اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدFirst evidence for $cos 2beta>0$ and resolution of the CKM Unitarity Triangle ambiguity by a time-dependent Dalitz plot analysis of $B^{0} to D^{(*)} h^{0}$ with $D to K_{S}^{0} pi^{+} pi^{-}$ decays
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We present first evidence that the cosine of the CP-violating weak phase $2beta$ is positive, and hence exclude trigonometric multifold solutions of the CKM Unitarity Triangle using a time-dependent Dalitz plot analysis of $B^{0} to D^{(*)} h^{0}$ with $D to K_{S}^{0} pi^{+} pi^{-}$ decays, where $h^{0} in {pi^{0}, eta, omega }$ denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BaBar and Belle experiments collected at the $Upsilon(4S)$ resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain $( 471 pm 3 )times 10^6, Bbar{B}$ pairs recorded by the BaBar detector and $( 772 pm 11 )times 10^6, Bbar{B}$ pairs recorded by the Belle detector. The results of the measurement are $sin{2beta} = 0.80 pm 0.14 ,(rm{stat.}) pm 0.06 ,(rm{syst.}) pm 0.03 ,(rm{model})$ and $cos{2beta} = 0.91 pm 0.22 ,(rm{stat.}) pm 0.09 ,(rm{syst.}) pm 0.07 ,(rm{model})$. The result for the direct measurement of the angle $beta$ of the CKM Unitarity Triangle is $beta = left( 22.5 pm 4.4 ,(rm{stat.}) pm 1.2 ,(rm{syst.}) pm 0.6 ,(rm{model}) right)^{circ}$. The quoted model uncertainties are due to the composition of the $D^{0} to K_{S}^{0} pi^{+} pi^{-}$ decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics $e^{+}e^{-} to cbar{c}$ data sample. CP violation is observed in $B^{0} to D^{(*)} h^{0}$ decays at the level of $5.1$ standard deviations. The significance for $cos{2beta}>0$ is $3.7$ standard deviations. The trigonometric multifold solution $pi/2 - beta = (68.1 pm 0.7)^{circ}$ is excluded at the level of $7.3$ standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.
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We report measurements of $sin{2beta}$ and $cos{2beta}$ from a time-dependent Dalitz plot analysis of $B^{0} to D^{(*)} h^{0}$ with $D to K_{S}^{0} pi^{+} pi^{-}$ decays, where the light unflavored and neutral hadron $h^{0}$ is a $pi^{0}$, $eta$, or
$omega$ meson. The analysis is performed with a combination of the final data sets of the babar and Belle experiments containing $471 times 10^{6}$ and $772 times 10^{6}$ $Bbar{B}$ pairs collected at the $Upsilonleft(4Sright)$ resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure $sin{2beta} = 0.80 pm 0.14 ,(rm{stat.}) pm 0.06 ,(rm{syst.}) pm 0.03 ,(rm{model})$ and $cos{2beta} = 0.91 pm 0.22 ,(rm{stat.}) pm 0.09 ,(rm{syst.}) pm 0.07 ,(rm{model})$. The result for the direct measurement of the angle is $beta = left( 22.5 pm 4.4 ,(rm{stat.}) pm 1.2 ,(rm{syst.}) pm 0.6 ,(rm{model}) right)^{circ}$. The last quoted uncertainties are due to the composition of the $D^{0} to K_{S}^{0} pi^{+} pi^{-}$ decay amplitude model, which is newly established by a Dalitz plot amplitude analysis of a high-statistics $e^{+}e^{-} to cbar{c}$ data sample as part of this analysis. We find the first evidence for $cos2beta>0$ at the level of $3.7$ standard deviations. The measurement excludes the trigonometric multifold solution $pi/2 - beta = (68.1 pm 0.7)^{circ}$ at the level of $7.3$ standard deviations and therefore resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. The hypothesis of $beta = 0^{circ}$ is ruled out at the level of $5.1$ standard deviations, and thus CP violation is observed in $B^{0} to D^{(*)} h^{0}$ decays.
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.
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The first study is presented of CP violation with an amplitude analysis of the Dalitz plot of $B^0 to D K^+ pi^-$ decays, with $D to K^+ pi^-$, $K^+ K^-$ and $pi^+ pi^-$. The analysis is based on a data sample corresponding to $3.0,{rm fb}^{-1}$ of $
pp$ collisions collected with the LHCb detector. No significant CP violation effect is seen, and constraints are placed on the angle $gamma$ of the unitarity triangle formed from elements of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Hadronic parameters associated with the $B^0 to D K^*(892)^0$ decay are determined for the first time. These measurements can be used to improve the sensitivity to $gamma$ of existing and future studies of the $B^0 to D K^*(892)^0$ decay.
We report a measurement of the CP violation parameter $varphi_1$ obtained in a time-dependent analysis of $B^0tobar{D}{}^{(*)0}h^0$ decays followed by $bar{D}{}^0to K_S^0pi^+pi^-$ decay. A model-independent measurement is performed using the binned D
alitz plot technique. The measured value is $varphi_1 = 11.7^{circ}pm7.8^{circ}({rm stat.})pm 2.1^{circ}({rm syst.})$. Treating $sin{2varphi_1}$ and $cos{2varphi_1}$ as independent parameters, we obtain $sin{2varphi_1} = 0.43pm 0.27({rm stat.})pm 0.08({rm syst.})$ and $cos{2varphi_1} = 1.06pm 0.33({rm stat.})^{+0.21}_{-0.15}({rm syst.})$. The results are obtained with a full data sample of $772 times 10^6 Bbar{B}$ pairs collected near the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.
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