887 research outputs found
Observation of a Vector Charmoniumlike State at 4.7 GeV / and Search for in
No full textUsing data samples with an integrated luminosity of 5.85 fb(-1) collected at center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector operating at the BEPCII storage ring, we measure the cross section for the process e(+)e(-) -> K+ K- J/psi. A new resonance with a mass of M = 4708(-15)(+17) +/- 21 MeV/c(2) and a width of Gamma = 126(-23)(+27) +/-+/- 30 MeV is observed in the energy-dependent line shape of the e(+)e(-) -> K+ K- J/psi. cross section with a significance over 5 sigma. The K(+)J/psi system is also investigated to search for charged charmoniumlike states, but no significant Z(cs)(+) states are observed. Upper limits on the Born cross sections for e+e- -> K-Z(cs)(3985)(+)/K-Z(cs)(4000)(+) + c:c: with Z(cs)(3985)(+/-)/Z(cs)(4000)(+/-) -> K(+/-)J/psi are reported at 90% confidence levels. The ratio of branching fractions {[B(Z(cs)(3985)(+) -> K+J/psi)]/B[Z(cs)(3985)(+) -> ((D) over bar D-0(s)*(+) + (D) over bar*D-0(s)+)]} is measured to be less than 0.03 at 90% confidence level.LPH
Search for <i>X</i>(1870) via the decay <i>J</i>/ψ → ω<i>K</i><SUP>+</SUP><i>K</i><SUP>-</SUP>η
No full textUsing a sample of (10087 +/- 44) x 10(6) J/psi events collected by the BESIII detector at the BEPCII collider, we search for the decay X(1870) -> K+K-eta via the J/psi -> omega K+K-eta process for the first time. No significant X(1870) signal is observed. The upper limit on the branching fraction of the decay J/psi -> omega X(1870) -> omega K+K-eta is determined to be 9.55 x 10(-7) at the 90% confidence level. In addition, the branching faction B(J/psi -> omega K+K-eta) is measured to be (3.33 +/- 0.02(stat) +/- 0.12(syst) x 10(-4).LPHE-L
Improved measurements of D0 →K−l+νl andD+ →K ̄0l+νl
No full textUsing 7.93 fb(-1) of e(+)e(-) collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector, we measure the absolute branching fractions of D-0 -> K(-)e(+)nu(e), D-0 -> K- mu(+)nu(mu), D+ -> (K) over bar (0) e(+)nu(e), and D+ -> (K) over bar (0) mu(+)nu(mu) to be (3.521 +/- 0.009(stat) +/- 0.016(syst))%, (3.419 +/- 0.011(stat) +/- 0.016(syst))%, (8.864 +/- 0.039(stat) +/- 0.082s(yst))%, and (8.665 +/- 0.046(stat) +/- 0.084(syst) )%, respectively. By performing a simultaneous fit to the partial decay rates of these four decays, the product of the hadronic form factor f(+)(K) (0) and the modulus of the c -> s Cabibbo-Kobayashi-Maskawa matrix element |V-cs| is determined to be f(+)(K) (0) |V-cs| = 0.7171 +/- 0.0011(stat) +/- 0.0013(syst). Taking the value of |V-cs| = 0.97349 +/- 0.00016 from the standard model global fit or that of f(+)(K) (0) = 0.7452 +/- 0.0031 from the lattice quantum chromodynamics calculation as input, we derive the results f(+)(K) (0) =..
Measurements of K S 0 - K L 0 asymmetries in the decays Λ c + → p K L , S 0 , p K L , S 0 π + π − and p K L , S 0 π 0
No full textAbstract Using e + e − annihilation data sets corresponding to an integrated luminosity of 4.5 fb −1, collected with the BESIII detector at center-of-mass energies between 4.600 and 4.699 GeV, we report the first measurements of the absolute branching fractions B Λ c + → p K L 0 = (1.67 ± 0.06 ± 0.04)%, B Λ c + → p K L 0 π + π − = (1.69 ± 0.10 ± 0.05)%, and B Λ c + → p K L 0 π 0 = (2.02 ± 0.13 ± 0.05)%, where the first uncertainties are statistical and the second systematic. Combining with the known branching fractions of Λ c + → p K S 0 , Λ c + → p K S 0 π + π − , and Λ c + → p K S 0 π 0 , we present the first measurements of the K S 0 - K L 0 asymmetries R Λ c + K S , L 0 X = B Λ c + → K S 0 X − B Λ c + → K L 0 X B Λ c + → K S 0 X + B Λ c + → K L 0 X in charmed baryon decays: R Λ c + p K S , L 0 = − 0.025 ± 0.031 , R Λ c + p K S , L 0 π + π − = − 0.027 ± 0.048 and R Λ c + p K S , L 0 π 0 = − 0.015 ± 0.046 . No significant asymmetries with statistical significance are observed
Search for ηc (2S) →p p ¯ K+K- and measurement of χcJ →p p ¯ K+K- in ψ (3686) radiative decays
No full textA search for ηc(2S)→pp¯K+K-, together with measurement of branching fractions of χcJ(J=0,1,2)→pp¯K+K- in the ψ(3686)→γηc(2S) and the ψ(3686)→γχcJ radiative decays, is performed with (2712.4±14.3)×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider. An evidence for ηc(2S)→pp¯K+K- is found, with a significance of 3.3σ. The product branching fraction of B[ψ(3686)→γηc(2S)]·B[ηc(2S)→pp¯K+K-] is determined to be (1.98±0.41stat±0.99syst)×10-7. The product branching fractions of B[ψ(3686)→γχcJ]·B[χcJ→pp¯K+K-] are measured to be (2.49±0.03stat±0.15syst)×10-5, (1.83±0.02stat±0.11syst)×10-5, and (2.43±0.02stat±0.15syst)×10-5, for J=0, 1, and 2, respectively.LPHE-L
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Observation and study of the decay J /ψ →φηη′
No full textWe report the observation and study of the decay J/psi -> phi eta eta' phi eta eta' using 1.3 x 10(9) J/psi events collected with the BESIII detector. Its branching fraction, including all possible intermediate states, is measured to be (2.32 +/- 0.06 +/- 0.16) x 10(-4). We also report evidence for a structure, denoted as X, in the phi eta' mass spectrum in the 2.0-2.1 GeV/c(2) region. Using two decay modes of the eta' meson (gamma pi(+)pi(-) and eta pi(+)pi(-)), a simultaneous fit to the Ore mass spectra is performed. Assuming the quantum numbers of the X to be J(P) = 1(-), its significance is found to be 4.4 sigma, with a mass and width of (2002.1 +/- 27.5 +/- 21.4) MeV/c(2) and (129 +/- 17 +/- 9) MeV, respectively, and a product branching fraction B(J/psi -> eta X) x B(X -> phi eta') = (9.8 +/- 1.2 +/- 1.7) x 10(-5). Alternatively, assuming J(P) = 1(+), the significance is 3.8 sigma, with a mass and width of (2062.8 +/- 13.1 +/- 7.2) MeV/c(2) and (177 +/- 36 +/- 35) MeV, respectively, and a product branching fraction B(J/psi -> eta X)x B(X -> phi eta') = (9.6 +/- 1.4 +/- 2.0) x 10(-5). The angular distribution of J/psi -> eta X is studied and the two J(P) assumptions of the X cannot be clearly distinguished due to the limited statistics. In all measurements the first uncertainties are statistical and the second systematic
Intelligent information mining from veterinary clinical records and open source repository
No full textThis paper reports an implementation of an intelligent mining approach from veterinary clinical records and an external source of information. The system retrieves information from a local veterinary clinical database and then complements this information with related records from an external source, OAIster. It utilizes text-mining, web service technologies and domain knowledge, in order to extract keywords, to retrieve related records from an external source, and to filter the extracted keywords list. This study meets a practical challenge encountered at the School of Veterinary and Biomedical Sciences at Murdoch University. The results indicate that the system can be used to increase the limited knowledge within a local source by complementing it with related records from an external source. Moreover, the system also reduces information overload by only retrieving a set of related information from an external source. Finally, domain knowledge can be used to filter the extracted keywords, in this case, selected medical keywords from the extracted keyword list
Observation of X<sub>cJ</sub> →3( K<SUP>+</SUP> K<SUP>-</SUP> )
No full textBy analyzing (27.12 +/- 0.14) x 10(8) Psi(3686) events collected with the BESIII detector operating at the BEPCII collider, the decay processes X-cJ -> 3( K+ K- ) (J = 0, 1, 2) are observed for the first time with statistical significances of 8.2 sigma, 8.1 sigma, and 12.4 sigma, respectively. The product branching fractions of Psi(3686) -> gamma X-cJ , X-cJ -> 3( K+ K- ) are presented and the branching fractions of X-cJ -> 3( K+ K- ) decays are determined to be B-Xc0 -> 3( K+ K- ) = (10.7 +/- 1.8 +/- 1.1) x 10(-6), B-Xc1 -> 3( K+ K- ) = (4.2 +/- 0.9 +/- 0.5) x 10(-6), and B-Xc2 -> 3( K+ K- ) 1/4 (7.2 +/- 1.1 +/- 0.8) x 10(-6), where the first uncertainties are statistical and the second are systematic.LPHE-L
Nanomaterials for energy storage
No full textThe results presented in this thesis demonstrate the first synthesis of several nanostructured transition metal oxides and lithium containing transition metal oxides. Their uses in lithium-ion batteries and/or as magnetic materials have been investigated.
The first example of two and three dimensional mesoporous Fe₂O₃ has been prepared by using the soft templating (surfactant) method. The materials have amorphous walls and exhibit superparamagnetic behaviour.
By using a hard template route, a mesoporous α-Fe₂O₃ with highly crystalline walls has been synthesized. Its unique magnetic behaviour, distinct from bulk α-Fe₂O₃, nanoparticulate α-Fe₂O₃, and mesoporous Fe₂O₃ with disordered walls, has been demonstrated.
The hard template method was also used to prepare nanowire and mesoporous Co₃O₄, β-MnO₂ and MnO₃ with crystalline walls. Their electrochemical properties as electrodes in Li-ion batteries have been investigated. Mesoporous β-MnO₂ can accommodate 0.9 Li/Mn in stark contrast to bulk β-MnO₂ which cannot accommodate Li.
To prepare mesoporous materials which cannot be obtained directly by the hard template method, a post-templating route has been developed. Mesoporous Fe₃O₄, γ-Fe₂O₃, and Mn3O4 with ordered mesostructures and highly crystalline walls have been obtained by post-synthesis reduction/oxidation treatments. All the materials show unique magnetic properties compared with nanoparticulate and bulk materials.
Also, the first example of lithium containing mesoporous material, LT-LiCoO₂, was synthesized by first preparing mesoporous Co₃O₄, then reacting this with LiOH to form LT-LiCoO₂, with retention of the ordered nanostructure. The nanostructured LT-LiCoO₂ compounds demonstrate superior performance compared with normal or nanoparticulate LT-LiCoO₂, when used as intercalation electrodes in lithium batteries.
Finally, monodispersed Mn₃O₄ nanoparticles (diameter ~ 8 nm) with a core-shell structure (a highly crystalline Mn₃O₄ core encased in a thin MnO₂ shell) have been prepared for the first time. Ordered three-dimensional arrays form by spontaneous self-assembly. Magnetic measurements demonstrated that the self-assembled three-dimensional arrays exhibit spin-glass behaviour, rather than the anticipated superparamagnetic behaviour for isolated nanoparticles. Such behaviour is interpreted as arising from strong interactions between the core (crystallized Mn₃O₄) and shell (MnO₂)
Observation of ψ(3686) → Ω(-)K(+) Ξ 0 + c.c.
No full textUsing (27.12 +/- 0.14) x 10(8) ψ(3686) events collected with the BESIII detector at BEPCII, the decay of ψ(3686) -> Ω(-)K(+) Ξ 0 + c.c. is observed for the first time. The branching fraction of this decay is measured to be B-Psi(3686)->Omega K--(+)Xi(0)+c.c. = (2.78 +/- 0.40 +/- 0.18) x 10(-6), where the first uncertainty is statistical and the second is systematic. Possible baryon excited states are searched for in this decay, but no evident intermediate state is observed with the current sample size.LPH
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