We study the e+e- --> Lambda anti-Lambda gamma, Lambda anti-Sigma0 gamma, Sigma0 anti-Sigma0 gamma processes using 230 fb-1 of integrated luminosity collected by the BABAR detector at e+e- ...center-of-mass energy of 10.58 GeV. From the analysis of the baryon-antibaryon mass spectra the cross sections for e+e- --> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 are measured in the dibaryon mass range from threshold up to 3 GeV/c^2. The ratio of electric and magnetic form factors, |G_E/G_M|, is measured for e+e- --> Lambda anti-Lambda, and limits on the relative phase between Lambda form factors are obtained. We also measure the J/psi --> Lambda anti-Lambda, Sigma0 anti-Sigma0 and psi(2S) --> Lambda anti-Lambda branching fractions.
With a sample of 232x10^6 Upsilon(4S)->BBbar events collected with the BaBar detector, we study the decays of B mesons to ppbarh final states, where h=pi+,Ks,K*0 or K*+. We report evidence for the ...B->ppbarK*0 decay, with a branching fraction (1.5+/-0.5(stat)+/-0.4(syst))x10^-6, and for the B+->eta_cK*+ decay, with the branching fraction of Br(B+->eta_cK*+)xBr(eta_c->ppbar)=(1.57^{+0.56}_{-0.45}(stat)^{+0.46}_{-0.36}(syst))x10^-6, and provide improved measurements of the branching fractions of the other modes of this type. We also report the measurements of the charge asymmetry consistent with zero in the B+->ppbarpi+, B0->ppbarK*0 and B+->ppbarK*+ modes. No evidence is found for the pentaquark candidate Theta+ in the mass range 1.52 to 1.55 GeV/c^2, decaying into pKs, or the glueball candidate fJ(2220) in the mass range 2.2
Motivated by the polarization anomaly in the B->phi(1020)K*(892) decay, we extend our search for other K* final states in the decay B0->phi(1020)K^*0 with the K*0->K+pi- invariant mass above 1.6 GeV. ...The final states considered include the K*(1680)0, K3*(1780)0, K4*(2045)0, and a Kpi spin-zero nonresonant component. We also search for B0->phiDbar0 decay with the same final state. The analysis is based on a sample of about 384 million BBbar pairs recorded with the BABAR detector. We place upper limits on the branching fractions BR(B0->phiK*(1680)0)<3.5*10^-6, BR(B0->phiK3*(1780)0)<2.7*10^-6, BR(B0->phiK4*(2045)0)<15.3*10^-6, and BR(B0->phiDbar0)<11.7*10^-6 at 90% C.L. The nonresonant contribution is consistent with the measurements in the lower invariant mass range.
We present measurements of the time-dependent CP-violating asymmetries in B0 --> K0S K0S K0S decays based on 384 million Y(4S) decays collected with the BABAR detector at the PEP-II asymmetric-energy ...B Factory at SLAC. We obtain the CP asymmetry parameters C = 0.02 +/- 0.21 +/- 0.05 and S = -0.71 +/- 0.24 +/- 0.04, where the first uncertainties are statistical and the second systematic. These results are consistent with standard model expectations.
We have searched for $D^0 - \bar{D}^0$ mixing in $D^{*+} \to \pi^+ D^0$ decays with $D^0 \to K^{(*)} e \nu$ in a sample of $e^+ e^- \to {c\bar c}$ events produced near 10.58 GeV. The charge of the ...slow pion from charged $D^*$ decay tags the charm flavor at production, and it is required to be consistent with the flavor of a fully reconstructed second charm decay in the same event. We observe 3 mixed candidates compared to 2.85 background events expected from simulation. We ascribe a 50% systematic uncertainty to this expected background rate. We find a central value for the mixing rate of $0.4 \times 10^{-4}$. Using a frequentist method, we set corresponding 68% and 90% confidence intervals at $(-5.6, 7.4) \times 10^{-4}$ and $(-13, 12) \times 10^{-4}$, respectively.
We report on a search for the process B+ -> Kbar*0(892) K+ using 232 10^6 Upsilon(4S) -> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. From a ...signal yield of 25 +/- 13 stat +/- 7 syst B+ -> Kbar*0(892) (-> K- pi+) K+ events, we place an upper limit on the branching fraction BF(B+ -> Kbar*0(892) K+) of 1.1 10^-6, at the 90% confidence level.
We perform the first three-dimensional measurement of the amplitudes of $B\to \psi(2S) K^*$ and $B\to \chi_{c1} K^*$ decays and update our previous measurement for $B\to J/\psi K^*$. We use a data ...sample collected with the BaBar detector at the PEP2 storage ring, corresponding to 232 million $B\bar B$ pairs. The longitudinal polarization of decays involving a $J^{PC}=1^{++}$ $\chi_{c1}$ meson is found to be larger than that with a $1^{--}$ $J/\psi$ or $\psi(2S)$ meson. No direct {\it CP}-violating charge asymmetry is observed.
We present measurements of the branching fractions for B0 meson decays to eta'K0 and omegaK0, and of the branching fractions and CP-violation charge asymmetries for B+ meson decays to etapi+, etaK+, ...eta'pi+, eta'K+, omegapi+, and omegaK+. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 383 million BBbar pairs produced in e+e- annihilation. The measurements agree with previous results; we find no evidence for direct CP violation.
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.
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