Joerg Marks
Recently, the B factory experiments BABAR and Belle as well as the CDF collaboration found evidence for mixing in the D meson system. The current status (beginning of summer 2008) of the experimental results of D mixing is summarized.
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We summarise results of analyses of D0 meson mixing parameters performed by the BaBar collaboration.
The BaBar and Belle collaborations have recently found evidence for mixing within the D meson system. We present some of the mixing search techniques used by BaBar and their status as of the beginning of the summer 2007. These have culminated in a measurement in the K decay final state of the D that is inconsistent with the no-mixing hypothesis with a significance of 3.9 standard deviations.
Recent BaBar measurements on lifetime and mixing of B mesons are reported. Various techniques are used, ranging from the full reconstruction of hadronic B decays, to partial reconstruction techniques, and to a totally inclusive approach with dilepton events. The results presented are based on a data sample collected by BaBar during the 1999-2000 data taking, and should be considered as preliminary.
Evidence from the \babar, Belle and CDF experiments for the phenomenon of \dzdzb\ oscillations is reviewed. A summary is made of the current understanding of the parameters defining the mixing of mass eigenstates that give rise to the oscillations. Results of searches for CP violation induced by mixing, are given, and estimates for the precision of measurements that can be expected in future experiments are made.
The $B^0\bar{B^0}$ oscillation frequency $Δm_d$ has been measured with the BaBar detector at the PEP-II asymmetric $B$ factory with different experimental techniques. The discussion here is focused on the recent simultaneous measurement of $Δm_d$ and $τ_{B^0}$ with exclusively reconstructed $B^0 \to D^{*-}l^+ν_l$ decays, based on 23 million $B\bar{B}$ pairs collected by BaBar. The measurements of $Δm_d$ with fully reconstructed hadronic decays and with dilepton events are also reviewed. The average BaBar result is $Δm_d = 0.500 \pm 0.008 \pm 0.006$ $ps^{-1}$.
Time-dependent B0-antiB0 flavor oscillations and B0 and B+ lifetimes are studied in a sample of fully reconstructed B mesons collected with the BaBar detector, running at the PEP-II asymmetric e+e- B Factory with center-of-mass energies near the Upsilon(4S) resonance. This is the first time that time-dependent mixing and lifetime measurements have been performed at Upsilon(4S) energies.
We present the measurements of the CKM matrix parameters Vub, Vcb and of the B mixing oscillation frequency with the BaBar experiment at the asymmetric B-factory PEPII. Data were collected in the years 2000-2002 and the total available statistics corresponds to 91 fb-1. The Vub, Vcb measurements utilize both inclusive and exclusive semileptonic decays of the $B$ meson. The Delta(md) parameter is measured by using the time evolution of the B, determined from the flight length difference between the two B mesons.
Preliminary limits on the D^0 mixing parameter y = ΔΓ/ 2 Γare obtained using about 57.8 fb^-1 of data collected by BaBar in 2000 and 2001:y = (1.4 \pm 1.0 (stat.) +0.6 -0.7 (syst.))%. y is extracted, provided that CP is conserved, by measuring separately the D^0 lifetime for the Cabibbo-suppressed decay modes K- K+, π- π+ and the Cabibbo-favoured mode K- π+. Backgrounds are suppressed by D*-tag and particle identification requirements.
A summary of the results of several recent studies of charm mixing is presented. A number of different methods were used, including the measurement of lifetime ratios for final states of different CP, time dependence of wrong-sign hadronic decays, fits to time-dependent Dalitz plots, and searches for wrong-sign semi-leptonic decays. Taken together, they suggest mixing is of order 1%. The status of searches for indirect CP violation is also reported.
We report a preliminary result for D0-D0bar mixing and the doubly Cabibbo suppressed decay rate R_D based on an analysis of D0 -> K+ pi- decays from 57.1 inverse fb of data collected at or just below the Y(4S) resonance with the BaBar detector at the PEP-II collider. We set 95% confidence limits for the mixing parameters x'^2 and y' and find that our result is compatible with no mixing and no CP violation. In the limit of no mixing we find the doubly Cabibbo suppressed decay rate R_D = (0.357 +- 0.022 (stat.) +- 0.027 (syst.))% and the CP violating asymmetry A_D = 0.095 +- 0.061 (stat.) +- 0.0…
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 describe measurements of CP and CPT violation parameters in B^0B^0bar oscillations, performed at BaBar by using BBbar events collected at the Y(4S) mass peak. These are obtained from two different B-reconstruction methods, namely: searching for two inclusive semileptonic B^0 decays in an event or partially reconstructing one of the B^0 mesons in the D* l nu_l channel. The results are in agreement with one another and with the most recent theoretical calculations in the Standard Model scenario.
With 12.3 fb-1 collected by the BaBar experiment in 2001, the mixing parameter y = Delta(Gamma)/(2 Gamma) is determined from the ratio of the D0 lifetimes measured in the D0 --> K- pi+ and in the D0 --> K- K+ decay modes. The preliminary result y = (-1.0 +- 2.2(stat.) +- 1.7(syst.))% is obtained. Also presented is the status of measuring the mixing parameters y and x^2 = [Delta(M)/Gamma]^2 from a simultaneous fit to the time evolution of the decay time distributions of Cabibbo-favored right-sign (D0 --> K- pi+) and doubly Cabibbo-suppressed wrong-sign (D0 --> K+ pi-) decays. The wrong-sign dec…
Recent results from BaBar and Belle experiments on $B \bar B$ mixing and $\sin 2ϕ_1$ are presented. Accuracy of $Δm_d$ measurements has reached 1.2%. Higher order effects within the Standard Model or possible new physics effect that might appear in the $B \bar B$ mixing through non-zero $ΔΓ/Γ$, CP violation, or $CPT$ violation have been explored. The BaBar and Belle results on $\sin 2ϕ_1$ from the $b \to c \bar{c} s$ modes are in good agreement with each other and a combined result with an accuracy of 8% is in good agreement with a global CKM fit. A simple average of the $\sin 2ϕ_1$ values tha…
The BABAR detector, which operates at the SLAC PEPII asymmetric e+e- collider at energies near the Y(4S) resonance has collected about 23M B-anti-B pairs in year 2000. Based on this data sample, we present the first study of sin(2b), with samples of B^0 --> J/psi K0S, B^0 --> psi(2S) K0S and B^0 --> J/psi K0L decays. The measured value is 0.34+-0.20+-0.05. In addition, we present preliminary measurements of charged and neutral B meson lifetimes and B^0-anti-B^0 oscillation frequency.
With an integrated luminosity of 7.7 fb-1 collected on resonance by BABAR at the PEP-II asymmetric B Factory, we measure the difference in mass between the neutral B eigenstates, Delta(m_d), to be (0.507+/-0.015+/-0.022)x 10^{12} hbar s^{-1} with dileptons events and present preliminary results for the B^0 lifetime, tau(B^0) = 1.55+/-0.05+/-0.07 ps and tau(B^0) = 1.62+/-0.02+/-0.09 ps obtained from partial reconstruction of the two B^0 decay processes respectively B^0-->D^{*-}pi^+ and B^0-->D^{*-} l^+ nu_l.
The BaBar collaboration has analysed 60M BB_ pairs collected at the Upsilon (4S) resonance at the PEP II asymetric collider at SLAC. Using this data sample we have measured the CP violation parameters sin (2beta)=0.75+/- 0.09 (STAT) +/-0.04 (SYST) and lambda =0.92+/- 0.06 (STAT) +/- 0.02 (SYST) from B0 to cc_+K*0 + c.c. decays. From charmless 2-body B decays we measure A_Kpi =-0.05 +/- 0.06 +/- 0.01(-0.14,+0.05), S_pipi = -0.01 +/- 0.37 +/- 0.07(-0.66,+0.62), C_pipi =-0.02 +/- 0.29 +/- 0.07(-0.54,+0.48). A number of B lifetime and mixing parameters, extracted from subsamples of this data set, …
We report the observation of CP violation in the $B^0$ meson system. Using a novel technique for time-dependent measurements, we measure a non-zero value for the CP-violating amplitude $\sin 2β$ at the 4.1 $σ$ level. We also report on precision measurements of the $B^+$ and $B^0$ lifetimes and the $B^0\bar{B}^0$ mixing frequency $Δm_d$ obtained with the same technique and on a first measurement of the time-dependent CP-violating amplitude in $B^0\to π^+π^-$ decays.
The BaBar detector at the PEP-II asymmetric B Factory at SLAC collected a sample of 23M B-anti-B pairs in the years 1999 and 2000. Using this data sample, we measure the amplitude of the time-dependent CP-violating asymmetry in neutral B decays to the CP eigenstates B0 --> J/psi K0S, B0 --> psi(2S) K0S and B0 --> J/psi K0L. We find a value of sin2beta = 0.34 +/- 0.20 (stat) +/- 0.05 (syst). We also present preliminary measurements of the B^0-anti-B^0 oscillation frequency and of the lifetimes of charged and neutral B mesons.
We report on a measurement of D0-D0bar mixing and a search for CP violation in the D0->K+K-, pi+pi- and K+-pi-+ channels. We use D0's coming from D*+ decays, so that the flavour of the D0 at production is tagged by the charge of the pion that is also emitted. We also use an independent set of D0's coming directly from the hadronization of the charm quark, but in this case the flavour of the charmed meson is not known. We analyze events collected by the BaBar experiment at the PEP-II asymmetric-energy e+e- collider, corresponding to an integrated luminosity of 468 fb-1. We measure the mixing pa…
We present evidence for D0-D0bar mixing in $D^0 \to K^{+}π^{-}$ decays from 384 fb^{-1} of e+e- colliding-beam data recorded near sqrt(s)=10.6 GeV with the Babar detector at the PEP-II storage rings at SLAC. We find the mixing parameters ${x^{\prime}}^2 = [-0.22 \pm 0.30 (stat.) \pm 0.21 (syst.)] \times 10^{-3}$ and $y^{\prime} = [9.7 \pm 4.4 (stat.) \pm 3.1 (syst.)] \times 10^{-3}$, and a correlation between them of -0.94. This result is inconsistent with the no-mixing hypothesis with a significance of 3.9 standard deviations. We measure $R_{\rm D}$, the ratio of doubly Cabibbo-suppressed to …
Mixing and CP violation in charm meson decays provide a unique probe of possible physics beyond the standard model. In this paper, we give a brief review of the current measurements from the BABAR experiment.
In this proceedings we present a measurement of mixing, and searches for direct and indirect CP asymmetries in the charm sector using the full \babar data sample of $469 \invfb$. Searches for direct CP asymmetries have been performed in the $D^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, $D_s^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, $D_s^{\pm}\to K^0_{\scriptscriptstyle S} π^\pm$, and $D^{\pm} \to K^+ K^- π^\pm$ decay channels, with both model-dependent and model-independent approaches being exploited for the last mode. The mixing measurement and the search for indirect CP asymmetry have b…
CP violation in B0B0bar mixing is characterized by the value of the parameter |q/p| being different from 1, and the Standard Model predicts this difference to be smaller than 10^{-3}. We present a measurement of this parameter using a partial reconstruction of one of the B mesons in the semileptonic channel D*- l+ nu_l, where only the hard lepton and the soft pion from the D*- --> D0bar pi- decay are reconstructed. The flavor of the other B is determined by means of lepton tagging. The determination of |q/p| is then performed with a fit to the proper time difference of the two B decays. We use…
Using a data sample of 62 million \FourS\to B\Bbar decays collected between 1999 and 2001 by the BaBar detector at the PEP2 asymmetric-energy B Factory at SLAC we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the flavour of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin(2 beta), is derived from the decay time distributions. We measure sin(2 beta) = 0.75 \pm 0.09 (stat) \pm 0.04 (syst) and |λ| = 0.92 \pm 0.06 (sta…
Results of recent searches for new physics in CP violation in charm decays from the BABAR experiment are presented. These results include a measurement of $D^0$ - $\bar{D}^0$ mixing and searches for CP violation in two-body $D^0$ decays, a search for CP violation in the charm decays $D^{\pm} \to K^0_S K^{\pm}$ and $D^{\pm}_s \to K^0_S K^{\pm}$, $K^0_S π^{\pm}$, and a search for direct CP violation in the singly-Cabibbo suppressed $D^{\pm} \to K^+ K^- π^{\pm}$ decays. These studies are based on the final dataset collected by BABAR at the PEP-II B factory at SLAC in the period 1999-2008. No evid…
We report several recent updates from the BABAR Collaboration on the matrix elements $|V_{cb}|$, $|V_{ub}|$, and $|V_{td}|$ of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix, and the angles $β$ and $α$ of the unitarity triangle. Most results presented here are using the full BABAR $Υ(4S)$ data set.
The BaBar and Belle experiments have recently presented evidence for D-Dbar mixing. We explain the following points: (i) The measurements imply width difference $y \sim 0.01$. In the limit of small CP violation, the CP-odd state is longer-lived; (ii) $y\sim0.01$ is consistent with the Standard Model. It suggests that SU(3) breaking from phase space effects is likely to play a major role; (iii) There is no evidence for either large mass splitting or CP violation. Consequently, there is no hint for new physics; (iv) The stronger bounds on the mass splitting and on CP violation imply that, if squ…
This article presents a model independent search for an additional, mostly sterile, Heavy Neutral Lepton (HNL), that is capable of mixing with the Standard Model $τ$ neutrino with a mixing strength of $|U_{τ4}|^{2}$, corresponding to the absolute square of the extended Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix element. Data from the \babar~ experiment, with a total integrated luminosity of $424~ \text{fb}^{-1}$, are analyzed using a kinematic approach that makes no assumptions on the model behind the origins of the HNL, its lifetime or decay modes. No significant signal is found. Upper lim…
Based on a dataset acquired by the BaBar experiment running on and near the $Υ(4S)$ resonance from 1999-2002, limits are set on the rate of $D^0$-- $\kern 0.2em\bar{\kern -0.2em D}{}^0$ mixing using the decay mode $D^{*+} \to D^0 π^{+}$, followed by a semi-leptonic decay of the $D^0$. Results are compared to previous BaBar analysis using hadronic decays. We also report on a search for the flavor-changing neutral current decays $D^0 \to e^{+} e^{-}$ ($μ^{+} μ^{-}$) and the lepton-flavor violation decays $D^0 \to e^{\pm} μ^{\mp}$.
We overview recent measurements in B -> rho rho decays which are based on data samples collected at the PEP-II and KEKB asymmetric-energy e+e- colliders with the BABAR and Belle detectors. Special emphasis is given to the determination of the CP-violating coefficients A and S from an analysis of B -> rho+ rho- decays. The values of A and S, branching fractions, and longitudinal polarization fractions of B -> rho rho decays are used to constrain the Cabibbo-Kobayashi-Maskawa phase alpha/phi2 using an isospin analysis; the solution consistent with the standard model is 71 deg. < alpha < 113 deg.…
We report on measurements of branching fractions for several hadronic tau decays to final states with kaons, which can be used to determine the strange quark mass and the element |V_us| of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are obtained from data collected with the BaBar and Belle detectors at the PEP-II and KEKB asymmetric-energy e+e- colliders at SLAC and KEK, respectively, both operating at center-of-mass energies near the Y(4S) resonance.
Recent results on B mixing and CP violation from the B-factory experiments, BABAR and Belle are summarized.
We review searches for mixing and CP violation in the D0-D0bar system and discuss the first evidence for mixing recently obtained by the Belle and BABAR collaborations. We also present world average values for the mixing parameters x=Delta m/Gamma and y=Delta Gamma/(2 Gamma) as calculated by the Heavy Flavors Averaging Group.
I present three recent results from searches for exotic physics at the BaBar/PEP-II B-factory. These results span many of the samples produced at the B-factory, including B mesons, tau leptons, and Upsilon(3S) mesons. We have searched for CPT-violation in B mixing and find no significant deviation from the no-violation hypothesis. We have also searched for lepton-flavor-violating decays of the tau using tau- -> omega l- and tau- -> l+ l- l+ and their charge conjugates. We find no evidence for these processes and set upper limits on their branching fractions. Finally, we have searched for a low…
Mixing in the D0 system may provide a sensitive probe for new physics beyond the Standard Model (SM) but has so far eluded experimental observation. The SM predictions are typically small (< 10^{-3}) for the mixing parameters x, y which, in the absence of charge-parity (CP) symmetry violation, measure the mass (x= Delta(m)/Gamma) and lifetime (y= Delta(Gamma)/2Gamma) difference of the CP eigenstates in the D0 system. The asymmetric B-factory experiments BABAR and Belle open up the opportunity of measuring x, y with unprecedented statistical precision and sample purities. Results from BABAR and…
We measure the rate of D0-D0bar mixing with the observable yCP=(tauKpi/tauKK)-1, where tauKK and tauKpi are respectively the mean lifetimes of CP-even D0->K+K- and CP-mixed D0->K-pi+ decays, using a data sample of 384/fb collected by the Babar detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D0 and D0bar decays where the inital flavor of the decaying meson is not determined, we obtain yCP = [1.12 +/- 0.26 (stat) +/- 0.22 (sys)]%, which excludes the no-mixing hypothesis at 3.3 sigma, including both statistical and systematic uncertainties. This result is in good agreeme…
This article gives an overview of the recent searches and measurements of $b\to d$ penguin transitions with the BaBar experiment. The branching fraction of these decays in the Standard Model (SM) is expected to be a factor of 10 or more lower than the corresponding $b\to s$ penguin transitions, but a deviation from the SM prediction would be an equally striking sign of new physics. The exclusive decay $B\toπ\ell\ell$ is searched by BaBar with no excess over the background found. The BaBar measurement of $B\to(ρ,ω)γ$ provides the first evidence of $B^+\toρ^+γ$, is in good agreement with the pre…
We present results of a search for CP violation in B0B0bar mixing with the BABAR detector. We select a sample of B0-->D*-Xl+ nu decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other B meson in the event. We determine the CP violating asymmetry ACP = (N(B0B0) - N(B0bar B0bar))/(N(B0B0) + N(B0bar B0bar))=(0.06+-0.17+0.38-0.32)%, corresponding to delta_CP =1 - |q/p| =(0.29+-0.84+1.88 -1.61)*10^-3.
We present evidence of $D^0$-$\bar{D^0}$ mixing using a time-dependent amplitude analysis of the decay D0->K+pi-pi0 in a data sample of 384 fb^-1 collected with the BaBar detector at the PEP-II e+e- collider at SLAC. Assuming CP conservation, we measure the mixing parameters x'_{Kpipi0} = [2.61^{+0.57}_{-0.68} (stat.) +- 0.39 (syst.)]%, y'_{Kpipi0} = [-0.06 ^{+0.55}_{-0.64} (stat.) +- 0.34 (syst.)]%. The confidence level for the data to be consistent with the no-mixing hypothesis is 0.1%, including systematic uncertainties. This result is inconsistent with the no-mixing hypothesis with a signi…
Neutrino oscillations were discovered by atmospheric and solar neutrino experiments, and have been confirmed by experiments using neutrinos from accelerators and nuclear reactors. It has been found that there are large mixing angles in the $ν_e \to ν_μ$ and $ν_μ\to ν_τ$ oscillations. The third mixing angle $θ_{13}$, which parameterizes the mixing between the first and the third generation, is constrainted to be small by the CHOOZ experiment result. The T2K experiment is a long baseline neutrino oscillation experiment that uses intense neutrino beam produced at J-PARC and Super-Kamiokande detec…
A brief overview of flavour-changing phenomena is presented. The main topics discussed are the universality and Lorentz structure of the leptonic charged-current couplings, our present knowledge of the quark-mixing matrix and the future prospects for CP--violation studies.
We present a measurement of $D^0$-$\D0bar$ mixing parameters using the ratios of lifetimes extracted from samples of $D^0$ mesons decaying to $K^-π^+$, $K^-K^+$, and $π^-π^+$. Using 91 ${\rm fb}^{-1}$ of data collected by the BaBar detector at the PEP-II asymmetric-energy $B$ Factory, we obtain a value $Y = (0.8 \pm 0.4 ({\rm stat.}) {}^{+0.5}_{-0.4} ({\rm syst.}))$%, which, in the limit of CP conservation, corresponds to the mixing parameter $y = ΔΓ/2Γ$. Using the difference in lifetimes of $D^0$ and $\D0bar$ mesons, we obtain the CP-violation parameter $ΔY = (-0.8 \pm 0.6 ({\rm stat.}) \pm 0…
The Belle II experiment is under construction at the KEK laboratory in Japan. Belle II will study e+e- collisions at or near the Upsilon(4S) resonance with the goal of collecting 50 ab-1 of data, which is a large increase over that recorded by the Belle and BaBar experiments. This data will provide a large sample of charm meson decays. In this report we present the expected sensitivity of Belle II for measuring time-dependent mixing and CP violation in the D0-D0bar system. We focus on measurements of D0-> K+ pi-, D0-> K+ pi- pi0, and D0-> K0_S pi+ pi- decays.
We provide an overview of the latest progress in the study of CP violation and mixing in the $B$ meson decays. Studying the $B^0_d \to J/ψK^0_S$ and $B^0_s \to J/ψϕ$ decays, we focus on the determination of the mixing phases $ϕ_d$ and $ϕ_s$, including hadronic uncertainties with the help of the data. CP violation in the non-leptonic decays $B \to πK$ and $B^0_s \to D_s^{\mp} K^{\pm}$ indicate puzzling patterns. Could these puzzles indicate New Physics?
We report the recent measurements of $B^0\to J/ψπ^0$ and other CP violation modes based on the data collected by the Belle experiment at the KEKB collider. The CP asymmetry parameters for the decay $B^0\to J/ψπ^0$ have previously been measured by BaBar and Belle experiments, but the results of mixing induced CP asymmetry $[S=-η_f\sin(2ϕ_1)]$ were not in good agreement with each other. Furthermore, the BaBar result lies outside the physically allowed region. Previous Belle measurements were based on $535\times10^6$ $B\bar{B}$ pairs. We updated the measurements using the final Belle data set of …
Based on an 87-fb$^{-1}$ dataset collected by the Babar detector at the PEP-II asymmetric-energy $B$-Factory, a search for $D^{0}$--$\bar{D}^{0}$ mixing has been made using the semileptonic decay modes $D^{*+} \to π^{+} D^{0}, D^{0} \to K^{(*)}eν$ (+c.c.). The use of these modes allows unambiguous flavor tagging and a combined fit of the $D^{0}$ decay time and $D^{*+}$--$D^{0}$ mass difference ($ΔM$) distributions. The high-statistics sample of unmixed semileptonic $D^{0}$ decays is used to model the $ΔM$ distribution and time-dependence of mixed events directly from the data. Neural networks …
The BaBar and Belle collaborations have recently reported evidence for $D^0-\bar D^0$ mixing. This measurement provides the first significant constraint on FCNC in the up-quark sector for non-universal $Z^\prime$ models. Attributing the observed $D-\bar D$ mixing to new physics, we comment on the resulting rare $D$ and $t$ decays. We also show that a CP violating semileptonic asymmetry as large as $\sim 30%$ is allowed by the experimental results.
We present a measurement of D0-D0bar mixing and CP violation using the ratio of lifetimes simultaneously extracted from a sample of D0 mesons produced through the flavor-tagged process D*+ -> D0 pi+, where D0 decays to K-+pi+-, K-K+, or pi-pi+, along with the untagged decays D0 -> K-+pi+- and D0 -> K-K+. The lifetimes of the CP-even, Cabibbo-suppressed modes K-K+ and pi-pi+ are compared to that of the CP-mixed mode K-+pi+- in order to measure yCP and DeltaY. We obtain yCP = [0.72 +- 0.18 (stat) +- 0.12 (syst)]% and DeltaY = [0.09 +- 0.26 (stat) +- 0.06 (syst)]%, where DeltaY constrains possibl…
An overview of selected experimental results in the field of $D^0$-$\bar{D}^0$ oscillations is presented. The average results for the mixing parameters, $x=(0.89\pm{0.26\atop 0.27})%$ and $y=(0.75\pm{0.17\atop 0.18})%$, exclude the no-mixing hypothesis at the level of 6.7 standard deviations. No sign of CP violation in the $D^0$ system is observed. The measurements impose constraints on the parameter space of many New Physics models.
Recently Belle has established the 90% confidence level (CL) upper limit $\b < 9.4 \times 10^{-7}$ for the branching ratio for $B^0\to J/ψϕ$, a process expected to be suppressed by the Okubo-Zweig-Iizuka (OZI) rule disfavoring disconnected quark diagrams. We use information on $ω$--$ϕ$ mixing to establish likely lower bounds on this and related processes. We find that the Belle result is about a factor of five above our limit, while other decays such as $B^0 \to \bar D^0 ϕ$ and $B^+ \to π^+ ϕ$, for which upper limits have been obtained by BaBar, could be observable with similar improvements in…
We present measurements from Belle and BABAR of the time-dependent CP-violation parameters S and C in B->eta'K0 decays. Both experiments observe mixing-induced CP violation with a significance of more than 5 standard deviations in this b-> s penguin dominated mode. We also compare with theoretical expectations and discuss the latest results for SU(3)-related decays which are useful for obtaining bounds on the expected values of S and C.
In these proceedings, we give a summary of the experimental results from CLEO, Belle, BaBar and CDF collaboration about $D^0-\bar{D}^0$ mixing and CP violation in self-conjugated-three-body decays $D^0\rightarrow K_S^0hh$ (where $h$ can be $π$ or $K$). We report preliminary results of measurement of $D^0-\bar{D}^0$ mixing and indirect CP violation in $D^0\rightarrow K_S^0π^+π^-$ decays using full data sample collected by Belle detector at KEKB asymmetric-energy $e^+e^-$ collider: give values for $x=(0.56\pm0.19^{+0.03+0.06}_{-0.09-0.09})%$, $y=(0.30\pm0.15^{+0.04+0.03}_{-0.05-0.06})%$, $|q/p|=…
The noteworthy BaBar and Belle evidence for $D^0$-$\bar{D}^0$ mixing motivates us to study its impact on $D^0\to K^{*\pm} K^\mp$ decays and their CP-conjugate processes. We show that both the $D^0$-$\bar{D}^0$ mixing parameters ($x$ and $y$) and the strong phase difference between $\bar{D}^0\to K^{*\pm}K^\mp$ and $D^0\to K^{*\pm}K^\mp$ transitions ($δ$) can be determined or constrained from the time-dependent measurements of these decay modes. On the $ψ(3770)$ and $ψ(4140)$ resonances at a $τ$-charm factory, it is even possible to determine or constrain $x$, $y$ and $δ$ from the time-independe…
We review the experimental status of Bs mixing. After a brief historical overview, current studies of the time dependence of Bs oscillations are described, with an emphasis on the different experimental techniques used by the ALEPH, CDF, DELPHI, OPAL, and SLD Collaborations. To conclude, the outlook for future experiments is presented.
The large decay rate observed by Belle for $B^+\toψ(3770)K^+$, which is comparable to $B^+\toψ(3686)K^+$, might indicate either an unexpectedly large S-D mixing angle $|θ|\approx 40^o$ or the leading role of the color-octet mechanism in D-wave charmonium production in B decay. By calculating the production rate of $ψ(3770)$ in the continuum $e^+e^-$ annihilation at $\sqrt{s}=10.6$ GeV with these two possible approaches (i.e. the large S-D mixing and the color-octet mechanism), we show that the measurement for this process at Belle and BaBar may provide a clear cut clarification for the two app…
We present an overview of recent progress in the phenomenological study of neutrino masses, lepton flavor mixing and CP violation. We concentrate on the model-independent properties of massive neutrinos, both in vacuum and in matter. Current experimental constraints on the neutrino mass spectrum and the lepton flavor mixing parameters are summarized. The Dirac- and Majorana-like phases of CP violation, which are associated respectively with the long-baseline neutrino oscillations and the neutrinoless double beta decay, are discussed in detail. The seesaw mechanism, the leptogenesis scenario an…
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