Improved measurement of the CKM angle gamma in B^-+ -> D^(*) K^(*)-+ decays with a Dalitz plot analysis of D decays to K_S^0 pi^+ pi^- and K_S^0 K^+ K^-
The BABAR Collaboration, B. Aubert
备注：
22 pages, 13 figures, 6 tables. Accepted by Phys. Rev. D
We report on an improved measurement of the Cabibbo-Kobayashi-Maskawa {\it CP}-violating phase $γ$ through a Dalitz plot analysis of neutral $D$ meson decays to $K_S^0 π^+ π^-$ and $K_S^0 K^+ K^-$ in the processes $B^\mp \to D K^\mp$, $B^\mp \to D^* K^\mp$ with $D^* \to Dπ^0,Dγ$, and $B^\mp \to D K^{*\mp}$ with $K^{*\mp} \to K_S^0 π^\mp$. Using a sample of 383 million $B\bar{B}$ pairs collected by the BABAR detector, we measure $γ=(76 \pm 22 \pm 5 \pm 5)^\circ$ (mod $180^\circ$), where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the uncertainty on the description of the Dalitz plot distributions. The corresponding two standard deviation region is $29^\circ < γ< 122^\circ$. This result has a significance of direct {\it CP} violation ($γ\ne 0$) of 3.0 standard deviations.
We present a measurement of the angle phi1 of the CKM Unitarity Triangle using time-dependent Dalitz analysis of D -> Ks pi+ pi- decays produced in neutral B meson decay to a neutral D meson and a light meson (B0bar -> D(*) h0). The method allows a direct extraction of 2phi1 and, therefore, helps to resolve the ambiguity between 2phi1 and pi-2phi1 in the measurement of sin 2phi1. We obtain sin 2phi1=0.78+-0.44+-0.22 and cos 2phi1=1.87+0.40+0.22 -0.53-0.32 The sign of cos 2phi1 is determined to be positive at 98.3% C.L.
Present and future contributions of the CLEO experiment to the study of $D$ Dalitz plots are presented. Such Dalitz plots can be of help in determining weak phases from $B \to D K$ decays.
We report on the Dalitz plot analyses of B^- \to D^+ π^-π^-, B^+ \to π^+ π^- π^+ and D^+_s \to π^+ π^- π^+. The Dalitz plot method and the most recent BABAR results are discussed.
We present a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase gamma with a Dalitz analysis of neutral D-meson decays to the K^0_s pi^- pi^+ final state from B^+/- -> D^{(*)}K^+/- decays, using a sample of 347 million B\bar{B} events collected by the BaBar detector. We measure gamma = (92 +/- 41 +/- 11 +/- 12)deg, where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the Dalitz model uncertainty. For the ratios r_B^{(*)} between the magnitudes of amplitudes A(B- -> D^{(*)0}K-) and A(B- ->\bar{D}^{(*)0} K-) we obtain the…
We describe Dalitz plots arising in studies of $D$-meson decays, and what we have learned from them in recent years. After some mention of technique and history, we focus on decay of the $D^\pm$ and $D_s^\pm$ mesons to the $K^-K^+π^\pm$ final state, and on $D_s^\pm$ decay to $π^+π^-π^\pm$. Some mention of other Dalitz plots involving $D$-meson decays is also made.
We report recent results of the Dalitz plot analyses of D and D_S decays performed by the BaBar collaboration, and point out some of the important applications of these results.
A value of (-6.1 +- 0.9_{stat} +- 0.5_{syst})*10^{-3} is obtained for the quadratic slope parameter h in the K_L -> 3π^0 decay Dalitz plot at the NA48 experiment at the CERN SPS. The result is based on 14.7*10^6 fully reconstructed K_L -> 3π^0 -> 6γdecays. This is the most precise measurement of any of the Dalitz plot slope parameters in the charged and neutral kaon decays so far.
A precise measurement of the angle $α$ in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract $α$ is provided by B$^0 \to ρπ$ decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tree and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on $α$ better than 5$^{\circ}$.
We present preliminary results on the measurement of the I=1/2 $K π$ $\mathcal{S}$-wave through a model independent partial wave analysis of $η_c$ decays to $K^0_S K^+ π^-$ and $K^+ K^- π^0$ produced in two-photon interactions. We also perform a Dalitz plot analysis of the $J/ψ$ decays to $π^+ π^- π^0$ and $K^+ K^- π^0$ produced by the initial state radiation process.
A Dalitz plot analysis of the D0 hadronic decays D0 -> K0 K- pi+, D0 -> K0bar K+ pi- and D0 -> K0bar K+ K- is presented. This analysis is based on a data sample of 22 fb-1 collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC running on or near the Y(4S) resonance. The events are selected from continuum e+ e- annihilations using the decay D*+ -> D0 pi+. Preliminary measurements of the branching fractions of the above hadronic decays are obtained. Preliminary estimates of fractions and phases for resonant and nonresonant contributions to the Dalitz plot are also pr…
Using data collected by the high energy photoproduction experiment FOCUS at Fermilab we performed a Dalitz plot analysis of the Cabibbo favored decay D+ to K-pi+ pi+. This study uses 53653 Dalitz-plot events with a signal fraction of ~ 97%, and represents the highest statistics, most complete Dalitz plot analysis for this channel. Results are presented and discussed using two different formalisms. The first is a simple sum of Breit--Wigner functions with freely fitted masses and widths. It is the model traditionally adopted and serves as comparison with the already published analyses. The seco…
The NA48/2 experiment at the CERN SPS has collected an unprecedented sample of $K^\pm\to3π$ decays. The high statistics and the good resolution of the detectors allow a unique investigation of the detailed phase space distributions of these decays. The effects of final state pion rescattering observed in the Dalitz plot distribution of the $K^\pm\toπ^\pmπ^0π^0$ decays turned out to be a powerful tool for extraction of the S-wave $ππ$ scattering lengths. The large statistics also allowed a precise measurement of the Dalitz plot slope parameters for the $K^\pm\to3π^\pm$ decays.
A Dalitz plot analysis of approximately 12500 D0 events reconstructed in the hadronic decay D0-->K0bar K+ K- is presented. This analysis is based on a data sample of 91.5 fb-1 collected with the BaBar detector at the PEP-II asymmetric-energy e+ e- storage rings at SLAC running at center-of-mass energies on and 40 MeV below the Y4S resonance. The events are selected from e+ e- --> c cbar annihilations using the decay D*+ --> D0 pi+. The following ratio of branching fractions has been obtained: BR = Gamma(D0-->K0bar K+ K-)/Gamma(D0-->K0bar pi+ pi-) = (15.8+/-0.1(stat.)+/-0.5(syst.)x 10-2 Estimat…
We present a preliminary measurement of CP-violation parameters in the decay B0->K+K-Ks, using approximately 465 million BBbar events collected by the BABAR detector at SLAC. Reconstructing the neutral kaon as Ks->pi+pi- or Ks->pi0pi0, we analyze the Dalitz plot distribution and measure fractions to intermediate states. We extract CP parameters from the asymmetries in amplitudes and phases between B0 and B0bar decays across the Dalitz plot. From a fit to the whole Dalitz plot, we measure beta_eff = 0.44 +/- 0.07 +/- 0.02, A_CP = 0.03 +/- 0.07 +/- 0.02, where the first uncertainties are statist…
We present a study of the dynamics in B0 --> K+ K- K0S decays with approximately 230 million BBbar events collected by the BABAR detector at SLAC. We find that the Dalitz plot distribution is best parameterized with the phi K0S mode, an S-wave K+ K- resonance near 1500 MeV/c^2, and a large non-resonant contribution. We set limits on resonances not included in our model, and study models for the non-resonant contribution.
We have studied the Dalitz plot of the e+ e- --> pi0 pi0 gamma events collected at SQRT(s) ~ M(phi) with the KLOE detector. In the dipion invariant mass (Mpp) region below 700 MeV, the process under study is dominated by the non-resonant process e+ e- --> omega pi0 with omega --> pi0 gamma whereas, for higher Mpp values, the radiative phi decay to the f0(980) is the dominant mechanism. Different theoretical models are used to fit the Dalitz plot, taking also into account a possible contribution of the sigma(600). For each model, we extract the f0(980) mass and its coupling to pipi, KKbar and t…
We perform a Dalitz plot analysis of about 100,000 Ds+ decays to K+ K- pi+ and measure the complex amplitudes of the intermediate resonances which contribute to this decay mode. We also measure the relative branching fractions of Ds+ --> K+ K+ pi- and Ds+ --> K+ K+ K-. For this analysis we use a 384 fb-1 data sample, recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- collider running at center-of-mass energies near 10.58 GeV.
We present a measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B+- -> D K*+- process. Using a 253 fb-1 data sample collected by the Belle experiment, we obtain 56 signal candidates for B+- -> D K*+-, where the neutral D meson decays into K_S pi+ pi-. From a maximum likelihood fit we obtain phi_3=112+-35(stat)+-9(syst)+-11(model)+-8(nonresonant B -> D K_S pi).
We report a Dalitz-plot analysis of the charmless hadronic decays of charged B mesons to the final state K+/- pi+/- pi-/+. Using a sample of 383.2 +/- 4.2 million BBbar pairs collected by the BaBar detector, we measure CP-averaged branching fractions and direct CP asymmetries for intermediate resonant and nonresonant contributions. We find evidence for direct CP violation in the decay B+ -> rho0(770) K+, with a CP violation parameter A_CP = (+44 +/- 10 +/- 4 +5,-13)%.
Results from the Belle and BaBar experiments on measurement of the weak angle phi_3 using a Dalitz plot analysis of the KSpi+pi- decay of the neutral D meson from the B+=>D(*)K(*)+ process are presented. The method employs the interference between D0 and D0bar to extract the angle phi_3, strong phase delta and the ratio r of suppressed and allowed amplitudes.
We report on a search for CP asymmetry in the singly Cabibbo-suppressed decay D+ -> K+ K- pi+ using a data sample of 818 pb-1 accumulated with the CLEO-c detector on the psi(3770) resonance. A Dalitz-plot analysis is used to determine the amplitudes of the intermediate states. We find no evidence for CP violation either in specific two-body amplitudes or integrated over the entire phase space. The CP asymmetry in the latter case is measured to be (-0.03+-0.84+-0.29)%.
FOCUS results from Dalitz plot analysis of D_s+ and D+ to pi+pi-pi+ are presented. The K-matrix formalism is applied to charm decays for the first time to fully exploit the already existing knowledge coming from the light-meson spectroscopy experiments. In particular all the measured dynamics of the S-wave pipi scattering, characterized by broad/overlapping resonances and large non-resonant background, can be properly included. This paper studies the extent to which the K-matrix approach is able to reproduce the observed Dalitz plot and thus help us to understand the underlying dynamics. The r…
We report preliminary results from a study of the decay B0 --> D0bar pi+ pi- using a data sample of 470.9 +/- 2.8 million BBbar events collected with the BaBar detector at the Y(4S) resonance. Using the Dalitz-plot analysis technique, we find contributions from the intermediate resonances D*_2(2460)-, D*_0(2400)-, rho(770)0 and f_2(1270) as well as a pi+ pi- S-wave term, a D0bar pi- nonresonant S-wave term and a virtual D*(2010)- amplitude. We measure the branching fractions of the contributing decays.
We present a preliminary search for D0--anti-D0 mixing using the decays D0 --> K+ pi- pi0, additionally presenting Dalitz-plot distributions and a measurement of the branching ratio for this mode. A new tagging technique is used to produce the doubly Cabibbo-suppressed Dalitz plot, which in turn is used to motivate the method used for the D-mixing search. We analyze 230.4fb-1 of data collected from the BaBar detector at the PEP-II collider. Assuming CP conservation, we find R_M < 0.054% with 95% confidence, and we estimate that the data are consistent with no mixing at a 4.5% confidence level.…
We present constraints on the angle gamma of the Unitarity Triangle with a Dalitz analysis of neutral D decays to K_Spi^+pi^- from the processes B^0 -> barD^0 K^*0 (barB^0 -> D^0 barK^*0) and B0 -> D0 K*0 (barB^0 -> barD^0 barK^*0) with K^*0 -> K^+pi^- (barK^*0 -> K^-pi^+). Using a sample of 371 10^6 BBbar pairs collected with the Babar detector at PEP-II, we measure the angle gamma as a function of r_S, the magnitude of the average ratio between b -> u and b -> c amplitudes. Combining this result with the available information on r_S, we obtain gamma = (162 +- 56) degrees or (342 +- 56) degre…
We present several recent analyses of Dalitz plots from the CLEO-c experiment, including published and preliminary analyses of D+ to pi- pi+ pi+, D+ to K- pi+ pi+, and D0 to K0_{S,L} pi+ pi- decays. More information on these analyses can be found in References [1-3]. New preliminary analyses we present include a search for CP asymmetry in D+ to K+ K- pi+ decays and a Dalitz plot analysis of D0 to K0_{S} pi0 pi0. We report on a search for the CP asymmetry in the singly Cabibbo-suppressed decay D+ to K+ K- pi+ using a data sample of 572 pb^{-1} accumulated with the CLEO-c detector and taken at t…
We perform an analysis of the $D^+\rightarrow K^0_S π^+ π^0$ Dalitz plot using a data set of 2.92 fb$^{-1}$ of $e^+e^-$ collisions at the $ψ(3770)$ accumulated by the BESIII Experiment, in which 166694 candidate events are selected with a background of 15.1%. The Dalitz plot is found to be well-represented by a combination of six quasi-two-body decay channels ($K^0_Sρ^+$, $K^0_Sρ(1450)^+$, $\overline{K}^{*0}π^+$, $\overline{K}_0(1430)^0π^+$, $\overline{K}(1680)^0π^+$, $\overlineκ^0π^+$) plus a small non-resonant component. We also consider a model-independent approach to confirm an obvious pha…
Using a sample of 68 million KL -> 3pi0 decays collected in 1996-1999 by the KTeV (E832) experiment at Fermilab, we present a detailed study of the KL -> 3pi0 Dalitz plot density. We report the first observation of interference from KL->pi+pi-pi0 decays in which pi+pi- rescatters to 2pi0 in a final-state interaction. This rescattering effect is described by the Cabibbo-Isidori model, and it depends on the difference in pion scattering lengths between the isospin I=0 and I=2 states, a0-a2. Using the Cabibbo-Isidori model, we present the first measurement of the KL-> 3pi0 quadratic slope paramet…
We report a measurement of CP-violating asymmetries in B0-->(rhopi)0-->pi+pi-pi0 decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 375 million Y(4S) --> BBbar decays, collected by the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure 26 coefficients of the bilinear form-factor terms occurring in the time-dependent decay rate of the B0 meson. We derive the physically relevant quantities from these coefficients. In particular, we measure a constraint on the angle alpha of the Unitarity Triangle.
We present for the first time a measurement of the weak phase 2b+g obtained from a time-dependent Dalitz plot analysis of B^0 -> D-(+) K0 Pi+(-) decays. Using a sample of approximately 347*10^{6} BBbar pairs collected by the BABAR detector at the PEP-II asymmetric-energy storage rings, we obtain 2b+g = (83 +/- 53 +/- 20) degrees and (263 +/- 53 +/- 20) degrees assuming the ratio r of the b -> u and b -> c decay amplitudes to be 0.3. The magnitudes and phases for the resonances associated with the b -> c transitions are also extracted from the fit.
We report a preliminary measurement of $\cos2β$ in $B^0\to D^{(*)0}h^0$ decays with a time-dependent Dalitz plot analysis of $D^0\to K_Sπ^+π^-$, where $h^0$ is a light neutral meson such as $π^0$, $η$, $η'$ or $ω$. The strong phase variation on the Dalitz plot allows the access to the angle $β$ with only a two-fold ambiguity ($β+π$). Using $311\times 10^{6}$ $B\bar{B}$ pairs collected at the Babar detector, we obtain $\cos2β= 0.54 \pm 0.54 \pm 0.08 \pm 0.18$, $\sin2β= 0.45 \pm 0.36 \pm 0.05 \pm 0.07$, and $|λ| = 0.975^{+0.093}_{-0.085} \pm 0.012 \pm 0.002 $, where the first errors are statisti…
We study the time-dependent Dalitz plot of D->KSpi+pi- in B0->D(*)h0 decays, where h0 is a pi0, eta, eta', or omega meson and D*->Dpi0 using a data sample of 383 X 10^6 Upsilon(4S)->BBbar decays collected with the BABAR detector. We determine cos2beta = 0.42+-0.49+-0.09+-0.13, sin2beta = 0.29+-0.34+-0.03+-0.05, and |lambda| = 1.01+-0.08+-0.02, where the first error is statistical, the second is the experimental systematic uncertainty, and the third, where given, is the Dalitz model uncertainty. Assuming the world average value for sin2beta and |lambda|=1, cos2beta>0 is preferred over cos2beta<…
A Dalitz plot analysis of approximately 13,000 Ds+ decays to pi+pi-pi+ has been performed. The analysis uses a 384 fb-1 data sample recorded by the BaBar detector at the PEP-II asymmetric-energy e+e- storage ring running at center of mass energies near 10.6 GeV. Amplitudes and phases of the intermediate resonances which contribute to this final state are measured. A high precision measurement of the ratio of branching fractions is performed: BR(Ds+ -> pi+pi-pi+)/BR(Ds+ -> K+ K- pi+)=0.199 +/- 0.004 +/- 0.009. Using a model-independent partial wave analysis, the amplitude and phase of the S-wav…
The potentiality of interpreting the D-meson decay-dynamics has revealed itself to be strongly dependent on our understanding of the light-meson sector. The statistics collected by FOCUS is already at a level that manifests parametrization problems for scalar particles. In this paper the first application of the K-matrix approach in the charm sector is illustrated and preliminary results on the D+ and Ds decays to three pions are shown.
We present a measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B->D(*)K process. Using a 253 fb-1 data sample collected by the Belle experiment, we obtain 276 signal candidates for B->DK and 69 candidates for B->D*K, where the neutral D meson decays into K_Spi+pi-. From a combined maximum likelihood fit to the B->DK and B->D*K modes, we obtain phi_3=68+14-15(stat)+-13(syst)+-11(model). The corresponding two standard deviation interval is 22<phi_3<113.
Dalitz analysis is a powerful tool for physics studies within and beyond the Standard Model. In the last decade it has helped to investigate the Heavy Flavor hadronic decay dynamics and is now being applied to extract angles of the CKM Unitarity triangle. To perform such sophisticate analyses we need to model the strong interaction effects. The FOCUS experiment has performed pilot studies in the charm sector through the K-matrix formalism. What has been learnt from charm will be beneficial for future accurate beauty measurements. Experience and results from FOCUS are presented and discussed.
We present a preliminary measurement of CP-violation parameters in the decay B0 -> K+K-K0, using approximately 347 million BBbar events collected by the BABAR detector at SLAC. Reconstructing the neutral kaon as KS -> pi+pi-, KS -> pi0pi0, or KL, we analyze the Dalitz plot distribution and measure fractions to intermediate states. We extract CP parameters from the asymmetries in amplitudes and phases between B0 and B0bar decays across the Dalitz plot. For decays to phiK0, we find beta_eff=0.06 +/- 0.16 +/- 0.05, Acp=-0.18 +/- 0.20 +/- 0.10, where the first uncertainty is statistical and the se…
We report a Dalitz-plot analysis of the charmless hadronic decays of charged B mesons to the final state K+/- pi-/+ pi+/-. Using a sample of 226.0 +/- 2.5 million BBbar pairs collected by the BaBar detector, we measure the magnitudes and phases of the intermediate resonant and nonresonant amplitudes for both charge conjugate decays. We present measurements of the corresponding branching fractions and their charge asymmetries that supersede those of previous BaBar analyses. We find the charge asymmetries to be consistent with zero.
The distribution of the $K^\pm\toπ^\pmπ^+π^-$ decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of $4.71\times 10^8$ fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: $g=(-21.134\pm0.017)\%$, $h=(1.848\pm0.040)\%$, $k=(-0.463\pm0.014)\%$. The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion-pion rescat…
Using 281 pb^{-1} of data recorded by the CLEO-c detector in e^+e^- collisions at the psi(3770), corresponding to 0.78 million D^+D^- pairs, we investigate the substructure of the decay D^+ to pi^- pi^+ pi^+ using the Dalitz plot technique. We find that our data are consistent with the following intermediate states: rho(770)pi^+, f_2(1270)pi^+, f_0(1370)pi^+, f_0(1500)pi^+, f_0(980) pi^+, and sigma pi^+. We confirm large S wave contributions at low pi pi mass. We set upper limits on contributions of other possible intermediate states. We consider three models of the pi pi S wave and find that …
We report the results of a CP violation analysis of the decay B+/- --> D(pipipi0)K+/-, where D(pipipi0) indicates a neutral D meson detected in the final state pi+pi-pi0, excluding K_S pi0. The analysis makes use of 324 million e+e- --> BB events recorded by the BaBar experiment at the PEP-II e+e- storage ring. By analyzing the pi+pi-pi0 Dalitz plot distribution and the B+/- --> D(pipipi0)K+/- branching fraction and decay rate asymmetry, we calculate parameters related to the phase gamma of the CKM unitarity triangle. We also measure the magnitudes and phases of the components of the D0 --> pi…
We present results of a new analysis campaign, which combines the final data samples collected by the B factory experiments BABAR and Belle in single physics analyses to achieve a unique sensitivity in time-dependent \CP\ violation measurements. The data samples contain $(471 \pm 3) \times 10^6 ~B \bar B$ pairs recorded by the BABAR detector and $(772 \pm 11) \times 10^6 ~ B \bar B$ pairs recorded by the Belle detector in $e^+e^-$ collisions at the center-of-mass energies corresponding to the mass of the $Υ(4S)$ resonance at the asymmetric-energy $B$ factories PEP-II at SLAC and KEKB at KEK, r…
We perform a Dalitz plot analysis of the decay Ds to K+K-pi+ with the CLEO-c data set of 586/pb of e+e- collisions accumulated at sqrt(s) = 4.17 GeV. This corresponds to about 0.57 million D_s+D_s(*)- pairs from which we select 14400 candidates with a background of roughly 15%. In contrast to previous measurements we find good agreement with our data only by including an additional f_0(1370)pi+ contribution. We measure the magnitude, phase, and fit fraction of K*(892) K+, phi(1020)pi+, K0*(1430)K+, f_0(980)pi+, f_0(1710)pi+, and f_0(1370)pi+ contributions and limit the possible contributions o…
The decay $η\rightarrow π^+ π^- π^0$ is studied with the KLOE detector, at the DA$ϕ$NE e$^+$e$^-$ collider. Using a data sample corresponding to an integrated luminosity of $1.6$ fb$^{-1}$ a new study of the Dalitz plot is presented.
We present a Dalitz plot analysis of the decay D+ -> K- pi+ pi+ based on 281 pb-1 of e+e- collision data produced at the psi(3770) by CESR and observed with the CLEO-c detector. We select 67086 candidate events with a small, ~1.1%, background for this analysis. When using a simple isobar model our results are consistent with the previous measurements done by E791. Since our sample is considerably larger we can explore alternative models. We find better agreement with data when we include an isospin-two pi+pi+ S-wave contribution. We apply a quasi model-independent partial wave analysis and mea…
We report a measurement of CP-violating asymmetries in $B^0\to(ρπ)^0\toπ^+π^-π^0$ decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 347 million $Υ(4S) \to B\bar{B}$ decays, collected by the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure 26 coefficients of the bilinear form factor terms occurring in the time-dependent decay rate of the \Bz meson and derive the physically relevant quantities from these coefficients. In particular we find a three standard deviation evidence of direct CP-violation in $B^0\toρ^\pmπ^\mp$ …
The resonant substructure in D0 --> K0S pi+ pi- decays is described by a combination of ten quasi two-body intermediate states which include both CP-even and CP-odd eigenstates and one doubly-Cabibbo suppressed channel. We present a formalism that connects the variation in D0 decay time over the Dalitz plot with the mixing parameters, x and y, that describe off-shell and on-shell D0-D0B mixing. We analyze the CLEO II.V data sample and find the parameters x and y are consistent with zero. We limit (-4.7 < x < 8.6)% and (-6.1 < y < 3.5)% at the 95\% confidence level
Using the 9 inverse femtobarn data sample collected with the CLEO II.V detector at the Cornell Electron Storage Ring, we have studied the resonant substructure of the Cabibbo suppressed decay D0 -> pi+ pi- pi0. We observe significant contributions from the rho- pi+, rho+ pi-, rho0 pi0, and non-resonant channels, and present preliminary results of the amplitudes, phases, and fit fractions for these sub-modes. No evidence for the sigma(500) or more massive rho resonances was found. We observe no CP violation, finding Acp = 0.01 +0.09 -0.07 +- 0.09.
In e+e- collisions recorded using the CLEO II.V detector we have studied the Cabibbo suppressed decay of D0 -> pi+pi-pi0 with the initial flavor of the D0 tagged by the decay D*+ -> D0pi+. We use the Dalitz-plot analysis technique to measure the resonant substructure in this final state and observe ρπand non-resonant contributions by fitting for their amplitudes and relative phases. We describe the pipi S-wave with a K-matrix formalism and limit this contribution to the rate to be < 2.5% @95% confidence level, in contrast to the large rate observed in D+ -> pi+pi-pi+ decay. Using the amplitude…
We present preliminary results on the Dalitz plot analysis of $B^0 \to K^+ π^- π^0$ decays. The data sample comprises 213 million $Υ(4S) \to B {\bar B}$ decays collected with the BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We report measurements of the inclusive branching fraction, quasi-two-body fractions and CP-violating charge asymmetries for intermediate states including $K^*(892)^+ π^-$ and $ρ(770)^- K^+$. Observations of $B^0$ decays to the $Kπ$ $S$-wave intermediate states, $K_0^*(1430)^+ π^-$ and $K_0^*(1430)^0 π^0$, are reported. Evidence of the decay $B^0 \to …
We present a measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the K0_S pi+ pi- decay of the neutral D meson from the B+- -> D(*)K(*)+- process. The method employs the interference between D0 and D0bar to extract the angle phi_3, strong phase Delta and the ratio r of suppressed and allowed amplitudes. We apply this method to a 357 fb-1 data sample collected by the Belle experiment. The analysis uses three modes: B+ -> DK+, B+ -> D*K+ with D* -> Dpi0, and B+ -> DK*+ with K*+ -> K0_S pi+, as well as the corresponding charge-conjugate modes. From a combined maximum…
We present Dalitz plot analyses for the decays of $B$ mesons to $D^-D^0K^+$ and $\overline{D}^0D^0K^+$. [Charge conjugate reactions are implicitly assumed throughout.] We report the observation of the $D^*_{s1}(2700)^+$ resonance in these two channels and obtain measurements of the mass $M(D^*_{s1}(2700)^+) = 2699^{+14}_{-7}$ MeV/$c^2$ and of the width $Γ(D^*_{s1}(2700)^+) = 127^{+24}_{-19}$ MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the $D^0K^+$ invariant mass around 2350--2500 MeV/$c^2$ in both decays $B^0 \to D^-D^0K^+$ and $B^+ \to \o…
Bose symmetry and $CPT$ symmetry are two very fundamental symmetries of Nature. However, the validity of these symmetries in diverse phenomena must be verified by experiments. We propose new techniques to probe these two fundamental symmetries in the realm of mesons by using the Dalitz plot of a few three-body meson decays. Since these symmetries are very fundamental in nature, their violations, if any, are expected to be extremely small. Hence observing their violations requires study of a huge data sample. In this context we introduce a new three-dimensional plot which we refer to as the Dal…
We present a measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B->D(*)K process. The method employs the interference between D0 and D0bar to extract both the weak and strong phases. We apply this method to a 140 fb^{-1} data sample collected by the Belle experiment. The analysis uses the modes B->DK and B->D*K, D*->D pi0, where the neutral D meson decays into K_Spi+pi-. We obtain 146 signal candidates for B->DK and 39 candidates for B->D*K. From a combined maximum likelihood fit to the B->DK and B->D*K modes, …
The Laura++ software package is designed for performing fits of amplitude models to data from decays of spin-0 particles into final states containing three spin-0 particles - so-called Dalitz-plot analysis. An overview of the amplitude formalism and its software implementation is given as well as summaries of recently added features and planned future developments.
We present a time-dependent Dalitz plot measurement of CP violation parameters in B0 --> Ks Pi+ Pi- decays. These results are obtained from a large data sample that contains 657 million BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. For the CP violation parameters, we obtain two consistent solutions that describe the data well. The first of these solutions may be preferred by external information from other measurements. There is no evidence for direct CP violation in B0 --> rho0(770) Ks, B0 --> f0(980) Ks and B0 --> K*+(892) P…
We present an updated measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the K^0_S pi+ pi- decay of the neutral D meson produced in B+- ->D(*)K+- decays. The method exploits the interference between D^0 and Dbar^0 to extract the angle phi_3, strong phase delta and the ratio r of suppressed and allowed amplitudes. We apply this method to a 605 fb-1 data sample collected by the Belle experiment. The analysis uses two modes: B+- -> DK+-, and B+- -> D*K+- with D* -> D pi0, as well as the corresponding charge-conjugate modes. From a combined maximum likelihood fit to …
We report on a Dalitz plot analysis of B- -> D+ pi- pi- decays, based on a sample of about 383 million Upsilon(4S) -> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the total branching fraction of the three-body decay: BR(B- -> D+ pi- pi-) = (1.08 +/- 0.03 +/- 0.05) x 10^-3. The masses and widths of D^{*0}_2 and D^{*0}_0, the 2+ and 0+ cubar P-wave states decaying to D+ pi-, are measured: mass_{D^{*0}_2} = (2460.4 +/- 1.2 +/- 1.2 +/- 1.9) MeV/c2, width_{D^{*0}_2} = (41.8 +/- 2.5 +/- 2.1 +/- 2.0) MeV, mass_{D^{*0}_0} = (2297 +/- 8 +/- 5…
The charge asymmetry of the g, h, and k Dalitz plot parameters for $K^{\pm}\toπ^{\pm}π^0π^0$ decays has been measured with 35 GeV/c hadron beams at the 70 GeV IHEP accelerator. The g, h and k values obtained appear to be identical for $K^{\pm}\toπ^{\pm}π^0π^0$ decays within the errors quoted. In particular, the charge asymmetry $A_g = (g^+ - g^-)/(g^+ + g^-)$ of the slope g is equal to $(0.2 \pm 1.9)\cdot 10^{-3}$.
