Observation of Z_{b}(10610) and Z_{b}(10650) Decaying to B Mesons.

We report the analysis of the three-body e^{+}e^{-}→BB[over ¯]π^{±}, BB[over ¯]^{*}π^{±}, and B^{*}B[over ¯]^{*}π^{±} processes, including the first observations of the Z_{b}^{±}(10610)→[BB[over ¯]^{*}+c.c.]^{±} and Z_{b}^{±}(10650)→[B^{*}B[over ¯]^{*}]^{±} transitions that are found to dominate the corresponding final states. We measure Born cross sections for the three-body production of σ(e^{+}e^{-}→[BB[over ¯]^{*}+c.c.]^{±}π^{∓})=[17.4±1.6(stat)±1.9(syst)] pb and σ(e^{+}e^{-}→[B^{*}B[over ¯]^{*}]^{±}π^{∓})=[8.75±1.15(stat)±1.04(syst)] pb and set a 90% C.L. upper limit of σ(e^{+}e^{-}→[BB[over ¯]]^{±}π^{∓})<2.9 pb. The results are based on a 121.4 fb^{-1} data sample collected with the Belle detector at a center-of-mass energy near the ϒ(10860) peak.

Observation of the Decay B_{s}

We measure the decay B_{s}^{0}→K^{0}K[over ¯]^{0} using data collected at the ϒ(5S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. The data sample used corresponds to an integrated luminosity of 121.4 fb^{-1}. We measure a branching fraction B(B_{s}^{0}→K^{0}K[over ¯]^{0})=[19.6_{-5.1}^{+5.8}(stat)±1.0(syst)±2.0(N_{B_{s}^{0}B[over ¯]_{s}^{0}})]×10^{-6} with a significance of 5.1 standard deviations. This measurement constitutes the first observation of this decay.

Observation of B

We report the first observation of the decays B^{0}→pΛ[over ¯]D^{(*)-}. The data sample of 711 fb^{-1} used in this analysis corresponds to 772×10^{6} BB[over ¯] pairs, collected at the ϒ(4S) resonance by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We observe 19.8σ and 10.8σ excesses of events for the two decay modes and measure the branching fractions of B^{0}→pΛ[over ¯]D^{-} and B^{0}→pΛ[over ¯]D^{*-} to be (25.1±2.6±3.5)×10^{-6} and (33.6±6.3±4.4)×10^{-6}, respectively, where the first uncertainties are statistical and the second are systematic. These results are not compatible with the predictions based on the generalized factorization approach. In addition, a threshold enhancement in the dibaryon (pΛ[over ¯]) system is observed, consistent with that observed in similar B decays.

First Observation of the Hadronic Transition ϒ(4S)→ηh(b)(1P) and New Measurement of the h(b)(1P) and η(b)(1S) Parameters.

Using a sample of 771.6×10(6) ϒϒ(4S) decays collected by the Belle experiment at the KEKB e(+)e(-) collider, we observe, for the first time, the transition ϒ(4S)→ηh(b)(1P) with the branching fraction B[ϒ(4S)→ηh(b)(1P)]=(2.18±0.11±0.18)×10(-3) and we measure the h(b)(1P) mass M(h(b)(1P))=(9899.3±0.4±1.0) MeV/c(2), corresponding to the hyperfine (HF) splitting ΔM(HF)(1P)=(0.6±0.4±1.0) MeV/c(2). Using the transition h(b)(1P)→γη(b)(1S), we measure the η(b)(1S) mass M(η(b)(1S))=(9400.7±1.7±1.6) MeV/c(2), corresponding to ΔM(HF)(1S)=(59.6±1.7±1.6) MeV/c(2), the η(b)(1S) width Γ(η(b)(1S))=(8(-5)(+6)±5) MeV/c(2) and the branching fraction B[h(b)(1P)→γη(b)(1S)]=(56±8±4)%.

First Observation of CP Violation in B[over ¯]

We report a measurement of the time-dependent CP asymmetry of B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays, where the light neutral hadron h^{0} is a π^{0}, η, or ω meson, and the neutral D meson is reconstructed in the CP eigenstates K^{+}K^{-}, K_{S}^{0}π^{0}, or K_{S}^{0}ω. The measurement is performed combining the final data samples collected at the ϒ(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6} BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6} BB[over ¯] pairs recorded by the Belle detector. We measure the CP asymmetry parameters -η_{f}S=+0.66±0.10(stat)±0.06(syst) and C=-0.02±0.07(stat)±0.03(syst). These results correspond to the first observation of CP violation in B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations.

Measurement of the Direct CP Asymmetry in B¯â†’X(s+dγ) Decays with a Lepton Tag.

We report the measurement of the direct CP asymmetry in the radiative B¯â†’X(s+dγ) decay using a data sample of (772 ± 11)×10(6) BB[over ¯] pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The CP asymmetry is measured as a function of the photon energy threshold. For Eγ*≥2.1 GeV, where Eγ* is the photon energy in the center-of-mass frame, we obtain A(CP)(B¯â†’X(s+dγ))=(2.2±3.9±0.9)%, consistent with the standard model prediction.

Observation of e+e- → π+π-π(0)(χbJ) and Search for X(b) → ωϒ(1S) at sqrt[s] = 10.867 GeV.

The e(+)e(-) → π(+)π(-)π(0)χ(bJ) (J = 0,1,2) processes are studied using a 118 fb(-1) data sample acquired with the Belle detector at a center-of-mass energy of 10.867 GeV. Unambiguous π(+)π(-)π(0)χ(bJ) (J = 1,2), ωχ(b1) signals are observed, and indication for ωχ(b2) is seen, both for the first time, and the corresponding cross section measurements are presented. No significant π(+)π(-)π(0)χ(b0) or ωχ(b0) signals are observed, and 90% confidence level upper limits on the cross sections for these two processes are obtained. In the π(+)π(-)π(0) invariant mass spectrum, significant non-ω signals are also observed. We search for the X(3872)-like state (named X(b)) decaying into ωϒ(1S); no significant signal is observed with a mass between 10.55 and 10.65 GeV/c(2).

[Pulmonary rehabilitation and non-invasive ventilation before lung surgery in very high-risk patients]. / Réhabilitation et VNI avant exérèse pulmonaire chez les patients à haut risque opératoire.

INTRODUCTION: The benefits of a rehabilitation program before surgical lung cancer resection remain to be defined. The purpose of this prospective observational study was to assess the effects of rehabilitation together with the use of noninvasive ventilation (NIV) in patients who were at a high operative risk. METHODS: Between January 2010 and June 2011, 20 consecutive patients (16 males, four females, mean age: 66 years [44-79]) with a clinical N0 non-small cell lung cancer were included. Eligibility criteria were predicted post-operative respiratory function (FEV1, VO2 max) below the guideline thresholds for eligibility for surgical resection and/or associated with severe co-morbidities. The protocol included a cardiorespiratory rehabilitation program and 3 hours of NIV each day. Functional tests were repeated after 3 weeks of therapy. RESULTS: Participants displayed a significant increase in their FEV1 and VO2 max, which allowed surgical resection to go ahead in all patients (lobectomy, n=15; pneumonectomy, n=3; bilobectomy, n=2). The morbidity rate was 20% (acute renal failure, n=2; pneumonia, n=1; haemothorax, n=1). The mortality rate was 5% (myocardial infarction, n=1). Further postoperative rehabilitation allowed a return at home in 19 patients after a mean hospital stay of 11 days. CONCLUSION: Pulmonary rehabilitation associated with a period of preoperative NIV allows surgery to be performed in patients who are not initially eligible for resection. An evaluation of long-term outcomes survival in comparison to non-surgical therapies is necessary.

Determination of the strange-quark density of the proton from ATLAS measurements of the W→ℓν and Z→ℓℓ cross sections.

A QCD analysis is reported of ATLAS data on inclusive W(±) and Z boson production in pp collisions at the LHC, jointly with ep deep-inelastic scattering data from HERA. The ATLAS data exhibit sensitivity to the light quark sea composition and magnitude at Bjorken x∼0.01. Specifically, the data support the hypothesis of a symmetric composition of the light quark sea at low x. The ratio of the strange-to-down sea quark distributions is determined to be 1.00(-0.28)(+0.25) at absolute four-momentum transfer squared Q(2)=1.9 GeV(2) and x=0.023.

Search for tb resonances in proton-proton collisions at √s=7 TeV with the ATLAS detector.

This Letter presents a search for tb resonances in 1.04 fb(-1) of LHC proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 7 TeV. Events with a lepton, missing transverse momentum, and two jets are selected and the invariant mass of the corresponding final state is reconstructed. The search exploits the shape of the tb invariant mass distribution compared to the expected standard model backgrounds. The model of a right-handed W(R)' with standard model-like couplings is chosen as the benchmark model for this search. No statistically significant excess of events is observed in the data, and upper limits on the cross section times the branching ratio of W(R)' resonances at 95% C.L. lie in the range of 6.1-1.0 pb for W(R)' masses ranging from 0.5 to 2.0 TeV. These limits are translated into a lower bound on the allowed right-handed W(R)' mass, giving m(W(R)'))>1.13 TeV at 95% C.L.

Search for production of resonant states in the photon-jet mass distribution using pp collisions at √s=7 TeV collected by the ATLAS detector.

This Letter describes a model-independent search for the production of new resonant states in photon+jet events in 2.11 fb(-1) of proton-proton collisions at √s=7 TeV. We compare the photon+jet mass distribution to a background model derived from data and find consistency with the background-only hypothesis. Given the lack of evidence for a signal, we set 95% credibility level limits on generic Gaussian-shaped signals and on a benchmark excited-quark (q*) model, excluding 2 TeV Gaussian resonances with cross section times branching fraction times acceptance times efficiency near 5 fb and excluding q* masses below 2.46 TeV, respectively.

Observation of spin correlation in tt¯ events from pp collisions at √s=7 TeV using the ATLAS detector.

A measurement of spin correlation in tt[over ¯] production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb(-1). Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to A(helicity)=0.40(-0.08)(+0.09), in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations.

Search for gluinos in events with two same-sign leptons, jets, and missing transverse momentum with the ATLAS detector in pp collisions at sqrt[s]=7 TeV.

A search is presented for gluinos decaying via the supersymmetric partner of the top quark using events with two same-sign leptons, jets, and missing transverse momentum. The analysis is performed with 2.05 fb(-1) of integrated luminosity from pp collisions at sqrt[s]=7 TeV collected by the ATLAS detector at the LHC. No excess beyond the standard model expectation is observed, and exclusion limits are derived for simplified models where the gluino decays via the supersymmetric partner of the top quark and in the minimal supergravity and constrained minimal supersymmetric standard model framework. In those scenarios, gluino masses below 550 GeV are excluded at 95% C.L. within the parameter space considered, significantly extending the coverage with respect to existing limits. Depending on the model parameters, gluino masses up to 750 GeV can also be excluded at 95% C.L.

Search for a light Higgs boson decaying to long-lived weakly interacting particles in proton-proton collisions at sqrt[s] = 7 TeV with the ATLAS detector.

A search for the decay of a light Higgs boson (120-140 GeV) to a pair of weakly interacting, long-lived particles in 1.94 fb(-1) of proton-proton collisions at sqrt[s] = 7 TeV recorded in 2011 by the ATLAS detector is presented. The search strategy requires that both long-lived particles decay inside the muon spectrometer. No excess of events is observed above the expected background and limits on the Higgs boson production times branching ratio to weakly interacting, long-lived particles are derived as a function of the particle proper decay length.

Search for pair production of a heavy up-type quark decaying to a W boson and a b quark in the lepton + jets channel with the ATLAS detector.

A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t't[over ¯]'→W(+)bW(-)b[over ¯]. The search is based on 1.04 fb(-1) of proton-proton collisions at √[s]=7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum, and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit of 404 GeV is set for the mass of the t' quark.

Search for pair production of a new b' quark that decays into a Z boson and a bottom quark with the ATLAS detector.

A search is reported for the pair production of a new quark b' with at least one b' decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb(-1) of integrated luminosity, were collected from pp collisions at √s = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b' candidates is tested for an enhancement. No evidence for a b' signal is detected in the observed mass distribution, resulting in the exclusion at a 95% confidence level of b' quarks with masses m (b') < 400 GeV that decay entirely via b' → Z+b. In the case of a vectorlike singlet b' mixing solely with the third standard model generation, masses m(b') < 358 GeV are excluded.

Search for down-type fourth generation quarks with the ATLAS detector in events with one lepton and hadronically decaying W bosons.

This Letter presents a search for pair production of heavy down-type quarks decaying via b' → Wt in the lepton + jets channel, as b'b' → W- tW+ t → bbW+ W- W+ W- → l± νbbqqqqqq. In addition to requiring exactly one lepton, large missing transverse momentum, and at least six jets, the invariant mass of nearby jet pairs is used to identify high transverse momentum W bosons. In data corresponding to an integrated luminosity of 1.04 fb(-1) from pp collisions at sqrt[s] = 7 TeV recorded with the ATLAS detector, a heavy down-type quark with mass less than 480 GeV can be excluded at the 95% confidence level.

Search for scalar bottom quark pair production with the ATLAS detector in pp collisions at sqrt[s]=7 TeV.

The results of a search for pair production of the scalar partners of bottom quarks in 2.05 fb(-1) of pp collisions at sqrt[s]=7 TeV using the ATLAS experiment are reported. Scalar bottom quarks are searched for in events with large missing transverse momentum and two jets in the final state, where both jets are identified as originating from a bottom quark. In an R-parity conserving minimal supersymmetric scenario, assuming that the scalar bottom quark decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits are obtained in the b(1) - χ(1)(0) mass plane such that for neutralino masses below 60 GeV scalar bottom masses up to 390 GeV are excluded.

Observation of a new χ(b) state in radiative transitions to Υ(1S) and Υ(2S) at ATLAS.

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 an integrated luminosity of 4.4 fb(-1), these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ â†’ 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 decay channel in pp collisions at √s=7 TeV with the ATLAS detector.

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 √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