J Albert

Publications of J Albert

• Observation of a New χ_{b} State in Radiative Transitions to Υ(1S) and Υ(2S) at ATLAS.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, O S Abouzeid, H Abramowicz [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 04/2012; 108(15):152001.

  The χ_{b}(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at sqrt[s]=7  TeV and recorded by the ATLAS detector. Using a data sample corresponding to anThe χ_{b}(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at sqrt[s]=7  TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4  fb^{-1}, these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ→μ^{+}μ^{-}. In addition to the mass peaks corresponding to the decay modes χ_{b}(1P,2P)→Υ(1S)γ, a new structure centered at a mass of 10.530±0.005(stat)±0.009(syst)  GeV is also observed, in both the Υ(1S)γ and Υ(2S)γ decay modes. This structure is interpreted as the χ_{b}(3P) system.

• Search for the Higgs Boson in the H→WW^{(*)}→l^{+}νl^{-}ν[over ¯] Decay Channel in pp Collisions at sqrt[s]=7  TeV with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 03/2012; 108(11):111802.

  A search for the Higgs boson has been performed in the H→WW^{(*)}→ℓ^{+}νℓ^{-}ν[over ¯] channel (ℓ=e/μ) with an integrated luminosity of 2.05  fb^{-1} of pp collisions at sqrt[s]=7  TeV collected withA search for the Higgs boson has been performed in the H→WW^{(*)}→ℓ^{+}νℓ^{-}ν[over ¯] channel (ℓ=e/μ) with an integrated luminosity of 2.05  fb^{-1} of pp collisions at sqrt[s]=7  TeV collected with the ATLAS detector at the Large Hadron Collider. No significant excess of events over the expected background is observed and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 110  GeV<m_{H}<300  GeV. The observations exclude the presence of a standard model Higgs boson with a mass 145<m_{H}<206  GeV at 95% confidence level.

• Search for the Standard Model Higgs Boson in the Diphoton Decay Channel with 4.9  fb^{-1} of pp Collision Data at sqrt[s]=7  TeV with ATLAS.

  Authors: G Aad, B Abbott, J Abdallah, S Abdel Khalek, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, O S Abouzeid [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 03/2012; 108(11):111803.

  A search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9  fb^{-1} collected with the ATLAS detector at theA search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9  fb^{-1} collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of sqrt[s]=7  TeV. In the diphoton mass range 110-150 GeV, the largest excess with respect to the background-only hypothesis is observed at 126.5 GeV, with a local significance of 2.8 standard deviations. Taking the look-elsewhere effect into account in the range 110-150 GeV, this significance becomes 1.5 standard deviations. The standard model Higgs boson is excluded at 95% confidence level in the mass ranges of 113-115 GeV and 134.5-136 GeV.

• Measurement of the ZZ Production Cross Section and Limits on Anomalous Neutral Triple Gauge Couplings in Proton-Proton Collisions at sqrt[s]=7  TeV with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 01/2012; 108(4):041804.

  A measurement of the ZZ production cross section in proton-proton collisions at sqrt[s]=7  TeV using data corresponding to an integrated luminosity of 1.02  fb^{-1} recorded by the ATLAS experimentA measurement of the ZZ production cross section in proton-proton collisions at sqrt[s]=7  TeV using data corresponding to an integrated luminosity of 1.02  fb^{-1} recorded by the ATLAS experiment at the LHC is presented. Twelve events containing two Z boson candidates decaying to electrons and/or muons are observed, with an expected background of 0.3±0.3(stat)_{-0.3}^{+0.4}(syst) events. The cross section measured in a phase-space region with good detector acceptance and for dilepton masses within the range 66 to 116 GeV is σ_{ZZ→ℓ^{+}ℓ^{-}ℓ^{+}ℓ^{-}}^{fid}=19.4_{-5.2}^{+6.3}(stat)_{-0.7}^{+0.9}(syst)±0.7(lumi)  fb. The resulting total cross section for on-shell ZZ production, σ_{ZZ}^{tot}=8.5_{-2.3}^{+2.7}(stat)_{-0.3}^{+0.4}(syst)±0.3(lumi)  pb, is consistent with the standard model expectation of 6.5_{-0.2}^{+0.3}  pb calculated at the next-to-leading order in QCD. Limits on anomalous neutral triple gauge boson couplings are derived.

• Search for New Phenomena in tt[over ¯] Events with Large Missing Transverse Momentum in Proton-Proton Collisions at sqrt[s]=7  TeV with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 01/2012; 108(4):041805.

  A search for new phenomena in tt[over ¯] events with large missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The measurement is based onA search for new phenomena in tt[over ¯] events with large missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The measurement is based on 1.04  fb^{-1} of data collected with the ATLAS detector at the LHC. Contributions to this final state may arise from a number of standard model extensions. The results are interpreted in terms of a model where new top-quark partners are pair produced and each decay to an on-shell top (or antitop) quark and a long-lived undetected neutral particle. The data are found to be consistent with standard model expectations. A limit at 95% confidence level is set excluding a cross section times branching ratio of 1.1 pb for a top-partner mass of 420 GeV and a neutral particle mass less than 10 GeV. In a model of exotic fourth generation quarks, top-partner masses are excluded up to 420 GeV and neutral particle masses up to 140 GeV.

• Initial-State Radiation Measurement of the e+e- -> pi+pi-pi+pi- Cross Section

  Authors: J. P. Lees, V. Poireau, V. Tisserand, J. Garra Tico, E. Grauges, M. Martinelli, D. A. Milanes, A. Palano, M. Pappagallo, G. Eigen [......] N. Tasneem, T. J. Gershon, P. F. Harrison, T. E. Latham, E. M. T. Puccio, H. R. Band, S. Dasu, Y. Pan, R. Prepost, S. L. Wu

  01/2012;

  We study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb^-1 of data collected with the BABAR detector at SLAC, correspondingWe study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb^-1 of data collected with the BABAR detector at SLAC, corresponding to approximately 260,000 signal events. We use these data to extract the non-radiative sigma(e+e- ->pi+pi-pi+pi-) cross section in the energy range from 0.6 to 4.5 Gev. The total uncertainty of the cross section measurement in the peak region is less than 3%, higher in precision than the corresponding results obtained from energy scan data.

• Search for Dilepton Resonances in pp Collisions at sqrt[s]=7  TeV with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 12/2011; 107(27):272002.

  This Letter reports on a search for narrow high-mass resonances decaying into dilepton final states. The data were recorded by the ATLAS experiment in pp collisions at sqrt[s]=7  TeV at the LargeThis Letter reports on a search for narrow high-mass resonances decaying into dilepton final states. The data were recorded by the ATLAS experiment in pp collisions at sqrt[s]=7  TeV at the Large Hadron Collider and correspond to a total integrated luminosity of 1.08 (1.21)  fb^{-1} in the e^{+}e^{-} (μ^{+}μ^{-}) channel. No statistically significant excess above the standard model expectation is observed and upper limits are set at the 95% C.L. on the cross section times branching fraction of Z^{'} resonances and Randall-Sundrum gravitons decaying into dileptons as a function of the resonance mass. A lower mass limit of 1.83 TeV on the sequential standard model Z^{'} boson is set. A Randall-Sundrum graviton with coupling k/M[over ¯]_{Pl}=0.1 is excluded at 95% C.L. for masses below 1.63 TeV.

• Giant enhancement of the second harmonic generation efficiency in poled multilayered silica glass structures.

  Authors: Ksenia Yadav, C L Callender, C W Smelser, C Ledderhof, C Blanchetiere, S Jacob, J Albert

  Optics express. 12/2011; 19(27):26975-83.

  Multilayered thin-film doped silica structures are experimentally demonstrated as an effective tool to enhance the second-order nonlinear properties induced in thermally poled glass devices. AMultilayered thin-film doped silica structures are experimentally demonstrated as an effective tool to enhance the second-order nonlinear properties induced in thermally poled glass devices. A 204-fold improvement is obtained in the second harmonic generated (SHG) in a poled structure with a 3 μm-thick multilayered stack consisting of sub- 100 nm-thick alternating germanium-doped and undoped silica layers compared to poled bulk silica glass. The induced nonlinearity is localized within the layered region, indicating that the multilayered design can be used to precisely control the thickness and the location of the nonlinearity. Such artificial nonlinear structures can be used to overcome the main limitations of existing poled glass devices, therefore opening the door to practical implementations of efficient active devices in silica glass.

• Search for the Higgs Boson in the H→WW→lνjj Decay Channel in pp Collisions at sqrt[s]=7  TeV with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 12/2011; 107(23):231801.

  A search for a Higgs boson has been performed in the H→WW→ℓνjj channel in 1.04  fb^{-1} of pp collision data at sqrt[s]=7  TeV recorded with the ATLAS detector at the Large Hadron Collider. NoA search for a Higgs boson has been performed in the H→WW→ℓνjj channel in 1.04  fb^{-1} of pp collision data at sqrt[s]=7  TeV recorded with the ATLAS detector at the Large Hadron Collider. No significant excess of events is observed over the expected background and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 240  GeV<m_{H}<600  GeV. The best sensitivity is reached for m_{H}=400  GeV, where the 95% confidence level upper bound on the cross section for H→WW production is 3.1 pb, or 2.7 times the standard model prediction.

• Search for a Standard Model Higgs Boson in the H→ZZ→ℓ^{+}ℓ^{-}νν[over ¯] Decay Channel with the ATLAS Detector.

  Authors: G Aad, B Abbott, J Abdallah, A A Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu [......] R Zitoun, L Zivković, V V Zmouchko, G Zobernig, A Zoccoli, Y Zolnierowski, A Zsenei, M Zur Nedden, V Zutshi, L Zwalinski

  Physical review letters. 11/2011; 107(22):221802.

  A search for a heavy standard model Higgs boson decaying via H→ZZ→ℓ^{+}ℓ^{-}νν[over ¯], where ℓ=e, μ, is presented. It is based on proton-proton collision data at sqrt[s]=7  TeV, collected by theA search for a heavy standard model Higgs boson decaying via H→ZZ→ℓ^{+}ℓ^{-}νν[over ¯], where ℓ=e, μ, is presented. It is based on proton-proton collision data at sqrt[s]=7  TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04  fb^{-1}. The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340<m_{H}<450  GeV at the 95% confidence level.

• Search for Hadronic Decays of a Light Higgs Boson in the Radiative Decay Υ→γA^{0}.

  Authors: J P Lees, V Poireau, V Tisserand, J Garra Tico, E Grauges, M Martinelli, D A Milanes, A Palano, M Pappagallo, G Eigen [......] N Tasneem, T J Gershon, P F Harrison, T E Latham, E M T Puccio, H R Band, S Dasu, Y Pan, R Prepost, S L Wu

  Physical review letters. 11/2011; 107(22):221803.

  We search for hadronic decays of a light Higgs boson (A^{0}) produced in radiative decays of an Υ(2S) or Υ(3S) meson, Υ→γA^{0}. The data have been recorded by the BABAR experiment at the Υ(3S) andWe search for hadronic decays of a light Higgs boson (A^{0}) produced in radiative decays of an Υ(2S) or Υ(3S) meson, Υ→γA^{0}. The data have been recorded by the BABAR experiment at the Υ(3S) and Υ(2S) center-of-mass energies and include (121.3±1.2)×10^{6} Υ(3S) and (98.3±0.9)×10^{6} Υ(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Υ(nS)→γA^{0})B(A^{0}→hadrons) (n=2 or 3) that range from 1×10^{-6} for an A^{0} mass of 0.3  GeV/c^{2} to 8×10^{-5} at 7  GeV/c^{2}.

• A Measurement of the Semileptonic Branching Fraction of the B_s Meson

  Authors: The BaBar Collaboration, J. P. Lees, V. Poireau, V. Tisserand, J. Garra Tico, E. Grauges, M. Martinelli, D. A. Milanes, A. Palano, M. Pappagallo [......] N. Tasneem, T. J. Gershon, P. F. Harrison, T. E. Latham, E. M. T. Puccio, H. R. Band, S. Dasu, Y. Pan, R. Prepost, S. L. Wu

  10/2011;

  We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BaBar detector in the center-of-mass (CM) energy region above the Upsilon(4S)We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BaBar detector in the center-of-mass (CM) energy region above the Upsilon(4S) resonance. We use the inclusive yield of phi mesons and the phi yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B_s mesons relative to all B mesons as a function of CM energy. The inclusive semileptonic branching fraction of the B_s meson is determined to be B(B_s to l nu X)=9.5 (+2.5/-2.0)(stat)(+1.1/-1.9)(syst)%, where l indicates the average of e and mu.

• Search for hadronic decays of a light Higgs boson in the radiative decay Upsilon --> gamma A0

  Authors: The BABAR Collaboration, J P Lees, V Poireau, V Tisserand, J Garra Tico, E Grauges, M Martinelli, D. A. Milanes, A Palano, M Pappagallo [......] N. Tasneem, T. J. Gershon, P F Harrison, T E Latham, E. M. T. Puccio, H R Band, S Dasu, Y Pan, R Prepost, S L Wu

  08/2011;

  We search for hadronic decays of a light Higgs boson (A0) produced in radiative decays of an Upsilon(2S) or Upsilon(3S) meson, Upsilon --> gamma A0. The data have been recorded by the BABARWe search for hadronic decays of a light Higgs boson (A0) produced in radiative decays of an Upsilon(2S) or Upsilon(3S) meson, Upsilon --> gamma A0. The data have been recorded by the BABAR experiment at the Upsilon(3S) and Upsilon(2S) center of mass energies, and include (121.3 \pm 1.2) x 10^6 Upsilon(3S) and (98.3 \pm 0.9) x 10^6 Upsilon(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Upsilon(nS)-->gamma A0) x B(A0-->hadrons) (n=2 or 3) that range from 1 x 10^{-6} for an A0 mass of 0.3 GeV/c^2 to 8 x 10^{-5} at 7 GeV/c^2.

• Observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K-

  Authors: The BABAR Collaboration, J P Lees, V Poireau, V Tisserand, J Garra Tico, E Grauges, M Martinelli, D. A. Milanes, A Palano, M Pappagallo [......] T. J. Gershon, P F Harrison, T E Latham, E. M. T. Puccio, H R Band, S Dasu, Y Pan, R Prepost, C. O. Vuosalo, S L Wu

  08/2011;

  We report the observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K- with a significance larger than 7 standard deviations based on 471x10^6$ BBbar pairs collected with the BABARWe report the observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K- with a significance larger than 7 standard deviations based on 471x10^6$ BBbar pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B0bar --> Lambda_c^+ anti-Lambda K- to be (3.8 \pm 0.8_{stat} \pm 0.2_{sys} \pm 1.0_{Lambda_c^+})x10^{-5}. The uncertainties are statistical, systematic, and due to the uncertainty in the Lambda_c^+ branching fraction. We find that the Lambda_c^+ K^- invariant mass distribution shows an enhancement above 3.5 GeV/c^2.

• Observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ).

  Authors: P del Amo Sanchez, J P Lees, V Poireau, E Prencipe, V Tisserand, J Garra Tico, E Grauges, M Martinelli, A Palano, M Pappagallo [......] P F Harrison, T E Latham, E M T Puccio, H R Band, S Dasu, K T Flood, Y Pan, R Prepost, C O Vuosalo, S L Wu

  Physical review letters. 07/2011; 107(4):041804.

  We report the observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ) based on 342  fb(-1) of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+ e- storage rings at SLAC. AWe report the observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ) based on 342  fb(-1) of data collected at the Υ(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- ν(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- ν(ℓ)) = [6.13(-1.03)(+1.04)(stat)±0.43(syst)±0.51(B(D(s)))]×10(-4), where the last error reflects the limited knowledge of the D(s) branching fractions.

• Search for production of invisible final states in single-photon decays of Υ(1S).

  Authors: P del Amo Sanchez, J P Lees, V Poireau, E Prencipe, V Tisserand, J Garra Tico, E Grauges, M Martinelli, D A Milanes, A Palano [......] P F Harrison, T E Latham, E M T Puccio, H R Band, S Dasu, K T Flood, Y Pan, R Prepost, C O Vuosalo, S L Wu

  Physical review letters. 07/2011; 107(2):021804.

  We search for single-photon decays of the Υ(1S) resonance, Υ → γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A⁰, or a pair of dark matterWe search for single-photon decays of the Υ(1S) resonance, Υ → γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A⁰, or a pair of dark matter particles, χχ. Both A⁰ and χ are assumed to have zero spin. We tag Υ(1S) decays with a dipion transition Υ(2S) → π⁺π⁻Υ(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A⁰) ≤ 9.2 GeV and m(χ) ≤ 4.5 GeV in the sample of 98 × 10⁶ Υ(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.

• Study of radiative bottomonium transitions using converted photons

  Authors: The BABAR Collaboration, J P Lees, V Poireau, E Prencipe, V Tisserand, J. GarraTico, E Grauges, M Martinelli, D. A. Milanes, A Palano [......] T. J. Gershon, P F Harrison, T E Latham, E. M. T. Puccio, H R Band, S Dasu, Y Pan, R Prepost, C. O. Vuosalo, S L Wu

  04/2011;

  We use 111+/-1 million Upsilon(3S) and 89+/-1 million Upsilon(2S) events recorded by the BaBar detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomoniumWe use 111+/-1 million Upsilon(3S) and 89+/-1 million Upsilon(2S) events recorded by the BaBar detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been converted to e+e- pairs by the detector material. We observe Upsilon(3S) -> gamma chi_b0,2(1P) decay, make precise measurements of the branching fractions for chi_b1,2(1P,2P) -> gamma Upsilon(1S) and chi_b1,2(2P) -> gamma Upsilon(2S) decays, and search for radiative decay to the eta_b(1S) and eta_b(2S) states.

• Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)

  Authors: The BABAR Collaboration, J P Lees, V Poireau, E Prencipe, V Tisserand, J Garra Tico, E Grauges, M Martinelli, D. A. Milanes, A Palano [......] T. J. Gershon, P F Harrison, T E Latham, E. M. T. Puccio, H R Band, S Dasu, Y Pan, R Prepost, C. O. Vuosalo, S L Wu

  02/2011;

  Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-waveUsing a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).

• Biconnecting a Network of Mobile Robots Using Virtual Angular Forces

  Authors: A. Casteigts, J. Albert, S. Chaumette, A. Nayak, I. Stojmenović

  Vehicular Technology Conference Fall (VTC 2010-Fall), 2010 IEEE 72nd; 10/2010

  This paper proposes a new solution to the problem of self-deploying a network of wireless mobile robots with simultaneous consideration to several criteria, that are, the fault-toleranceThis paper proposes a new solution to the problem of self-deploying a network of wireless mobile robots with simultaneous consideration to several criteria, that are, the fault-tolerance (biconnectivity) of the resulting network, its coverage, its diameter, and the quantity of movement required to complete the deployment. These criteria have already been addressed individually in previous works, but we propose here an elegant solution to address all of them at once. Our approach is based on combining two complementary sets of virtual forces: spring forces, whose properties are well known to provide optimal coverage at reasonable movement cost, and angular forces, a new type of force proposed here whose effect is to rotate two angularly consecutive neighbors toward one another when the corresponding angle is larger than 60° (even if these nodes are not direct neighbors). Angular forces have the global effect of biconnecting the network and reducing its diameter, while not affecting the benefits obtained by spring forces on coverage. In this paper we give a detailed description of the combination of both types of forces. We also provide an implementation relying only on position exchanges within two hops. Simulations results are finally presented to evaluate our solution with respect to the four considered criteria (coverage, biconnectivity, quantity of movements, and diameter), and compare it with prior approaches.

• Search for f(J)(2220) in radiative J/ψ decays.

  Authors: P del Amo Sanchez, J P Lees, V Poireau, E Prencipe, V Tisserand, J Garra Tico, E Grauges, M Martinelli, A Palano, M Pappagallo [......] P F Harrison, T E Latham, E M T Puccio, H R Band, S Dasu, K T Flood, Y Pan, R Prepost, C O Vuosalo, S L Wu

  Physical review letters. 10/2010; 105(17):172001.

  We present a search for f(J)(2220) production in radiative J/ψ→γf(J)(2220) decays using 460  fb⁻¹ of data collected with the BABAR detector at the SLAC PEP-II e(+)e⁻ collider. The f(J)(2220) isWe present a search for f(J)(2220) production in radiative J/ψ→γf(J)(2220) decays using 460  fb⁻¹ of data collected with the BABAR detector at the SLAC PEP-II e(+)e⁻ collider. The f(J)(2220) is searched for in the decays to K(+)K⁻ and K(S)⁰K(S)⁰. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/ψ→γf(J)(2220) and f(J)(2220)→K(+)K⁻(K(S)⁰K(S)⁰) as a function of spin and helicity are set at the level of 10⁻⁵, below the central values reported by the Mark III experiment.