1,723 research outputs found

    Branching ratios, CPCP asymmetries and polarizations of Bψ(2S)VB\rightarrow \psi(2S) V decays

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    We analyzed the nonleptonic decays B/Bsψ(2S)VB/B_s\to \psi(2S) V with V=(ρ,ω,K,ϕ)V=(\rho, \omega, K^{*}, \phi) by employing the perturbative QCD (PQCD) factorization approach. Here the branching ratios, the CPCP asymmetries and the complete set of polarization observables are investigated systematically. Besides the traditional contributions from the factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order (NLO) vertex corrections could also provide considerable contributions. The PQCD predictions for the branching ratios of the B(s)ψ(2S)K,ψ(2S)ϕB_{(s)}\to \psi(2S)K^{*}, \psi(2S) \phi decays are consistent with the measured values within errors. As for Bψ(2S)ρ,ψ(2S)ωB\to \psi(2S) \rho, \psi(2S) \omega decays, the branching ratios can reach the order of 10510^{-5} and could be measured in the LHCb and Belle-II experiments. The numerical results show that the direct CPCP asymmetries of the considered decays are very small. Thus the observation of any large direct CPCP asymmetry for these decays will be a signal for new physics. The mixing induced CPCP asymmetries in the neutral modes are very close to sin2β(s)\sin 2\beta_{(s)}, which suggests that these channels can give a cross-check on the measurement of the Cabbibo-Kobayashi-Maskawa (CKM) angle β\beta and βs\beta_s. We found that the longitudinal polarization fractions f0f_0 are suppressed to 50%\sim 50\% due to the large nonfactorizable contributions. The magnitudes and phases of the two transverse amplitudes A\mathcal {A}_{\parallel} and A\mathcal {A}_{\perp} are roughly equal, which is an indication for the approximate light quark helicity conservation in these decays. The overall polarization observables of Bψ(2S)K0B\to \psi(2S) K^{*0} and Bsψ(2S)ϕB_s\to \psi(2S) \phi channels are also in good agreement with the experimental measurements as reported by LHCb and BaBar. Other results can also be tested by the LHCb and Belle-II experiments.Comment: 14 pages, 1 figure, 6 table

    Preparation and In Vitro Drug Release Behavior of 1,10-Phenanthroline/β-cyclodextrin–poly (Glycidyl Methacrylate) Drug-Loaded Microspheres

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    In this study, novel star-shaped polymers of β-cyclodextrin (β-CD)–poly (glycidyl methacrylate) (PGMA) were prepared by atom transfer radical polymerization (ATRP), formed from GMA and β-CD. In addition, the structure, properties and hydrophilicity of the β-CD-PGMA polymers thus prepared were systematically analyzed. 1,10-phenanthroline monohydrate (Phen)/β-CD-PGMA drug-loaded microspheres were prepared by emulsion solvent evaporation. The optimum preparation conditions were determined by orthogonal tests. Analysis results indicated that the performance of star-shaped polymers of β-CD-PGMA clearly changes, resulting in the increase of the contact angle from 17° to 72.5°, and their thermal degradation temperature was enhanced from 260 °C to 401 °C. Moreover, β-CD-PGMA drug-loaded microspheres with a smooth, spherical surface were successfully prepared, and the drug-loading capacity and average particle size of drug-loaded microspheres were 26.67 % and 10 μm, respectively. Drug release tests indicated that the release behavior of β-CD-PGMA drug-loaded microspheres conformed to Higuchi release kinetics, which exhibited a significant drug delivery capability. The release rate and utilization of β-CD-PGMA were greater than that of β-CD, demonstrating that β-CD-PGMA was more suitable as a drug delivery material

    Electron self-energy and effective mass in a single heterostructure

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    In this paper, we investigate the electron self-energy and effective mass in a single heterostructure using Green-function method. Numerical calculations of the electron self-energy and effective mass for GaAs/AlAs heterostructure are performed. The results show that the self energy (effective mass) of electron, which incorporate the energy of electron coupling to interface-optical phonons and half three-dimension LO phonons, monotonically increase(decrease) from that of interface polaron to that of 3D bulk polaron with the increase of the distance between the position of the electron and interface.Comment: 10 pages, 2 figure

    Quasi-two-body decays Bηc(1S,2S)  [ρ(770),ρ(1450),ρ(1700)]  ππB \to \eta_c {(1S ,2S)}\;[\rho(770),\rho(1450),\rho(1700) \to ]\; \pi\pi in the perturbative QCD approach

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    In this paper, we calculated the branching ratios of the quasi-two-body decays Bηc(1S,2S)B \to \eta_c (1S ,2S) [ρ(770),ρ(1450),ρ(1700)]ππ[\rho(770), \rho(1450),\rho(1700)\to ] \pi\pi by employing the perturbative QCD (PQCD) approach. The contributions from the PP-wave resonances ρ(770)\rho(770), ρ(1450)\rho(1450) and ρ(1700)\rho(1700) were taken into account. The two-pion distribution amplitude ΦππP\Phi_{\pi\pi}^{\rm P} is parameterized by the vector current time-like form factor FπF_{\pi} to study the considered decay modes. We found that (a) the PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the order of 10710610^{-7} \sim 10^{-6}, while the two-body decay rates B(Bηc(1S,2S)(ρ(1450),ρ(1700))){\cal B}(B \to \eta_c{(1S,2S)} (\rho(1450),\rho(1700))) are extracted from those for the corresponding quasi-two-body decays; (b) the whole pattern of the pion form factor-squared Fπ2|F_\pi|^2 measured by the BABAR Collaboration could be understood based on our theoretical results; (c) the general expectation based on the similarity between BηcππB \to \eta_c \pi\pi and BJ/ψππB \to J/\psi \pi\pi decays are confirmed: R2(ηc)0.45R_2(\eta_c)\approx 0.45 is consistent with the measured R2(J/ψ)0.56±0.09R_2(J/\psi)\approx 0.56\pm 0.09 within errors; and (d) new ratios R3(ηc(1S))R_3(\eta_c(1S)) and R4(ηc(2S))R_4(\eta_c(2S)) among the branching ratios of the considered decay modes are defined and could be tested by future experiments.Comment: 10 pages, 3 figure

    Quasi-two-body decays BDK(892)DKπB \to D K^*(892) \to D K \pi in the perturbative QCD approach

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    We study the quasi-two-body decays BDK(892)DKπB\to D K^*(892) \to D K\pi by employing the perturbative QCD approach. The two-meson distribution amplitudes \Phi_{K\pi}^{\text{P-wave}} are adopted to describe the final state interactions of the kaon-pion pair in the resonance region. The resonance line shape for the PP-wave KπK\pi component K(892)K^*(892) in the time-like form factor FKπ(s)F_{K\pi}(s) is parameterized by the relativistic Breit-Wigner function. For most considered decay modes, the theoretical predictions for their branching ratios are consistent with currently available experimental measurements within errors. We also disscuss some ratios of the branching fractions of the concerned decay processes. More precise data from LHCb and Belle-II are expected to test our predictions.Comment: 10 pages, 3 figures and 2 tables.To be published in EPJ

    Observation and management of shallow anterior chamber after glaucoma surgery

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    AIM: To analyze the cause and management of shallow anterior chamber after glaucoma surgery.<p>METHODS: The cause and management of shallow anterior chamber after glaucoma surgery on 298 cases(462 eyes)were analyzed retrospectively.<p>RESULTS: In 298 cases(462 eyes), 99 eyes(21.4%)had shallow anterior chamber. In 358 eyes treated with trabeculectomy, 77 eyes(21.5%)had shallow anterior chamber. In 85 eyes treated with trabeculectomy+MMC(mitomycin C), 20 eyes(23.5%)had shallow anterior chamber. In 19 eyes treated with trabeculectomy combined with cataract phacoemulsification and intraocular lens implantation, 2 eyes(10.53%)had shallow anterior chamber. Shallow anterior chamber appeared at 1 day to 5 days postoperatively. Forty-two eyes(42.4%)were with excessive filtering, 6 eyes(6.1%)with malignant glaucoma, 29 eyes(29.3%)with choroidal detachment, 2 eyes(2.0%)with malignant glaucoma complicated by choroidal detachment. Of 99 eyes with shallow anterior chamber, anterior chamber of 79 eyes recovered treated by nonsurgical methods, 20 eyes treated by operation.<p>CONCLUSION: The common cause of shallow anterior chamber after glaucoma surgery was preoperative high intraocular pressure, inflammation, excessive filtering, conjunctival flap flushing and choroidal detachment. Most cases can be managed with nonsurgical methods. Surgical interference should be taken if necessary

    Probing dark particles indirectly at the CEPC

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    When dark matter candidate and its parent particles are nearly degenerate, it would be difficult to probe them at the Large Hadron Collider directly. We propose to explore their quantum loop effects at the CEPC through the golden channel process e+eμ+μe^+e^-\to \mu^+\mu^-. We use a renormalizable toy model consisting of a new scalar and a fermion to describe new physics beyond the Standard Model. The new scalar and fermion are general multiplets of the SU(2)L×U(1)YSU(2)_L\times U(1)_Y symmetry, and couple to the muon lepton through Yukawa interaction. We calculate their loop contributions to anomalous γμ+μ\gamma\mu^+\mu^- and Zμ+μZ\mu^+\mu^- couplings which can be applied to many new physics models. The prospects of their effects at the CEPC are also examined assuming a 0.002 accuracy in the cross section measurement
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