We report a measurement of the branching fractions of B{yields}D**l{sup -}{nu}{sub l} decays based on 417 fb{sup -1} of data collected at the {upsilon}(4S) resonance with the BABAR detector at the ...PEP-II e{sup +}e{sup -} storage rings. Events are selected by fully reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D{sup (*)}{pi})-m(D{sup (*)}) is performed to extract the signal yields of the different D** states. We observe the B{yields}D**l{sup -}{nu}{sub l} decay modes corresponding to the four D** states predicted by heavy quark symmetry with a significance greater than 5 standard deviations including systematic uncertainties.
We report the observation of the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ based on $342 \mathrm {\,fb}^{-1}}$ of data collected at the $\Y4S$ resonance with the BABAR ...detector at the PEP-II $e^{+}e^{-}$ storage rings at SLAC. A simultaneous fit to three $D^{+}_{s}$ decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ with a significance greater than five standard deviations (including systematic uncertainties) and measure its branching fraction to be $\BR(B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}) = 6.13^{+1.04}_{-1.03}(\mathrm{stat.})\pm0.43(\mathrm{syst.}) \pm 0.51(\BR(D_{s}))\times10^{-4}$, where the last error reflects the limited knowledge of the $D_{s}$ branching fractions.
We have performed a search for the {eta}{sub b}(1S) meson in the radiative decay of the {Upsilon}(2S) resonance using a sample of 91.6 million {Upsilon}(2S) events recorded with the BABAR detector at ...the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E{sub {gamma}} = 610.5{sub -4.3}{sup +4.5}(stat) {+-} 1.8(syst) MeV, corresponding to an {eta}{sub b}(1S) mass of 9392.9{sub -4.8}{sup +4.6}(stat) {+-} 1.9(syst) MeV/c{sup 2}. The branching fraction for the decay {Upsilon}(2S) {yields} {gamma}{eta}{sub b}(1S) is determined to be (4.2{sub -1.0}{sup +1.1}(stat) {+-} 0.9(syst)) x 10{sup -4}. The ratio {Beta}({Upsilon}(2S) {yields} {gamma}{eta}{sub b}(1S))/{Beta}({Upsilon}(3S) {yields} {gamma}{eta}{sub b}(1S)) = 0.89{sub -0.23}{sup +0.25}(stat){sub -0.16}{sup +0.12}(syst) is consistent with the ratio expected for magnetic dipole transitions to the {eta}{sub b}(1S) meson.
We present the results of searches for B decays to charmless final states involving {phi}, f{sub 0}(980), and charged or neutral {rho} mesons. The data sample corresponds to 384x10{sup 6} BB pairs ...collected with the BABAR detector operating at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. We find no significant signals and determine the following 90% confidence level upper limits on the branching fractions, including systematic uncertainties: B(B{sup 0}{yields}{phi}{phi})<2.0x10{sup -7}, B(B{sup +}{yields}{phi}{rho}{sup +})<30x10{sup -7}, B(B{sup 0}{yields}{phi}{rho}{sup 0})<3.3x10{sup -7}, BB{sup 0}{yields}{phi}f{sub 0}(980)xBf{sub 0}(980){yields}{pi}{sup +}{pi}{sup -}<3.8x10{sup -7}, and BB{sup 0}{yields}f{sub 0}(980)f{sub 0}(980)xBf{sub 0}(980){yields}{pi}{sup +}{pi}{sup -}xBf{sub 0}(980){yields}K{sup +}K{sup -}<2.3x10{sup -7}.
With the full BABAR data sample of 465x10{sup 6} BB pairs, we observe the decays B{sup {+-}}{yields}{phi}K{sub 1}(1270){sup {+-}} and B{sup {+-}}{yields}{phi}K{sub 2}*(1430){sup {+-}}. We measure the ...branching fractions (6.1{+-}1.6{+-}1.1)x10{sup -6} and (8.4{+-}1.8{+-}1.0)x10{sup -6} and the fractions of longitudinal polarization 0.46{sub -0.13-0.07}{sup +0.12+0.06} and 0.80{sub -0.10}{sup +0.09}{+-}0.03, respectively. We also report on the B{sup {+-}}{yields}{phi}K{sub 0}*(1430){sup {+-}} decay branching fraction of (7.0{+-}1.3{+-}0.9)x10{sup -6} and several parameters sensitive to CP violation and interference in the above three decays. Upper limits are placed on the B{sup {+-}} decay rates to final states with {phi} and K{sub 1}(1400){sup {+-}}, K*(1410){sup {+-}}, K{sub 2}(1770){sup {+-}}, or K{sub 2}(1820){sup {+-}}. Understanding the observed polarization pattern requires amplitude contributions from an uncertain source.
We perform a measurement of the CP asymmetry in b{yields}s{gamma} decays using a sample of 383x10{sup 6} BB events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We ...reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X{sub s} containing an s quark. We measure the CP asymmetry to be -0.011{+-}0.030(stat){+-}0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c{sup 2}.
We report measurements of branching fractions for the decays B{yields}Pl{nu}{sub l}, where P are the pseudoscalar charmless mesons {pi}{sup -}, {pi}{sup 0}, {eta} and {eta}{sup '}, based on 348 ...fb{sup -1} of data collected with the BABAR detector, using B{sup 0} and B{sup +} mesons found in the recoil of a second B meson decaying as B{yields}D{sup (*)}l{nu}{sub l}. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B{sup 0}{yields}{pi}{sup -}l{sup +}{nu}{sub l})=(1.54{+-}0.17{sub (stat)}{+-}0.09{sub (syst)})x10{sup -=} 4; we find 3.2{sigma} evidence of the decay B{sup +}{yields}{eta}l{sup +}{nu}{sub l} and measure its branching fraction to be (0.64{+-}0.20{sub (stat)}{+-}0.03{sub (syst)})x10{sup -4}, and determine B(B{sup +}{yields}{eta}{sup '}l{sup +}{nu}{sub l})<0.47x10{sup -4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a variety of form factor calculation, we obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| in ranging from 3.6x10{sup -3} to 4.1x10{sup -3}.
We report the results of a search for the bottomonium ground state {eta}{sub b}(1S) in the photon energy spectrum with a sample of (109{+-}1) million of {upsilon}(3S) recorded at the {upsilon}(3S) ...energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at E{sub {gamma}}=921.2{sub -2.8}{sup +2.1}(stat){+-}2.4(syst) MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition {upsilon}(3S){yields}{gamma}{eta}{sub b}(1S). This photon energy corresponds to an {eta}{sub b}(1S) mass of 9388.9{sub -2.3}{sup +3.1}(stat){+-}2.7(syst) MeV/c{sup 2}. The hyperfine {upsilon}(1S)-{eta}{sub b}(1S) mass splitting is 71.4{sub -3.1}{sup +2.3}(stat){+-}2.7(syst) MeV/c{sup 2}. The branching fraction for this radiative {upsilon}(3S) decay is estimated to be 4.8{+-}0.5(stat){+-}1.2(syst)x10{sup -4}.
Using 383x10{sup 6} BB pairs from the BABAR data sample, we report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance ...decaying to KK* or {eta}{pi}{pi} final states with mass in the range (1.2-1.8) GeV/c{sup 2}. We observe a significant enhancement at the low KK* invariant mass which is interpreted as B{sup +}{yields}{eta}(1475)K{sup +}, find evidence for the decay B{sup +}{yields}{eta}(1295)K{sup +}, and place upper limits on the decays B{sup +}{yields}{eta}(1405)K{sup +}, B{sup +}{yields}f{sub 1}(1285)K{sup +}, B{sup +}{yields}f{sub 1}(1420)K{sup +}, and B{sup +}{yields}{phi}(1680)K{sup +}.
We present measurements of the branching fraction and time-dependent CP asymmetries in B{sup 0}{yields}J/{psi}{pi}{sup 0} decays based on 466x10{sup 6} {upsilon}(4S){yields}BB events collected with ...the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We measure the CP asymmetry parameters S=-1.23{+-}0.21(stat){+-}0.04(syst) and C=-0.20{+-}0.19(stat){+-}0.03(syst), where the measured value of (S, C) is 4.0 standard deviations from (0, 0) including systematic uncertainties. The branching fraction is determined to be B(B{sup 0}{yields}J/{psi}{pi}{sup 0})=1.69{+-}0.14(stat){+-}0.07(syst)x10{sup -5}.
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