Using 467 fb − 1 of e + e − annihilation data collected with the B A B AR detector, we measure B ( τ − → µ − ν µ ν τ ) B ( τ − → e − ν e ν τ ) =(0 . 9796 ± 0 . 0016 ± 0 . 0036), B ( − → π ) B ( τ − → e − ν e ν τ ) =(0 . 5945 ± 0 . 0014 ± 0 . 0061), and B ( τ − → K − ν τ ) B ( τ − → e − ν e ν τ ) =(0 . 03882 ± 0 . 00032 ± 0 . 00057), where the uncertainties are statistical and systematic, respectively. From these precision τ measurements, we test the Standard Model assumption of µ - e and τ - µ charge current lepton universality and provide determinations of | V us | experimentally independent of the decay of a kaon.

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.

The B-s(0)-(B) over bar (0)(s) oscillation frequency Delta m(s) is measured with 36 pb(-1) of data collected in pp collisions at = 7 TeV by the LHCb experiment at the Large Hadron Collider. A total of 1381 B-s(0) -> D-s(-) pi(+) and B-s(0) -> D-s(-) pi(+)pi(-)pi(+) signal decays are reconstructed, with average decay time resolutions of 44 fs and 36 fs, respectively. An oscillation signal with a statistical significance of 4.6 sigma is observed. The measured oscillation frequency is Delta m(s) = 17.63 +/- 0.11 (stat) +/-0.02 (syst)ps(-1) (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.

The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of 37.5 pb(-1) collected with the LHCb detector. The production cross-section for pairs with both J/psi in the rapidity range 2 < y(J/psi) < 4.5 and transverse momentum p(T)(J/psi) < 10 GeV/c issigma(J/psi J/psi) = 5.1 +/- 1.0 +/- 1.1 nb,where the first uncertainty is statistical and the second systematic. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.

We present results for B-meson decay modes involving a charm meson, protons, and pions using 455 x 10^6 BBbar pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e+ e- collider. The branching fractions are measured for the following ten decays: B0bar to D0 p pbar, B0bar to D*0 p pbar, B0bar to D+ p pbar pi-, B0bar to D*+ p pbar pi-, B- to D0 p pbar pi-, B- to D*0 p pbar pi-, B0bar to D0 p pbar pi- pi+, B0bar to D*0 p pbar pi- pi+, B- to D+ p pbar pi- pi-, and B- to D*+ p pbar pi- pi-, The four B- and the two five-body B0bar modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(p pbar) and M(D(*)0 p) invariant mass distributions show enhancements near threshold values. In the four-body mode B0bar to D+ p pbar pi-, the M(p pi-) distribution shows a narrow structure of unknown origin near 1.5 GeV/c^2. The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.

P. del Amo Sanchez, J. P. Lees, V. Poireau, E. Prencipe, V. Tisserand, J. Garra Tico, E. Grauges, M. Martinelli, A. Palano, M. Pappagallo, G. Eigen, B. Stugu, L. Sun, M. Battaglia, D.N. Brown, B. Hooberman, L. T. Kerth, Yu. G. Kolomensky, G. Lynch, I. L. Osipenkov, T. Tanabe, C.M. Hawkes, A. T. Watson, H. Koch, T. Schroeder, D. J. Asgeirsson, C. Hearty, T. S. Mattison, J. A. McKenna, A. Khan, A. Randle-Conde, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, V. B. Golubev, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, E. P. Solodov, K.Yu. Todyshev, A.N. Yushkov, M. Bondioli, S. Curry, D. Kirkby, A. J. Lankford, M. Mandelkern, E. C. Martin, D. P. Stoker, H. Atmacan, J.W. Gary, F. Liu, O. Long, G.M. Vitug, C. Campagnari, J.M. Flanigan, T.M. Hong, D. Kovalskyi, J. D. Richman, C. West, A.M. Eisner, C. A. Heusch, J. Kroseberg, W. S. Lockman, A. J. Martinez, T. Schalk, B.A. Schumm, A. Seiden, L. O. Winstrom, C.H. Cheng, D. A. Doll, B. Echenard, D. G. Hitlin, P. Ongmongkolkul, F. C. Porter, A.Y. Rakitin, R. Andreassen, M. S. Dubrovin, G. Mancinelli, B. T. Meadows, M.D. Sokoloff, P. C. Bloom, W. T. Ford, A. Gaz, M. Nagel, U. Nauenberg, J. G. Smith, S. R. Wagner, R. Ayad,* W.H. Toki, H. Jasper, T.M. Karbach, J. Merkel, A. Petzold, B. Spaan, K. Wacker, M. J. Kobel, K. R. Schubert, R. Schwierz, D. Bernard, M. Verderi, P. J. Clark, S. Playfer, J. E. Watson, M. Andreotti, D. Bettoni, C. Bozzi, R. Calabrese, A. Cecchi, G. Cibinetto, E. Fioravanti, P. Franchini, E. Luppi, M. Munerato, M. Negrini, A. Petrella, L. Piemontese, R. Baldini-Ferroli, A. Calcaterra, R. de Sangro, G. Finocchiaro, M. Nicolaci, S. Pacetti, P. Patteri, I.M. Peruzzi, M. Piccolo, M. Rama, A. Zallo, R. Contri, E. Guido, M. Lo Vetere, M. R. Monge, S. Passaggio, C. Patrignani, E. Robutti, S. Tosi, B. Bhuyan, V. Prasad, C. L. Lee, M. Morii, A. Adametz, J. Marks, U. Uwer, F. U. Bernlochner, M. Ebert, H.M. Lacker, T. Lueck, A. Volk, P. D. Dauncey, M. Tibbetts, P. K. Behera, U. Mallik, C. Chen, J. Cochran, H. B. Crawley, L. Dong, W. T. Meyer, S. Prell, E. I. Rosenberg, A. E. Rubin, A.V. Gritsan, Z. J. Guo, N. Arnaud, M. Davier, D. Derkach, J. Firmino da Costa, G. Grosdidier, F. Le Diberder, A.M. Lutz, B. Malaescu, A. Perez, P. Roudeau, M.H. Schune, J. Serrano, V. Sordini, A. Stocchi, L. Wang, G. Wormser, D. J. Lange, D.M. Wright, I. Bingham, C.A. Chavez, J. P. Coleman, J. R. Fry, E. Gabathuler, R. Gamet, D. E. Hutchcroft, D. J. Payne, C. Touramanis, A. J. Bevan, F. Di Lodovico, R. Sacco, M. Sigamani, G. Cowan, S. Paramesvaran, A. C. Wren, D.N. Brown, C. L. Davis, A.G. Denig, M. Fritsch, W. Gradl, A. Hafner, K. E. Alwyn, D. Bailey, R. J. Barlow, G. Jackson, G. D. Lafferty, J. Anderson, R. Cenci, A. Jawahery, D. A. Roberts, G. Simi, J.M. Tuggle, C. Dallapiccola, E. Salvati, R. Cowan, D. Dujmic, G. Sciolla, M. Zhao, D. Lindemann, P.M. Patel, S. H. Robertson, M. Schram, P. Biassoni, A. Lazzaro, V. Lombardo, F. Palombo, S. Stracka, L. Cremaldi, R. Godang, R. Kroeger, P. Sonnek, D. J. Summers, X. Nguyen, M. Simard, P. Taras, G. De Nardo, D. Monorchio, G. Onorato, C. Sciacca, G. Raven, H. L. Snoek, C. P. Jessop, K. J. Knoepfel, J.M. LoSecco, W. F. Wang, L. A. Corwin, K. Honscheid, R. Kass, J. P. Morris, N. L. Blount, J. Brau, R. Frey, O. Igonkina, J. A. Kolb, R. Rahmat, N. B. Sinev, D. Strom, J. Strube, E. Torrence, G. Castelli, E. Feltresi, N. Gagliardi, M. Margoni, M. Morandin, M. Posocco, M. Rotondo, F. Simonetto, R. Stroili, E. Ben-Haim, G. R. Bonneaud, H. Briand, G. Calderini, J. Chauveau, O. Hamon, Ph. Leruste, G. Marchiori, J. Ocariz, J. Prendki, S. Sitt, M. Biasini, E. Manoni, A. Rossi, C. Angelini, G. Batignani, S. Bettarini, M. Carpinelli,57a,57b,k G. Casarosa, A. Cervelli, F. Forti, M.A. Giorgi, A. Lusiani, N. Neri, E. Paoloni, G. Rizzo, J. J. Walsh, D. Lopes Pegna, C. Lu, J. Olsen, A. J. S. Smith, A.V. Telnov, F. Anulli, E. Baracchini, G. Cavoto, R. Faccini, F. Ferrarotto, F. Ferroni, M. Gaspero, L. Li Gioi, M.A. Mazzoni, G. Piredda, F. Renga, T. Hartmann, T. Leddig, H. Schröder, R. Waldi, T. Adye, B. Franek, E. O. Olaiya, F. F. Wilson, S. Emery, G. Hamel de Monchenault, G. Vasseur, Ch. Yèche, M. Zito, M. T. Allen, D. Aston, D. J. Bard, R. Bartoldus, J. F. Benitez, C. Cartaro, M. R. Convery, J. Dorfan, G. P. Dubois-Felsmann, W. Dunwoodie, R. C. Field, M. Franco Sevilla, B.G. Fulsom, A.M. Gabareen, M. T. Graham, P. Grenier, C. Hast, W.R. Innes, M.H. Kelsey, H. Kim, P. Kim, M. L. Kocian, D.W.G. S. Leith, S. Li, B. Lindquist, S. Luitz, V. Luth, H. L. Lynch, D. B. MacFarlane, H. Marsiske, D. R. Muller, H. Neal, S. Nelson, C. P. O’Grady, I. Ofte, M. Perl, T. Pulliam, B. N. Ratcliff, A. Roodman, A.A. Salnikov, V. Santoro, R. H. Schindler, J. Schwiening, A. Snyder, D. Su, M.K. Sullivan, S. Sun, PHYSICAL REVIEW D 85, 092017 (2012)

We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×106 BB pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e^+e^- collider. The branching fractions are measured for the following ten decays: B ^0→D^0pp, B^0→D^(*0)pp, B^0→D^(*+)ppπ^-, B^0→D^(*+)ppπ^-, B-→D0ppπ^-, B-→D^(*0)ppπ^-, B^0→D^0pp π^-π^+, B^0→D^(*0)pp π^-π^+, B^-→D^+pp π^-π^-, and B^-→D^(*+)pp π^-π^-. The four B^- and the two five-body B^0 modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(pp) and M(D^((*)0)p) invariant-mass distributions show enhancements near threshold values. In the four-body mode B^0→D^+ppπ^-, the M(pπ^-) distribution shows a narrow structure of unknown origin near 1.5  GeV/c^2. The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.

The first observation of the decay B-s(0) -> K*(0)(K) over bar*(0) is reported using 35 pb(-1) of data collected by LHCb in proton-proton collisions at a centre-of-mass energy of 7 TeV. A total of 49.8 +/- 7.5 B-s(0) -> (K+pi(-))(K-pi(+)) events are observed within +/- 50 MeV/c(2) of the B-s(0) mass and 746 MeV/c(2) < m(K pi) < 1046 MeV/c(2), mostly coming from a resonant B-s(0) -> K*(0)(K) over bar*(0) signal. The branching fraction and the CP-averaged K*(0) longitudinal polarization fraction are measured to B(B-s(0) -> K*(0)(K) over bar*(0)) = (2.81 +/- 0.46(stat.) +/- 0.45(syst.) +/- 0.34(f(s)/f(d))) x 10(-5) and f(L) = 0.31 +/- 0.12(stat.) +/- 0.04(syst.). (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.

The relative abundance of the three decay modes B(0)→D(-)K(+), B(0)→D(-)π(+), and B(s)(0)→D(s)(-)π(+) produced in 7 TeV pp collisions at the LHC is determined from data corresponding to an integrated luminosity of 35 pb(-1). The branching fraction of B(0)→D(-)K(+) is found to be B(B(0)→D(-)K(+)) = (2.01 ± 0.18(stat) ± 0.14(syst)) × 10(-4). The ratio of fragmentation fractions f(s)/f(d) is determined through the relative abundance of B(s)(0)→D(s)(-)π(+) to B(0)→D(-)K(+) and B(0)→D(-)π(+), leading to f(s)/f(d) = 0.253 ± 0.017 ± 0.017 ± 0.020, where the uncertainties are statistical, systematic, and theoretical, respectively.

Using data collected with the LHCb detector in proton-proton collisions at a centreof-mass energy of 7 TeV, the hadronic decay B s → J/ψf0(980) is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the B s system. Using a fit to the π π mass spectrum with interfering resonances gives Rf0/φ ≡ Γ(B s →J/ψf0, f0→ππ) Γ(B0 s →J/ψφ, φ→K+K−) = 0.252 −0.032−0.033. In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find R ′ ≡ Γ(B s→J/ψππ, |m(ππ)−980 MeV|<90 MeV) Γ(B0 s →J/ψφ, φ→K+K−) = 0.162 ± 0.022 ± 0.016, where in both cases the uncertainties are statistical and systematic, respectively.

We present a measurement of the branching fractions of the 22 decay channels of the B-0 and B+ mesons to (D) over bar (()*()) D-(*()) K, where the D-(*()) and (D) over bar (()*()) mesons are fully reconstructed. Summing the 10 neutral modes and the 12 charged modes, the branching fractions are found to be B(B-0 -> (D) over bar (()*()) D-(*()) K) = (3.68 +/- 0.10 +/- 0.24)% and B(B+ -> (D) over bar (()*()) D-(*()) K) = (4.05 +/- 0.11 +/- 0.28)%, where the first uncertainties are statistical and the second systematic. The results are based on 429 fb(-1) of data containing 471 X 10(6)B (B) over bar pairs collected at the Y(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory.

The \( {{{\bar{\it{\Lambda} }}} \left/ {\it{\Lambda} } \right.} \) and \( {{{\bar{\it{\Lambda} }}} \left/ {{K_S^0}} \right.} \) production ratios are measured by the LHCb detector from 0.3 nb−1 of pp collisions delivered by the LHC at \( \sqrt {s} = 0.9 \) TeV and 1.8 nb−1 at \( \sqrt {s} = 7 \) TeV. Both ratios are presented as a function of transverse momentum, p T, and rapidity, y, in the ranges 0.15 < p T < 2.50 GeV/c and 2.0 < y < 4.5. Results at the two energies are in good agreement as a function of rapidity loss, ∆y = y beam − y, and are consistent with previous measurements. The ratio \( {{{\bar{\it{\Lambda} }}} \left/ {\it{\Lambda}} \right.} \), measuring the transport of baryon number from the collision into the detector, is smaller in data than predicted in simulation, particularly at high rapidity. The ratio \( {{{\bar{\it{\Lambda}}}} \left/ {{K_S^0}} \right.} \), measuring the baryon-to-meson suppression in strange quark hadronisation, is significantly larger than expected.

We study the processes gamma gamma -> K-S(0) K-+ pi(-+) and gamma gamma -> K+K- pi(+)pi(-)pi(0) using a data sample of 519: 2fb(-1) recorded by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the Y(nS) (n = 2, 3, 4) resonances. We observe the eta(c) (1S), chi(c0) (1P) and eta(c) (2S) resonances produced in two-photon interactions and decaying to K+K- pi(+)pi(-)pi(0), with significances of 18.1, 5.4 and 5.3 standard deviations (including systematic errors), respectively, and report 4.0 sigma evidence of the X-c2(1P) decay to this final state. We measure the eta(c)(2S) mass and width in K-S(0) K+- pi(+-) decays, and obtain the values m(eta(c)(2S)) = 3638: 5 +/- 1.5 +/- 0.8 MeV/c(2) and Gamma(eta(c)(2S)) = 13.4 +/- 4: 6 +/- 3.2 MeV, where the first uncertainty is statistical and the second is systematic. We measure the two-photon width times branching fraction for the reported resonance signals, and search for the X-c2 (2P) resonance, but no significant signal is observed.

We report the observation of the decay B- -> D-s(()*()+)K(-)l(-)(nu) over bar (l) based on 342 fb(-1) of data collected at the Y(4S) 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- -> D-s(()*()+)K(-)l(-)(nu) over bar (l) with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B- -> D-s(()*())K(-)l(-)(nu) over bar (l) = [6.13(-1.03)(+1.04)(stat) +/- 0.43(syst) +/- 0.51 (B(D-s))] X 10(-4), where the last error reflects the limited knowledge of the D-s branching fractions.