Branching Fraction and CP Asymmetry Measurements in Inclusive B -> Xs l+l- and B -> Xs gamma Decays from BABAR

We present an update on total and partial branching fractions and on CP asymmetries in the semi-inclusive decay B -> Xs l+l-. Further, we summarize our results on branching fractions and CP asymmetries for semi-inclusive and fully-inclusive B -> Xs gamma decays. We present the first result on the CP asymmetry difference of charged and neutral B -> Xs gamma$ decays yielding the first constraint on the ratio of Wilson coefficients Im (C8/C7).

Measurement of the $D^0 to pi^- e^+ u_e$ differential decay branching fraction as a function of $q^2$ and study of form factor parameterizations

Based on a sample of 500 million $e^+e^- to cbar c$ events recorded by the BaBar detector at c.m. energies of close to 10.6 GeV, we report on a study of the decay $D^0 to pi^- e^+ u_e$. We measure the ratio of branching fractions $R_D = {cal B}(D^0 to pi^- e^+ u_e)/{cal B}(D^0 to K^- pi^+) = 0.0713 pm 0.0017_{stat.} pm 0.0024_{syst.}$, and use the present world average for ${cal B}(D^0 to K^- pi^+)$ to obtain ${cal B}(D^0 to pi^- e^+ u_e) = (2.770 pm 0.068_{{rm stat.}} pm 0.092_{{rm syst.}} pm 0.037_{{rm ext.}})times 10^{-3}$ where the third error accounts for the uncertainty on the branching fraction for the reference channel. The measured dependence of the differential branching fraction on $q^2$, the four-momentum transfer squared between the $D$ and the $pi$ meson, is compared to various theoretical predictions for the hadronic form factor, $f_{+,D}^{pi}(q^2)$, and the normalization $|V_{cd}| times f_{+,D}^{pi}(q^2=0)=0.1374pm0.0038_{{rm stat.}} pm0.0022_{{rm syst.}} pm0.0009_{{rm ext.}}$ is extracted from a fit to data. Using the most recent LQCD prediction of $f_{+,D}^{pi}(q^2=0)=0.666 pm 0.029$, we obtain $|V_{cd}|=0.206 pm 0.007_{rm exp.} pm 0.009_{rm LQCD}$. Assuming instead, $|V_{cd}|=|V_{us}|=0.2252 pm 0.0009$, we obtain $f_{+,D}^{pi}(q^2=0)=0.610 pm 0.020_{rm exp.} pm 0.005_{rm ext.}$. The $q^2$ dependence of $f_{+,D}^{pi}(q^2)$ is compared to a variety of multi-pole parameterizations. This information is applied to $B^0 to pi^- e^+ u_e$ decays and, combined with an earlier $B^0 to pi^- e^+ u_e$ measurement by BaBar, is used to derive estimates of $|V_{ub}|$.

Measurements of Direct CP Asymmetries in B to X_s gamma decays using Sum of Exclusive Decays

We measure the direct CP violation asymmetry, A_CP, in B to X_s gamma and the isospin difference of the asymmetry, Delta A_CP, using 429 fb^-1 of data collected at Upsilon(4S) resonance with the BaBar detector at the PEP-II asymmetric-energy e+e- storage rings operating at the SLAC National Accelerator Laboratory. B mesons are reconstructed from 10 charged B final states and 6 neutral B final states. We find A_CP = +(1.7 +- 1.9 +- 1.0)%, which is in agreement with the Standard Model prediction and provides an improvement on the world average. Moreover, we report the first measurement of the difference between A_CP for charged and neutral decay modes, Delta A_CP = +(5.0 +- 3.9 +- 1.5)%. Using the value of Delta A_CP, we also provide 68% and 90% confidence intervals on the imaginary part of the ratio of the Wilson coefficients corresponding to the chromo-magnetic dipole and the electromagnetic dipole transitions.

Cross sections for the reactions $e^+ e^-to K_S^0 K_L^0$, $K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ from events with initial-state radiation

We study the processes $e^+ e^-to K_S^0 K_L^0 gamma$, $K_S^0 K_L^0 pi^+pi^-gamma$, $K_S^0 K_S^0 pi^+pi^-gamma$, and $K_S^0 K_S^0 K^+K^-gamma$, where the photon is radiated from the initial state, providing cross section measurements for the hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ of data collected with the BaBar detector at SLAC. We observe the $phi(1020)$ resonance in the $K_S^0 K_L^0$ final state and measure the product of its electronic width and branching fraction with about 3% uncertainty. We present a measurement of the $e^+ e^-to K_S^0 K_L^0 $ cross section in the energy range from 1.06 to 2.2 GeV and observe the production of a resonance at 1.67 GeV. We present the first measurements of the $e^+ e^-to K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ cross sections, and study the intermediate resonance structures. We obtain the first observations of jpsi decay to the $K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ final states.

Evidence for the decay B0 --> omega omega and search for B0 --> omega phi

We describe searches for B meson decays to the charmless vector-vector final states omega omega and omega phi with 471 x 10^6 B Bbar pairs produced in e+ e- annihilation at sqrt(s) = 10.58 GeV using the BABAR detector at the PEP-II collider at the SLAC National Accelerator Laboratory. We measure the branching fraction B(B0 --> omega omega) = (1.2 +- 0.3 +0.3-0.2) x 10^-6, where the first uncertainty is statistical and the second is systematic, corresponding to a significance of 4.4 standard deviations. We also determine the upper limit B(B0 --> omega phi) < 0.7 x 10^-6 at 90% confidence level. These measurements provide the first evidence for the decay B0 --> omega omega, and an improvement of the upper limit for the decay B0 --> omega phi.

Study of the decay $bar{B}^{0}rightarrowLambda_{c}^{+}bar{p}pi^{+}pi^{-}$ and its intermediate states

We study the decay $bar{B}^{0}rightarrowLambda_{c}^{+}bar{p}pi^{+}pi^{-}$, reconstructing the Lambda_{c}^{+} baryon in the $p K^{-}pi^{+}$ mode, using a data sample of $467times 10^{6}$ $Bbar{B}$ pairs collected with the BaBar detector at the PEP-2 storage rings at SLAC. We measure branching fractions for decays with intermediate $Sigma_{c}$ baryons to be ${cal B}[bar{B}^{0}rightarrowSigma_{c}(2455)^{++}bar{p}pi^{-}]=(21.3 pm 1.0 pm 1.0 pm 5.5) times 10^{-5}$, ${cal B}[bar{B}^{0}rightarrowSigma_{c}(2520)^{++}bar{p}pi^{-}]=(11.5pm 1.0 pm 0.5 pm 3.0)times 10^{-5}$, ${cal B}[bar{B}^{0}rightarrowSigma_{c}(2455)^{0}bar{p}pi^{+}]=(9.1 pm 0.7 pm 0.4 pm 2.4)times10^{-5}$, and ${cal B}[bar{B}^{0}rightarrowSigma_{c}(2520)^{0}bar{p}pi^{+}]= (2.2 pm 0.7 pm 0.1pm 0.6) times 10^{-5}$, where the uncertainties are statistical, systematic, and due to the uncertainty on the $Lambda_{c}^{+}rightarrowprotonKmpi^{+}$ branching fraction, respectively. For decays without $Sigma_{c}(2455)$ or $Sigma_{c}(2520)$ resonances, we measure ${cal B}[bar{B}^{0}rightarrowLambda_{c}^{+}bar{p}pi^{+}pi^{-}]_{mathrm{non-Sigma_{c}}}=(79 pm 4 pm 4 pm 20)times10^{-5}$. The total branching fraction is determined to be ${cal B}[bar{B}^{0}rightarrowLambda_{c}^{+}bar{p}pi^{+}pi^{-}]_{mathrm{total}}=(123 pm 5 pm 7 pm 32)times10^{-5}$. We examine multibody mass combinations in the resonant three-particle $Sigma_{c}bar{p}pi$ final states and in the four-particle $Lambda_{c}^{+}bar{p}pi^{+}pi^{-}$ final state, and observe different characteristics for the $bar{p}pi$ combination in neutral versus doubly-charged $Sigma_{c}$ decays.

Charmonium-like States at BaBar

We present recent results on charmonium and charmonium-like states from the BaBar B-factory located at the PEP-II asymmetric energy $e^{+}e^{-}$ storage ring at the SLAC National Accelerator Laboratory.

Study of the reaction e^{+}e^{-}->psi(2S)pi^{-}pi^{-} via initial state radiation at BaBar

We study the process $e^+e^-topsi(2S)pi^{+}pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies at and near the $Upsilon(mathrm{nS})$ (n = 2, 3, 4) resonances and correspond to an integrated luminosity of 520$fb^{-}$. We investigate the $psi(2S)pi^{+}pi^{-}$ mass distribution from 3.95 to 5.95 $GeV/c^{2}$, and measure the center-of-mass energy dependence of the associated $e^+e^-to psi(2S)pi^{+}pi^{-}$ cross section. The mass distribution exhibits evidence of two resonant structures. A fit to the $psi(2S)pi^{+}pi^{-}$ mass distribution corresponding to the decay mode $psi(2S)to J/psi pi^{+}pi^{-}$ yields a mass value of $4340 pm16$ (stat) $pm 9$ (syst) ${mathrm {MeV/c^{2}}}and a width of $94 pm 32$ (stat) $pm 13$ (syst) MeV for the first resonance, and for the second a mass value of $4669 pm 21$ (stat) $pm 3$ (syst) ${mathrm {MeV/c^{2}}}$ and a width of $104 pm 48$ (stat) $pm 10$ (syst) MeV. In addition, we show the $pi^{+}pi^{-}$ mass distributions for these resonant regions.

Results on Charmonium-like States at BaBar

We present recent results on charmonium and charmonium-like states from the BaBar B-factory located at the PEP-II asymmetric energy $e^{+}e^{-}$ storage ring at the SLAC National Accelerator Laboratory.

Observation of Time Reversal Violation in the B0 Meson System

Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time reversal violation. The decays of entangled neutral B mesons into definite flavor states ($B^0$ or $bar{B}^0$), and $J/psi K_S^0$ or $cbar{c} K_S^0$ final states (referred to as $B_+$ or $B_-$), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, $bar{B}^0 rightarrow B_-$ and $B_- rightarrow bar{B}^0$, as a function of the time difference between the two B decays. Using 468 million $Bbar{B}$ pairs produced in $Upsilon(4S)$ decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding $Delta S_T^+ = -1.37 pm 0.14 (stat.) pm 0.06 (syst.)$ and $Delta S_T^- = 1.17 pm 0.18 (stat.) pm 0.11 (syst.)$. These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.