A. J. Hart

Measurements of moments of the hadronic mass distribution in semileptonic B decays

B. Aubert, R. Barate, D. Boutigny, F. Couderc, J.-M. Gaillard, A. Hicheur, Y. Karyotakis, J. P. Lees, V. Tisserand, A. Zghiche, A. Palano, A. Pompili, J. C. Chen, N. D. Qi, G. Rong, P. Wang, Y. S. Zhu, G. Eigen, I. Ofte, B. Stugu, G. S. Abrams, A. W. Borgland, A. B. Breon, D. N. Brown, J. Button-Shafer, R. N. Cahn, E. Charles, C. T. Day, M. S. Gill, A. V. Gritsan, Y. Groysman, R. G. Jacobsen, R. W. Kadel, J. Kadyk, L. T. Kerth, Yu. G. Kolomensky, G. Kukartsev, C. LeClerc, M. E. Levi, G. Lynch, L. M. Mir, P. J. Oddone, T. J. Orimoto, M. Pripstein, N. A. Roe, M. T. Ronan, V. G. Shelkov, A. V. Telnov, W. A. Wenzel, K. Ford, T. J. Harrison, C. M. Hawkes, S. E. Morgan, A. T. Watson, N. K. Watson, M. Fritsch, K. Goetzen, T. Held, H. Koch, B. Lewandowski, M. Pelizaeus, K. Peters, H. Schmuecker, M. Steinke, J. T. Boyd, N. Chevalier, W. N. Cottingham, M. P. Kelly, T. E. Latham, C. Mackay, F. F. Wilson, K. Abe, T. Cuhadar-Donszelmann, C. Hearty, T. S. Mattison, J. A. McKenna, D. Thiessen, P. Kyberd, A. K. McKemey, L. Teodorescu, V. E. Blinov, A. D. Bukin, V. B. Golubev, V. N. Ivanchenko, E. A. Kravchenko, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, E. P. Solodov, A. N. Yushkov, D. Best, M. Bruinsma, M. Chao, I. Eschrich, D. Kirkby, A. J. Lankford, M. Mandelkern, R. K. Mommsen, W. Roethel, D. P. Stoker, C. Buchanan, B. L. Hartfiel, J. W. Gary, J. Layter, B. C. Shen, K. Wang, D. del Re, H. K. Hadavand, E. J. Hill, D. B. MacFarlane, H. P. Paar, Sh. Rahatlou, V. Sharma, J. W. Berryhill, C. Campagnari, B. Dahmes, S. L. Levy, O. Long, A. Lu, M. A. Mazur, J. D. Richman, W. Verkerke, T. W. Beck, J. Beringer, A. M. Eisner, C. A. Heusch, W. S. Lockman, T. Schalk, R. E. Schmitz, B. A. Schumm, A. Seiden, P. Spradlin, W. Walkowiak, D. C. Williams, M. G. Wilson, J. Albert, E. Chen, G. P. Dubois-Felsmann, A. Dvoretskii, R. J. Erwin, D. G. Hitlin, I. Narsky, T. Piatenko, F. C. Porter, A. Ryd, A. Samuel, S. Yang, S. Jayatilleke, G. Mancinelli, B. T. Meadows, M. D. Sokoloff, T. Abe, F. Blanc, P. Bloom, S. Chen, P. J. Clark, W. T. Ford, U. Nauenberg, A. Olivas, P. Rankin, J. Roy, J. G. Smith, W. C. van Hoek, L. Zhang, J. L. Harton, T. Hu, A. Soffer, W. H. Toki, R. J. Wilson, J. Zhang, D. Altenburg, T. Brandt, J. Brose, T. Colberg, M. Dickopp, E. Feltresi, A. Hauke, H. M. Lacker, E. Maly, R. Müller-Pfefferkorn, R. Nogowski, S. Otto, J. Schubert, K. R. Schubert, R. Schwierz, B. Spaan, D. Bernard, G. R. Bonneaud, F. Brochard, P. Grenier, Ch. Thiebaux, G. Vasileiadis, M. Verderi, D. J. Bard, A. Khan, D. Lavin, F. Muheim, S. Playfer, M. Andreotti, V. Azzolini, D. Bettoni, C. Bozzi, R. Calabrese, G. Cibinetto, E. Luppi, M. Negrini, L. Piemontese, A. Sarti, E. Treadwell, R. Baldini-Ferroli, A. Calcaterra, R. de Sangro, G. Finocchiaro, P. Patteri, M. Piccolo, A. Zallo, A. Buzzo, R. Capra, R. Contri, G. Crosetti, M. Lo Vetere, M. Macri, M. R. Monge, S. Passaggio, C. Patrignani, E. Robutti, A. Santroni, S. Tosi, S. Bailey, M. Morii, E. Won, R. S. Dubitzky, U. Langenegger, W. Bhimji, D. A. Bowerman, P. D. Dauncey, U. Egede, J. R. Gaillard, G. W. Morton, J. A. Nash, G. P. Taylor, G. J. Grenier, S.-J. Lee, U. Mallik, J. Cochran, H. B. Crawley, J. Lamsa, W. T. Meyer, S. Prell, E. I. Rosenberg, J. Yi, M. Davier, G. Grosdidier, A. Höcker, S. Laplace, F. Le Diberder, V. Lepeltier, A. M. Lutz, T. C. Petersen, S. Plaszczynski, M. H. Schune, L. Tantot, G. Wormser, V. Brigljević, C. H. Cheng, D. J. Lange, M. C. Simani, D. M. Wright, A. J. Bevan, J. P. Coleman, J. R. Fry, E. Gabathuler, R. Gamet, M. Kay, R. J. Parry, D. J. Payne, R. J. Sloane, C. Touramanis, J. J. Back, P. F. Harrison, G. B. Mohanty, C. L. Brown, G. Cowan, R. L. Flack, H. U. Flaecher, S. George, M. G. Green, A. Kurup, C. E. Marker, T. R. McMahon, S. Ricciardi, F. Salvatore, G. Vaitsas, M. A. Winter, D. Brown, C. L. Davis, J. Allison, N. R. Barlow, R. J. Barlow, P. A. Hart, M. C. Hodgkinson, G. D. Lafferty, A. J. Lyon, J. C. Williams, A. Farbin, W. D. Hulsbergen, A. Jawahery, D. Kovalskyi, C. K. Lae, V. Lillard, D. A. Roberts, G. Blaylock, C. Dallapiccola, K. T. Flood, S. S. Hertzbach, R. Kofler, V. B. Koptchev, T. B. Moore, S. Saremi, H. Staengle, S. Willocq, R. Cowan, G. Sciolla, F. Taylor, R. K. Yamamoto, D. J. J. Mangeol,

Measurement of the branching fraction of Υ(4S)→B0B̄0

We report the first measurement of the branching fraction f00 for Υ(4S)→B0B 0. The data sample consists of 81.7  fb-1 collected at the Υ(4S) resonance with the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- storage ring. Using partial reconstruction of the decay B 0→D*+l-ν l in which only the charged lepton and the soft pion from the decay D*+→D0π+ are reconstructed, we obtain f00=0.487±0.010(stat)±0.008(syst). Our result does not depend on the branching fractions of B 0→D*+l-ν l and D*+→D0π+ decays, on the ratio of the charged and neutral B meson lifetimes, nor on the assumption of isospin symmetry.

Measurement of the B → nlv branching fraction and determination of

We report a measurement of the B ->pi center dot nu branching fraction based on 211 fb(-1) of data collected with the BABAR detector. We use samples of B-0 and B+ mesons tagged by a second B meson reconstructed in a semileptonic or hadronic decay and combine the results assuming isospin symmetry to obtain B(B-0 ->pi(-)center dot(+)nu)=(1.33 +/- 0.17(stat)+/- 0.11(syst))x10(-4). We determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar by combining the partial branching fractions measured in ranges of the momentum transfer squared and theoretical calculations of the form factor. Using a recent lattice QCD calculation, we find vertical bar V-ub vertical bar=(4.5 +/- 0.5(stat)+/- 0.3(syst)0.7/0.5(FF))x10(-3), where the last error is due to the normalization of the form factor.

Search for D0-D̄0 mixing and branching-ratio measurement in the decay D0→K+π-π0 - eScholarship

We analyze 230.4 fb;{-1} of data collected with the BABAR detector at the PEP-II e;{+}e;{-} collider at SLAC to search for evidence of D0-D[over ];{0} mixing using regions of phase space in the decay D;{0}-->K;{+}pi;{-}pi;{0}. We measure the time-integrated mixing rate R_{M}=(0.023_{-0.014};{+0.018}(stat.)+/-0.004(syst.))%, and R_{M}<0.054% at the 95% confidence level, assuming CP invariance. The data are consistent with no mixing at the 4.5% confidence level. We also measure the branching ratio for D;{0}-->K;{+}pi;{-}pi;{0} relative to D;{0}-->K;{-}pi;{+}pi;{0} to be (0.214+/-0.008(stat.)+/-0.008(syst.))%.

Observation of the exclusive reaction e+e-→η at s=10.58GeV - eScholarship

We report the observation of e+e-→η near s=10.58GeV with 6.5σ significance in the K+K-γγ final state in a data sample of 224fb-1 collected by the BABAR experiment at the PEP-II e+e- storage rings. We measure the restricted radiation-corrected cross section to be σ(e+e-→η)=2.1±0.4(stat)±0.1(syst)fb within the range |cosθ*|<0.8, where θ* is the center-of-mass polar angle of the meson. The meson is required to be in the invariant mass range of 1.008<m<1.035GeV/c2. The radiation-corrected cross section in the full cosθ* range is extrapolated to be 2.9±0.5(stat) ±0.1(syst)fb.

Search for factorization-suppressed B→χcK(*) decays

We search for the factorization-suppressed decays B→χc0K(*) and B→χc2K(*), with χc0 and χc2 decaying into J/ψγ, using a sample of 124×106 BB events collected with the BABAR detector at the PEP-II storage ring of the Stanford Linear Accelerator Center. We find no significant signal and set upper bounds for the branching fractions.

Improved measurement of the Cabibbo-Kobayashi-Maskawa angle α using B0(B̄)→ρ+ρ- decays

We present results from an analysis of B(0)B(0)--> rho(+)rho(-) using 232 x 10(6) Gamma (4S) --> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We measure the longitudinal polarization fraction f(L) = 0.978 +/- 0.014(stat) + 0.021 / -0.029(syst) and the CP-violating parameters S(L)= -0.33 +/- 0.24(stat) + 0.08 / -0.14(syst) and C(L)= -0.03 +/- 0.18(stat) +/- 0.09(syst). Using an isospin analysis of B --> rhorho decays, we determine the unitarity triangle parameter alpha. The solution compatible with the standard model is alpha = (100 +/- 13) degrees.

Search for decays of B0→e+e-, B0→μ+μ-, B0→e± μ

We present a search for the decays B0->e+e-, B0->mu+mu-, and B0->e+- mu-+ in data collected at the Y(4S) resonance with the Babar detector at the SLAC B Factory. Using a data set of 111 fb^-1, we find no evidence for a signal in any of the three channels investigated and set the following branching fraction upper limits at the 90% confidence level: B(B0->e+e-) mu+mu-) e+-mu-+) < 18 x 10^-8.

Study of B→π ν and B→ρ ν decays and determination of

We present an analysis of exclusive charmless semileptonic B-meson decays based on 83×106 BB pairs recorded with the BABAR detector at the Υ(4S) resonance. Using isospin symmetry, we measure branching fractions B(B0→π- +ν)=(1.38±0.10±0.16±0.08)×10-4 and B(B0→ρ- +ν)=(2.14±0.21±0.48±0.28)×10-4, where the errors are statistical, experimental systematic, and due to form-factor shape uncertainties. We compare the measured distribution in q2, the momentum-transfer squared, with theoretical predictions for the form factors from lattice QCD and light-cone sum rules, and extract the Cabibbo-Kobayashi- Maskawa (CKM) matrix element |Vub|=(3.82±0.14±0.22±0.11-0. 52+0.88)×10-3 from B→π ν, where the fourth error reflects the uncertainty of the form-factor normalization.

Measurement of the B̄ 0 → D * + ℓ - ν̄ ℓ decay rate and |V cb |

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V(cb)vertical bar based on a sample of about 53 700 (B) over bar (0) -> D*(+)l(-)(nu) over bar (l) decays observed by the BABAR detector. We obtain the branching fraction averaged over l = e, mu, B((B) over bar (0) -> D*(+)l(-)(nu) over bar (l)) = (4.90 +/- 0.07(stat.)(-0.35)(+0.36)(syst.))%. We measure the differential decay rate as a function of iv, the relativistic boost gamma of the D*+ in the Wo rest frame. By extrapolating d Gamma/dw to the kinematic limit w -> 1, we extract the product of vertical bar V(cb)vertical bar and the axial form factor A(1)(w = 1). We combine this measurement with a lattice QCD calculation of A(1)(w = 1) to determine vertical bar V(cb)vertical bar = (38.7 +/- 0.3(stat.) +/- 1.7(syst.)(-1.3)(+1.5)(theory)) x 10(-3).We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| based on a sample of about 53 700 B{sup 0}{yields}D*{sup +}l{sup -}{nu}{sub l} decays observed by the BABAR detector. We obtain the branching fraction averaged over l=e,{mu}, B(B{sup 0}{yields}D*{sup +}l{sup -}{nu}{sub l})=(4.90{+-}0.07(stat.){sub -0.35}{sup +0.36}(syst.))%. We measure the differential decay rate as a function of w, the relativistic boost {gamma} of the D*{sup +} in the B{sup 0} rest frame. By extrapolating d{gamma}/dw to the kinematic limit w{yields}1, we extract the product of |V{sub cb}| and the axial form factor A{sub 1}(w=1). We combine this measurement with a lattice QCD calculation of A{sub 1}(w=1) to determine |V{sub cb}|=(38.7{+-}0.3(stat.){+-}1.7(syst.){sub -1.3}{sup +1.5}(theory))x10{sup -3}.We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| based on a sample of about 53 700 B 0→D*+l-ν l decays observed by the BABAR detector. We obtain the branching fraction averaged over l=e,μ, B(B 0→D*+l-ν l)=(4.90±0.07(stat.)-0.35+0.36(syst.))%. We measure the differential decay rate as a function of w, the relativistic boost γ of the D*+ in the B 0 rest frame. By extrapolating dΓ/dw to the kinematic limit w→1, we extract the product of |Vcb| and the axial form factor A1(w=1). We combine this measurement with a lattice QCD calculation of A1(w=1) to determine |Vcb|=(38.7±0.3(stat.)±1.7(syst.)-1.3+1.5(theory))×10-3.