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.
We report on measurements of time-dependent CP-violation asymmetries in neutral B meson decays to charmonium and charm final states. The results are obtained from a data sample of 467+/-5 million Y(4S)->BBbar decays collected with the BaBar detector at the PEP-II B factory.
A review of recent results concerning decays of charmed mesons, charmed baryons and $τ$ leptons for the Belle and BaBar Experiments is given. The review was presented at the 43$^{rd}$ Rencontres de Moriond (QCD and High Energy Interactions), LaThuile, March 8-15, 2008.
We report recent measurements of rare charmless B decays performed by BaBar. The results are based on the final BaBar dataset of 424 fb^{-1} collected at the PEP-II $B$-factory based at the SLAC National Accelerator Laboratory.
The charmonium-like states, Y(4260), Y(4350), produced via initial state radiation, as well as the X(3872), and Y(3940), produced in B meson decays from the BABAR B-factory are reviewed. These mesons do not seem consistent with conventional charmonium models, and several alternate hypotheses have been proposed to explain these new discoveries.
Large production of the $\ccbar$ pairs and high integrated luminosity make the PEPII B-Factory, an excellent place for studying the charm hadrons. In this paper, we present a few of the most recent results from the BaBar collaboration in the charm sector.
This article summarises measurements of time-dependent CP asymmetries in decays of neutral B mesons to charm final states using data collected by the BaBar detector at the PEP-II asymmetric-energy B-factory. All results are preliminary unless otherwise stated.
We present measurements of branching fraction, polarization and charge asymmetry in charmless hadronic B decays with eta, eta', omega, and b_1 in the final state. All the results use the final BABAR dataset.
We present recent results on charmless hadronic B decays using data collected by the BaBar detector at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center. We report measurements of branching fractions and charge asymmetries in several charmless two-body, three-body, and quasi-two-body decay modes. We also report measurements of polarization in charmless B decays to exclusive final states with two vector mesons.
Belle and BaBar experiments at the KEKB and PEP-II B-factories provide also an excellent environment for spectroscopy studies. In this report we present recent results in the field of charmonium spectroscopy, focusing on new charmonium-like states observed in B decays, and on $J^{PC}=1^{--}$ resonances created in $e^+ e^-$ annihilation through the photon radiative return.
We report recent measurements of branching fractions and charge asymmetries of charmless hadronic B decays using the data collected with the BABAR detector at the PEP-II asymmetric energy e+e- collider.
In this mini-review we report on the most recent progress in charm meson spectroscopy. We discuss the precision measurements performed by the BaBar and CLEO-c experiments in the non strange charm meson part and we present the newly discovered strange charmed meson excited states.
We present searches for rare charm decays of the form $X_c^+ \to h^{\pm} \ell^{\mp} \ell^{(')^+}$, where $X_c^+$ is a charm hadron either $D^+$, $D_s^+$, or $Λ_c^+$, and $\ell^{(')^{\pm}}$ is an electron or muon. These modes are based on 384 $fb^{-1}$ of $e^+ e^-$ annihilation data collected at the $Υ(4S)$ resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We also present the flavor-changing neutral-current decays $D^0 \to e^+e^-$, $D^0 \to μ^+ μ^-$, and $D^0 \to e^{\pm} μ^{\mp}$ that corresponds to an integrated luminosity of 468 $fb^{-1}$ of data. The decay $D^0 \…
This article summarises measurements of time-dependent CP asymmetries in decays of neutral B mesons to charmonium, open-charm and gluonic penguin-dominated charmless final states. Unless otherwise stated, these measurements are based on a sample of approximately 230 million Y(4S) to BBbar decays collected by the BABAR detector at the PEP-II asymmetric-energy B-factory.
In this paper the studies of three different B decays to hadronic states are presented. These results are based on 1999-2003 dataset collected by the BaBar experiment at the PEP-II e+e- storage ring at the Stanford Linear Accelerator Center. The measurements are the hadronic branching fraction of B+ -> J/psi p Lambda-bar, B0 -> J/psi p p-bar, B0 -> D*+D-, and the direct CP-asymmetry in B0 -> D0(CP) K- channels.
We present preliminary measurements of the branching fractions for charmless hadronic decays of B mesons into two-body final states with kaons, pions and a phi resonance. The measurements are based on a data sample of approximately 23 million B-anti-B pairs collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC.
We report measurements of charmonium resonances (J/Psi, Psi(2S),Chi_c1) using about 25 fb^-1 of data collected by the BABAR detector around the Upsilon(4S) resonance. We present measurements of inclusive charmonium production of charmonium in B decays and from the continuum, as well as exclusive branching ratios of B mesons into charmonium final states. We present also a measurement of the B0 -> K*0 gamma branching ratio and a search for the decay B0 -> gamma gamma.
In this paper recent results in the field of B meson decays to states containing charm are presented. These analyses are based on the 1999-2003 dataset collected by the BaBar experiment at the PEP-II e+e- storage ring at the Stanford Linear Accelerator Center. Special attention is devoted to B decays to final states containing D mesons. In addition a few new results from B decays to charmonium states are reported.
We present direct CP violation measurements using the full BaBar dataset of 471 million BBbar pairs for the following charmless B decays: B0-->rho0Kstar0, B0-->f0Kstar0, B0-->rho-Kstar+ and for the Dalitz plots of B+-->K+K-K+, B+-->KsKsK+ and B0-->KsK+K-.
We report on several studies of charm baryon production and decays by the BaBar collaboration. We confirm previous observations of the $Ξ_c^{'0/+}$, $Ξ_c(2980)^+$ and $Ξ_c(3077)^+$ baryons, measure branching ratios for Cabibbo-suppressed $Λ_c^+$ decays and use baryon decays to study the properties of the light-quark baryons, $Ω^-$ and $Ξ(1690)^0$.
We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of \babar . Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics.
Using 22.7 million BBbar events recorded with the BABAR detector, the inclusive branching fractions for the production of J/psi, psi(2S) and Chi_c in B decays are presented. Combining the charmonium state with a K+-, K0, K*+-, K*0 or neutral pion, B decays are reconstructed exlusively and branching fractions are determined. A preliminary study is also presented fot the B --> eta_c K decay mode.
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 brief review of experimental results on charmonium and charmonium-like hadron spectroscopy at B-factories is presented. A special focus is put on recent results of eta_c and eta_c(2S) study, X(3872) radiative decays, omega J/psi final state study and search for charmonium production in radiative Upsilon decays.
We present a mini-review on charm spectroscopy at the BaBar experiment. We first report on the $c\bar{s}$ meson spectrum, and present precise measurements of the $D_{s1}(2536)$ meson as well as the properties of the many new states discovered since 2003 ($D_{s0}^*(2317)$, $D_{s1}(2460)$, $D_{sJ}^*(2860)$, and $D_{sJ}(2700)$ mesons). We then discuss about charmed baryons observed recently in the BaBar experiment: $Ω_c^0$ and $Ω_c^{*0}$ $css$ baryons, $Λ_c(2940)^+$ $udc$ baryon and the $Ξ_c$ $usc/dsc$ baryons.
We report preliminary results on the measurement of branching fractions of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/psi, psi(2S) and chic_c1, and the light mesons are either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.
We report results from five analyses based on data taken with the BABAR detector at the PEP-II asymmetric e+e- collider. Included are branching fraction measurements for many B-meson decays involving eta, eta', omega, phi or a0 mesons and the final state Kspi+pi-, and a full angular analysis of the decay B->phiK*0.
We report on preliminary measurements of time-dependent CP-violation asymmetries in charmless neutral B meson decays to K+K-K0 (including resonant decays phiK0 and f0K0), eta'K0, pi0K0s, K0sK0sK0s, K0sK0s, rho0K0s, omegaK0s. The results are obtained from a data sample of up to 347 million BBbar pairs produced by e+e- annihilation at the Y(4S) resonance collected with the BaBar detector at the PEP-2 asymmetric-energy B-meson Factory at SLAC.
The B factories provide a unique playground for studying the properties of conventional and exotic charmonium states. We present recent results in initial state radiation and two-photon fusion, obtained using the full data set collected by the BaBar experiment. Amongst BaBar 's harvest presented in this talk, the determination of the quantum numbers of the X(3915) resonance, a body of concording evidence pointing to JPC = 1++ for the X(3872), and updates on the family of the Y resonance to the full integrated luminosity.
We report on recent results in spectroscopy from BaBar. This includes the discovery of a new $Λ_c$ baryon, detailed studies of the $D^*_{sJ}(2317)^+$, $D_{sJ}(2460)^+$, X(3872) and Y(4260) particles and the first measurement of hadronic non-$B\bar{B}$ decays of the $Υ(4S)$ meson.
We present results of B -> vector-vector (VV) and B -> vector-axial vector (VA) decays B0 -> phi X (X = phi, rho+ or rho0), B+ -> phi K(*)+, B0 -> K*K*, B0 -> rho+b_1- and B+ -> K*0a_1+. The largest dataset used for these results is based on 465 * 10^6 Y(4S) -> BB decays, collected with the BABAR detector at the PEP-II B meson factory located at the Stanford Linear Accelerator Center (SLAC).
The BABAR experiment has completed its first year of data-taking during which 21 $fb^{-1}$ of data were accumulated. We present preliminary results on two types of charmless B decays based on this data sample. The first, $B^0 \to K^{*0}γ$, is a so-called electromagnetic penguin. And the second, $B^0 \to h^+h^{'-}$, where $h^{(')}$ can be either a pion or kaon, can come from either penguin diagrams or Cabibbo suppressed tree diagrams.
Using 8.5M B-anti-B events recorded by the BABAR detector the yield of inclusive J/psi, the branching ratios of psi(2S) and chi_C1 are presented. Combining the charmonium state with either a K+,KS, K*+ or K*0 exclusive B decays are reconstructed and their branching ratios determined. Using the fully reconstructed decays, both the B0 and B+ masses and their difference is measured. Finally the contributions of CP even and odd amplitudes in the decay B to J/psi K* are determined from an angular analysis.
We present improved measurements of the branching fractions and CP asymmetries in the two-body decays B0 --> pi0 pi0, B0 --> K0 pi0 and B0 --> K+ pi- as well as the quasi two-body B0 --> K_1(1270)+ pi- and B0 --> K_1(1400)+ pi- decays. These updated measurements are made using the complete set of BABAR data taken at the Y(4S) resonance, collected between 1999 and 2007 at the PEP-II collider at SLAC.
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.
CP-violation (CPV) and Time-reversal violation (TRV) are intimately related through the CPT theorem: if one of these discrete symmetries is violated the other one has to be violated in such a way to conserve CPT. Although CPV in the B0-B0 system has been established by the B-factories, implying indirectly TRV, there is still no direct evidence of TRV. We report on the observation of TRV in the B-meson system performed with a dataset of 468 million BB pairs produced in Y(4S) decays collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Lab…
We present several searches for charmless hadronic two-body and three-body decays of B mesons from electron-positron annihilation data collected by the BABAR detector near the Upsilon(4S) resonance. We report the preliminary branching fractions BR(B0 --> pi+pi-) = (4.1 +/- 1.0 +/- 0.7) x 10^-6, BR(B0 --> K+pi-) = (16.7 +/- 1.6 +/- 1.3) x 10^-6, BR(B0 --> rho-/+ pi+/-) = (49 +/- 13 +6 -5) x 10^-6, BR(B+ --> eta' K+) = (62 +/- 18 +/- 8) x 10^-6, and present upper limits for nine other decays.
Recent measurements in the charm sector at BaBar are reviewed. The scope of the presentation includes the observation of two new narrow mesons in the D+(s)pi0 and D+(s)pi0gamma final states as well as the measurement of D0-D0bar mixing parameters by means of two methods: using the doubly-Cabibbo-suppressed D0 decay to K+pi- and using the ratios of lifetimes extracted from samples of D0 mesons decaying to K-pi+, K-K+, and pi-pi+.
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.
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.
Following a brief introduction I report the current status of symmetry violation tests from the BaBar experiment, including recent results on the measurement of T violation, and searches for CP and T violation in mixing.
We report on the study of the decay $B^+ \to D^0(\bar{D0}) K^+$ where $D^0$ and $\bar{D0}$ decaying to $K ππ^0$, with the Atwood Dunietz and Soni (ADS) method. We measure the ratios Rads, $R^+$, $R^-$ since the processes $B^+ \to D^0 \bar{K^+}$ and $B^+ \to D^0 K^+$ are proportional to $V_{cb}$ and $V_{ub}$, respectively, are sensitive to $r_B$ and to the weak phase $γ$.
Spectroscopy results for Belle and BaBar are reported. A particular focus is put on new results of the X(3872) state with its radiative decays to $J$/$ψ$$γ$ and $ψ'$$γ$, its decay into $J$/$ψ$3$π$ and the search for production in radiative Upsilon decays. Another focus is $L$=2 mesons, in particlar a possible $D$-wave assignment to the X(3872) and the confirmation of an Upsilon $D$-wave state.
We present a preliminary measurement of the branching fraction for B to rho e nu and of the CKM matrix element |Vub| using approximately 55 million B Bbar meson pairs collected with the BABAR detector. Using isospin relations for several modes we find BF(B0 to rho- e+ nu) = (3.39+-0.44+-0.52+-0.60)x10^(-4) and |Vub| = (3.69+-0.23+-0.27+0.40-0.59)x10^(-3). The quoted errors are statistical, systematic, and theoretical, respectively. These results are obtained by using five different form-factor calculations.
The {\it BaBar} experiment has recorded the decays of more than 465$\times 10^6 B\bar{B}$ pairs since 1999, and is reaching an unprecedented precision in the measurement of hadronic B decays. The following results are presented: tests of QCD factorization with the decays $B\to χ_{c0}K^{*} $, $B\to χ_{c1,2}K^{(*)} $, and $\bar{B}^{0}\to D^{(*)0}h^{0}$, $h^0=π^0, η,\ ω, η'$, study of the decays to charmonium $B\to η_c K^{(*)},\ η_c(2S) K^{(*)}$ and $h_cK^{(*)}$, measurement of the mass difference between neutral and charged $B$'s, measurement of the "r" parameters for the extraction of the CKM a…
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.
In the Standard Model \CP violation in charm decays is expected to be very small, at the level of 0.1% or less. A significant excess of \CP violation with respect to the Standard Model predictions would be a signature of new physics. We report on recent searches for \CP violation in charm meson decays at \babar, using a data sample corresponding to an integrated luminosity of about 470 \invfb. In particular, we report on searches for \CPV in the 3-body $\Dp\to\Kp\Km\pip$ decay and for decay modes with a \KS in the final state, such as $\Dp\to\KS\Kp$, $\Ds\to\KS\Kp$, $\Ds\to\KS\pip$. A lifetime…
A first measurement of time-reversal (T) asymmetries that are not also CP asymmetries has been recently achieved by the BaBar collaboration. We analyze the measured asymmetries in the presence of direct CP violation, CPT violation, wrong strangeness decays and wrong sign semileptonic decays. We note that the commonly used S_{ψK} and C_{ψK} parameters are CP-odd, but have a T-odd CPT-even part and a T-even CPT-odd part. We introduce parameters that have well-defined transformation properties under CP, T and CPT. We identify contributions to the measured asymmetries that are T conserving. We exp…
A brief report of some recent experimental developments concerning the $X$, $Y$ and $Z$ charmoniumlike mesons states and other puzzling states from the BaBar, Belle, BESIII and CDF experiments is presented.
We present Dalitz-plot analyses of $B^+\to K^+π^-π^+$ and $B^0\to K^+π^-π^0$ using the data sample collected at the $Υ(4S)$ by the BABAR detector. We have found evidence for direct CP-violation in the decay $B^\pm\toρ^0 K^\pm$, with a CP-violation parameter ${\cal A}_{CP}={Γ_{B^+}-Γ_{B^-}\over Γ_{B^+}+Γ_{B^-}}= (+44\pm10\pm4^{+5}_{-13})%$, where $Γ_{B^\pm}$ are the decay rates. The uncertainties are statistical, systematic, and model-dependent, respectively. We also search for the suppressed decays $B^+\to K^-π^+π^+$ and $K^+K^+π^-$ and improve upper limits on the decay branching fractions.
Using 22.7M BBbar events collected with the BABAR detector at SLAC, we present preliminary measurements of the branching fractions for charmless hadronic decays of B mesons into two-body, quasi two-body and three-body final states with pions, kaons, and rho and a0 resonances. In the search for exclusive $B^0 \to π^+π^-π^0$, we measure ${\cal B}(B^0 \to ρ^{\pm}(770)π^{\mp})=(28.9\pm5.4\pm4.3) \times 10^{-6}$, together with the relative asymmetry ${\cal A}_{\rm phys} = -0.04 \pm 0.18 \pm 0.02$. We also set the upper limits on $B^0 \to ρ^0(770)π^0$, non-resonant $B^0 \to π^+π^-π^0$, $B^0 \to a_0^…
The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D0 --> l+ l- are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay Ds*(2112)+ --> Ds+ pi0 relative to the radiative decay Ds*(2112)+ --> Ds+ gamma is made. Third, the decays of DsJ*(2317)+ and DsJ(2460)+ mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Lambdac+ are examined and their branching fractions measured r…
We present preliminary results of a search for charmless two-body B decays to charged pions and kaons using data collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II storage ring. In a sample of 8.8 million produced B-anti-B pairs we measure the branching fractions B(B^0 --> pi^+pi^-) = (9.3^{+2.6}_{-2.3}^{+1.2}_{-1.4}) x 10^{-6} and B(B^0 --> K^+π^-) = (12.5^{+3.0}_{-2.6}^{+1.3}_{-1.7}) x 10^{-6}, where the first uncertainty is statistical and the second is systematic. For the decay B^0 --> K^+K^- we find no significant signal and set an upper limit of B(B^0 --> …
We report recent measurements of the CKM angle alpha using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. In addition to improved constraints on alpha from the decays B+ -> rho+ rho0, we also present preliminary results of neutral and charged B meson decays to K_1(1270) pi and K_1(1400) pi and its impact on the estimate for the CKM angle alpha based on time-dependent analysis of CP-violating asymmetries in B0 -> a_1(1260) pi. Moreover we report the first observation of the decay B -> a_1(1260)+ a_1(1260)-; this mo…
The search for rare B decays and direct CP violation at BABAR is described. The following measurements (based on integrated luminosities ranging from 56.4 to 81.9fb-1) are summarized: the inclusive branching fractions and direct CP asymmetries of B+ to h+h-h+ (h=pi, K), the exclusive branching fractions of B+ to K+pi-pi+ (where significant signals are observed in the B+ to K*0(892)pi+, B+ to f0(980)K+, B+ to chic0 K+, B+ to Dbar0 pi+ and B^+ to higher K*0 pi+ channels), the branching fractions of B+ to rho0rho+ and B+ to rho0 K*+, and finally, the branching fractions, the longitudinal componen…
We present preliminary results of several searches for rare charmless hadronic decays of the B meson using data collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II storage ring. We search for the decays h^+h^-, h^+h^-h^+, h^+h^-pi^0, X^0h^+, and X^0 K_S^0, where h = pi or K, and X^0 = eta^prime or omega. In a sample of 8.8 million B-anti-B decays we measure the branching fractions: BF(B^0 --> pi^+pi^-) = (9.3^{+2.6}_{-2.3}^{+1.2}_{-1.4}) x 10^{-6}, BF(B^0 --> K^+pi^-) = (12.5^{+3.0}_{-2.6}^{+1.3}_{-1.7}) x 10^{-6}, BF(B^0 --> rho^-pi^+) = (49 +/- 13^{+6}_{-5}) x …
Recent results obtained using the data sample collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider and the Babar detector at the PEP-II asymmetric-energy e^+ e^- collider are discussed. Measurements of several charmless and charmed baryonic B decay branching fractions are reported, and some behaviors and mechanisms are discussed.