Using 567 pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrts=4.599 GeV, near the Λ_{c}^{+}Λover ¯_{c}^{-} threshold, we study the singly Cabibbo-suppressed ...decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})=(6.70±0.48±0.25)%, B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})=(1.81±0.33±0.13)%, and B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Using 1310.6 x 106 J/ψ and 448.1 x 106 ψ(3686) events collected with the BESIII detector, the branching fractions of J/ψ decays to $Σ^+\overline{Σ}^-$ is measured to be (10.61 ± 0.04 ± 0.36) x 10-4, ...which is significantly more precise than the current world average. The branching fractions of ψ(3686) decays to $Σ^+\overline{Σ}^-$ is measured to be (2.52 ± 0.04 ± 0.09) x 10-4, which is consistent with the previous measurements. In addition, the ratio of $\mathcal{B}$(ψ(3686) → $Σ^+\overline{Σ}^-$)/$\mathcal{B}$(J/ψ → $Σ^+\overline{Σ}^-$) is determined to be (23.8 ± 1.1)% which violates the “12% rule”.
Using a data set corresponding to an integrated luminosity of 6.32 fb–1 recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the decay ...$D_s^{+}$ → $π^+π^0π^0$ is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $D_s^{+}$ → $π^+π^0π^0$ is measured to be (0.50 ± 0.04stat ± 0.02syst)%. The absolute branching fraction of the intermediate process $D_s^{+}$ → $f_o$(980)$π^+$, $f_o$(980) → $π^oπ^o$ is determined to be (0.28 ± 0.04stat ± 0.04syst)%.
To investigate the effects of different target plasma remifentanil concentrations on the minimum alveolar concentration of sevoflurane (MAC) for blocking adrenergic response (BAR) during laparoscopic ...gynaecological surgery with carbon dioxide insufflation.
Seventy-five gynaecological patients with ASA I–II undergoing laparoscopic surgery were randomly assigned to three groups. Anaesthesia was induced by sevoflurane, and 0.1 mg kg−1 of vecuronium i.v. was injected to facilitate tracheal intubation. After intubation the target plasma concentrations of remifentanil in Groups 1, 2, and 3 were adjusted to 0, 1, and 2 ng ml−1, respectively. The changes in haemodynamics were observed before and after the creation of carbon dioxide pneumoperitoneum. The MAC BAR of sevoflurane in each group was determined by using an up-and-down sequential-allocation technique, and blood samples were collected at corresponding time points to determine the concentrations of remifentanil, norepinephrine, and epinephrine.
In Groups 1, 2 and 3, the MAC BAR of sevoflurane was 4.6% (CI 95%: 4.3–4.9%), 2.4% (CI 95%: 2.2–2.6%), and 1.7% (CI 95%: 1.4–2.1%), respectively. No significant differences were found in the increase of norepinephrine, epinephrine, and mean arterial pressure after compared with before insufflation of pneumoperitoneum among the three groups.
Remifentanil can effectively decrease the sevoflurane concentration to block sympathetic adrenergic response to CO2 pneumoperitoneum stimulus. At similar MAC BAR the haemodynamic and adrenergic response is not affected by the infused remifentanil concentration.
The number of this clinical trial registry is ChiCTR-TRC-13004005, and the Universal Trial Number is U1111-1151-5630.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A search for the hadronic decays of the $h_c$ meson to the final states $p\overline{p}π^+π^-π^o$, $p\overline{p}η$, and $p\overline{p}π^o$ via the process $\psi$(3686) → $π^oh_c$ is performed using ...(4.48 ± 0.03) x 108 $\psi$(3686) events collected with the BESIII detector. The decay channel $h_c$ → $p\overline{p}η$ is observed for the first time with a significance greater than 5σ and a branching fraction of (6.41 ± 1.74 ± 0.53 ± 1.00) x 10-4, where the uncertainties are statistical, systematic, and that from the branching fraction of $\psi$(3686) → $π^oh_c$. Strong evidence for the decay $h_c$ → $p\overline{p}π^+π^-π^o$ is found with a significance of 4.9σ and a branching fraction of (3.84 ± 0.83 ± 0.69 ± 0.58) x 10-3. The significances include systematic uncertainties. No clear signal of the decay $h_c$ → $p\overline{p}π^o$ is found, and an upper limit of 6.59 x 10-4 on its branching fraction is set at the 90% confidence level.
We search for J / ψ radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J / ψ produced through the process ψ ( 3686 ) → π + π − J / ψ in a data sample ...of ( 448.1 ± 2.9 ) × 10 6 ψ ( 3686 ) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2 GeV / c 2 . The upper limit corresponding to an invisible particle with zero mass is 7.0 × 10 −7 at the 90% confidence level.
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Mirror‐mode structures are widely observed in space plasma environments. Although plasma features within the structures have been extensively investigated in theoretical models and numerical ...simulations, relatively few observational studies have been made, due to a lack of high‐cadence measurements of particle distributions in previous space missions. In this work, electron dynamics associated with mirror‐mode structures are studied based on Magnetospheric Multiscale observations of electron pitch angle distributions. We define mirror‐mode peaks/troughs as the region where the magnetic field strength is greater/smaller than the mean field. The observations show that most electrons are trapped inside the mirror‐mode troughs and display a donut‐like pitch angle distribution configuration. Besides the trapped electrons in mirror‐mode troughs, we find that electrons are also trapped between ambient mirror‐mode peaks and coexisting untrapped electrons within the mirror‐mode structure. Analysis shows that the observed donut‐like electron distributions are the result of betatron cooling and the spatial dependence of electron pitch angles within the structure.
Key Points
Electron PADs of magnetosheath mirror modes are observed by MMS
The PADs display a characteristic donut‐like configuration
Betatron cooling and spatial dependence of electron pitch angle are able to produce such a distribution
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK