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Measurements of the B→D* form factors using the decay B̄0→D*+e-ν̄e

Physical Review D Particles Fields Gravitation and Cosmology 74:9 (2006)

Authors:

B Aubert, R Barate, D Boutigny, F Couderc, Y Karyotakis, JP Lees, V Poireau, V Tisserand, A Zghiche, E Grauges, A Palano, M Pappagallo, JC Chen, ND Qi, G Rong, P Wang, YS Zhu, G Eigen, I Ofte, B Stugu, GS Abrams, M Battaglia, DS Best, DN Brown, J Button-Shafer, RN Cahn, E Charles, CT Day, MS Gill, AV Gritsan, Y Groysman, RG Jacobsen, RW Kadel, J Kadyk, LT Kerth, YG Kolomensky, G Kukartsev, G Lynch, LM Mir, PJ Oddone, TJ Orimoto, M Pripstein, NA Roe, MT Ronan, WA Wenzel, M Barrett, KE Ford, TJ Harrison, AJ Hart, CM Hawkes, SE Morgan, AT Watson, M Fritsch, K Goetzen, T Held, H Koch, B Lewandowski, M Pelizaeus, K Peters, T Schroeder, M Steinke, JT Boyd, JP Burke, WN Cottingham, D Walker, T Cuhadar-Donszelmann, BG Fulsom, C Hearty, NS Knecht, TS Mattison, JA McKenna, A Khan, P Kyberd, M Saleem, L Teodorescu, VE Blinov, AD Bukin, VP Druzhinin, VB Golubev, EA Kravchenko, AP Onuchin, SI Serednyakov, YI Skovpen, EP Solodov, KY Todyshev, M Bondioli, M Bruinsma, M Chao, S Curry, I Eschrich, D Kirkby, AJ Lankford, P Lund, M Mandelkern, RK Mommsen, W Roethel, DP Stoker, S Abachi, C Buchanan, SD Foulkes

Abstract:

We measure the dependence of B̄0→D*+e-ν̄e on the decay angles and momentum transfer. The data sample consists of ∼86×106 BB̄-pairs accumulated on the Υ(4S) resonance by the BABAR detector at the asymmetric e+e- collider PEP-II. We specify the three form factors by two ratios R1 and R2, and by a single parameter ρ2 characterizing the polynomial representing hA1, the function which describes the momentum-transfer dependence of the form factor A1. We determine R1, R2, and ρ2 using an unbinned maximum likelihood fit to the full decay distribution. The results are R1=1.396±0.060±0.035±0.027, R2=0.885±0.040±0.022±0.013, and ρ2=1.145±0. 059±0.030±0.035. The stated uncertainties are the statistical from the data, statistical from the size of the Monte Carlo sample and the systematic uncertainty, respectively. In addition, based on this measurement, we give an updated value for the CKM matrix element |Vcb|. © 2006 The American Physical Society.

Observation of Bs 0 - B̄s 0 oscillations

Physical Review Letters 97:24 (2006)

Authors:

A Abulencia, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Budroni, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, S Carrillo, D Carlsmith, R Carosi, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, M Ciljak, CI Ciobanu

Abstract:

We report the observation of Bs 0- B̄s 0 oscillations from a time-dependent measurement of the Bs 0-̄s 0 oscillation frequency Δms. Using a data sample of 1 fb-1 of pp collisions at √ = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic B s decays, 3100 partially reconstructed hadronic Bs decays, and 61500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for Bs 0-̄s 0 oscillations. The probability that random fluctuations could produce a comparable signal is 8 × 10-8, which exceeds 5σ significance. We measure Δms = 17.77 ± 0.10(stat) ± 0.07(syst) ps-1 and extract |Vtd/Vts| = 0.2060 ± 0.0007(Δs)-0.0060 +0.0081 (Δd + theor). © 2006 The American Physical Society.

Observation of Υ(4S) Decays to π+π-Υ(1S) and π+π-Υ(2S)

Physical Review Letters 96:23 (2006)

Authors:

B Aubert, R Barate, M Bona, D Boutigny, F Couderc, Y Karyotakis, JP Lees, V Poireau, V Tisserand, A Zghiche, E Grauges, A Palano, JC Chen, ND Qi, G Rong, P Wang, YS Zhu, G Eigen, I Ofte, B Stugu, GS Abrams, M Battaglia, DN Brown, J Button-Shafer, RN Cahn, E Charles, MS Gill, Y Groysman, RG Jacobsen, JA Kadyk, LT Kerth, YG Kolomensky, G Kukartsev, G Lynch, LM Mir, PJ Oddone, TJ Orimoto, M Pripstein, NA Roe, MT Ronan, WA Wenzel, M Barrett, KE Ford, TJ Harrison, AJ Hart, CM Hawkes, SE Morgan, AT Watson, K Goetzen, T Held, H Koch, B Lewandowski, M Pelizaeus, K Peters, T Schroeder, M Steinke, JT Boyd, JP Burke, WN Cottingham, D Walker, T Cuhadar-Donszelmann, BG Fulsom, C Hearty, NS Knecht, TS Mattison, JA McKenna, A Khan, P Kyberd, M Saleem, L Teodorescu, VE Blinov, AD Bukin, VP Druzhinin, VB Golubev, AP Onuchin, SI Serednyakov, YI Skovpen, EP Solodov, KY Todyshev, DS Best, M Bondioli, M Bruinsma, M Chao, S Curry, I Eschrich, D Kirkby, AJ Lankford, P Lund, M Mandelkern, RK Mommsen, W Roethel, DP Stoker, S Abachi, C Buchanan, SD Foulkes, JW Gary, O Long, BC Shen, K Wang, L Zhang

Abstract:

We present the first measurement of Υ(4S) decays to π+π-Υ(1S) and π+π-Υ(2S) based on a sample of 230×106Υ(4S) mesons collected with the BABAR detector. We measure the product branching fractions B(Υ(4S)→π+π-Υ(1S)) ×B(Υ(1S)→μ+μ-)=(2.23±0.25stat±0.27syst) ×10-6 and B(Υ(4S)→π+π-Υ(2S))×B(Υ(2S) →μ+μ-)=(1.69±0.26stat±0.20syst)×10-6, from which we derive the partial widths Γ(Υ(4S)→π+π-Υ(1S))=(1. 8±0.4)keV and Γ(Υ(4S)→π+π-Υ(2S))=(2. 7±0.8)keV. © 2006 The American Physical Society.

Precision electroweak measurements on the Z resonance

Physics Reports 427:5-6 (2006) 257-454

Authors:

JA Bagger, M Grünewald, S Schael, R Barate, R Brunelière, D Buskulic, I De Bonis, D Decamp, P Ghez, C Goy, S Jézéquel, JP Lees, A Lucotte, F Martin, E Merle, MN Minard, JY Nief, P Odier, B Pietrzyk, B Trocmé, S Bravo, MP Casado, M Chmeissani, P Comas, JM Crespo, E Fernandez, M Fernandez-Bosman, L Garrido, E Grauges, A Juste, M Martinez, G Merino, R Miquel, LM Mir, S Orteu, A Pacheco, IC Park, J Perlas, I Riu, H Ruiz, F Sanchez, A Colaleo, D Creanza, N De Filippis, M De Palma, G Iaselli, G Maggi, M Maggi, S Nuzzo, A Ranieri, G Raso, F Ruggieri, G Selvaggi, L Silvestris, P Tempesta, A Tricomi, G Zito, X Huang, J Lin, Q Ouyang, T Wang, Y Xie, R Xu, S Xue, J Zhang, L Zhang, W Zhao, D Abbaneo, A Bazarko, U Becker, G Boix, F Bird, E Blucher, B Bonvicini, P Bright-Thomas, T Barklow, O Buchmüller, M Cattaneo, F Cerutti, V Ciulli, B Clerbaux, H Drevermann, RW Forty, M Frank, TC Greening, R Hagelberg, AW Halley, F Gianotti, M Girone, JB Hansen, J Harvey, R Jacobsen, DE Hutchcroft, P Janot, B Jost, J Knobloch, M Kado, I Lehraus, P Lazeyras, P Maley

Abstract:

We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, mZ and ΓZ, and its couplings to fermions, for example the ρ parameter and the effective electroweak mixing angle for leptons, are precisely measured: mZ = 91.1875 ± 0.0021 GeV, ΓZ = 2.4952 ± 0.0023 GeV, ρl = 1.0050 ± 0.0010, sin2 θlept eff = 0.23153 ± 0.00016. The number of light neutrino species is determined to be 2.9840 ± 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, mt = 173+13 -10 GeV, and the mass of the W boson, mW = 80.363 ± 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of mt and mW, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level.

Search for B+→ π+ and B0→ π0 decays

Physical Review D Particles Fields Gravitation and Cosmology 74:1 (2006)

Authors:

B Aubert, R Barate, M Bona, D Boutigny, F Couderc, Y Karyotakis, JP Lees, V Poireau, V Tisserand, A Zghiche, E Grauges, A Palano, M Pappagallo, JC Chen, ND Qi, G Rong, P Wang, YS Zhu, G Eigen, I Ofte, B Stugu, GS Abrams, M Battaglia, DN Brown, J Button-Shafer, RN Cahn, E Charles, CT Day, MS Gill, Y Groysman, RG Jacobsen, JA Kadyk, LT Kerth, YG Kolomensky, G Kukartsev, G Lynch, LM Mir, PJ Oddone, TJ Orimoto, M Pripstein, NA Roe, MT Ronan, WA Wenzel, M Barrett, KE Ford, TJ Harrison, AJ Hart, CM Hawkes, SE Morgan, AT Watson, K Goetzen, T Held, H Koch, B Lewandowski, M Pelizaeus, K Peters, T Schroeder, M Steinke, JT Boyd, JP Burke, WN Cottingham, D Walker, T Cuhadar-Donszelmann, BG Fulsom, C Hearty, NS Knecht, TS Mattison, JA McKenna, A Khan, P Kyberd, M Saleem, L Teodorescu, VE Blinov, AD Bukin, VP Druzhinin, VB Golubev, AP Onuchin, SI Serednyakov, YI Skovpen, EP Solodov, KY Todyshev, DS Best, M Bondioli, M Bruinsma, M Chao, S Curry, I Eschrich, D Kirkby, AJ Lankford, P Lund, M Mandelkern, RK Mommsen, W Roethel, DP Stoker, S Abachi, C Buchanan, SD Foulkes, JW Gary, O Long, BC Shen

Abstract:

A search has been made for the decays B+→ π+ and B0→ π0 in a data sample of approximately 232×106 BB̄ pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. No significant signals have been observed, and therefore upper limits have been set on the branching fractions: B(B+→ π+)<2.4×10-7 and B(B0→ π0)<2.8×10-7 at 90% probability. © 2006 The American Physical Society.