper limit is $r_S < 0.87$ at the 68 % confidence level. This result is the first measurement of $r_S$ with a model-independent Dalitz analysis, and is consistent with results from other analyses. The value of $r_S$ indicates the sensitivity of the decay to $phi_3$ because the statistical uncertainty is proportional to $1/r_S$. The $r_S$ result is obtained from observables ($x_pm$, $y_pm$) begin{eqnarray} x_- &=& +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} pm0.0 y_- &=& -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} pm0.1 x_+ &=& +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} pm0.1 y_+ &=& +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} pm0.1 , end{eqnarray} where $x_pm = r_S cos(delta_S pm phi_3)$, $y_pm = r_S sin(delta_S pm phi_3)$ and $phi_3 (delta_S)$ are the weak (strong) phase difference between $B^0 to D^0K^{*0}$ and $B^0 to bar{D^0}K^{*0}$. The first uncertainty is statistical, the second is the experimental systematic and the third is the systematic due to the uncertainties on $c_i$ and $s_i$ parameters measured by CLEO.
Using 9.0/fb of integrated luminosity in e+e- collisions near Upsilon(4S) mass collected with the CLEO II.V detector we report the first observation of the decay D0 -> K0S ETA PI0 We measure the ratio of branching fractions, BR(D0 -> K0S ETA PI0) / BR(D0 -> K0S PI0) = 0.46 +- 0.07 +- 0.06. We perform a Dalitz analysis of 155 selected D0 -> K0S ETA PI0 candidates and find leading contributions from a_0(980) K0S and K*(892) ETA intermediate states.
The resonant substructures of $B^0 to overline{D}^0 pi^+pi^-$ decays are studied with the Dalitz plot technique. In this study a data sample corresponding to an integrated luminosity of 3.0 fb$^{-1}$ of $pp$ collisions collected by the LHCb detector is used. The branching fraction of the $B^0 to overline{D}^0 pi^+pi^-$ decay in the region $m(overline{D}^0pi^{pm})>2.1$ GeV$/c^2$ is measured to be $(8.46 pm 0.14 pm 0.29 pm 0.40) times 10^{-4}$, where the first uncertainty is statistical, the second is systematic and the last arises from the normalisation channel $B^0 to D^*(2010)^-pi^+$. The $pi^+pi^-$ S-wave components are modelled with the Isobar and K-matrix formalisms. Results of the Dalitz plot analyses using both models are presented. A resonant structure at $m(overline{D}^0pi^-) approx 2.8$ GeV$/c^{2}$ is confirmed and its spin-parity is determined for the first time as $J^P = 3^-$. The branching fraction, mass and width of this structure are determined together with those of the $D^*_0(2400)^-$ and $D^*_2(2460)^-$ resonances. The branching fractions of other $B^0 to overline{D}^0 h^0$ decay components with $h^0 to pi^+pi^-$ are also reported. Many of these branching fraction measurements are the most precise to date. The first observation of the decays $B^0 to overline{D}^0 f_0(500)$, $B^0 to overline{D}^0 f_0(980)$, $B^0 to overline{D}^0 rho(1450)$, $B^0 to D_3^*(2760)^- pi^+$ and the first evidence of $B^0 to overline{D}^0 f_0(2020)$ are presented.
We present a measurement of $B(pi^0 rightarrow e^+e^- gamma)/B(pi^0 rightarrow gammagamma)$, the Dalitz branching ratio, using data taken in 1999 by the E832 KTeV experiment at Fermi National Accelerator Laboratory. We use neutral pions from fully reconstructed $K_L$ decays in flight; the measurement is based on about 60 thousand $K_L rightarrow pi^0pi^0pi^0 rightarrow gammagamma~gammagamma~e^+e^-gamma$ decays. We normalize to $K_L rightarrow pi^0pi^0pi^0 rightarrow 6gamma$ decays. We find $B(pi^0 rightarrow e^+e^- gamma)/B(pi^0 rightarrow gammagamma)$ $(m_{e^+e^-}$ > 15 MeV/$c^2)$ = $[3.920 pm 0.016(stat) pm 0.036 (syst)] times 10^{-3}$. Using the Mikaelian and Smith prediction for the $e^+e^-$ mass spectrum, we correct the result to the full $e^+e^-$ mass range. The corrected result is $B(pi^0 rightarrow e^+e^- gamma)/B(pi^0 rightarrow gammagamma) = [1.1559 pm 0.0047(stat) pm 0.0106 (syst)]$%. This result is consistent with previous measurements and the uncertainty is a factor of three smaller than any previous measurement.
We present the first measurement of the angle phi_3 of the Unitarity Triangle using a model-independent Dalitz plot analysis of B->DK, D->KsPiPi decays. The method uses an input measurements of the strong phase of the D->KsPiPi amplitude from the CLEO collaboration. The result is based on the full data set of 772x10^6 BBbar pairs collected by the Belle experiment at the Upsilon(4S) resonance. We obtain phi_3 = (77.3^{+15.1}_{-14.9} +- 4.1 +- 4.3)^{circ} and the suppressed amplitude ratio r_B = 0.145 +- 0.030 +- 0.010 +- 0.011. Here the first error is statistical, the second is the experimental systematic uncertainty, and the third is the error due to the precision of the strong-phase parameters obtained by CLEO.