623 research outputs found

    Barley plasma membrane intrinsic proteins (PIP aquaporins) as water and CO2 transporters

    Get PDF
    We identified barley aquaporins and demonstrated that one, HvPIP2;1, transports water and CO2. Regarding water homeostasis in plants, regulations of aquaporin expression were observed in many plants under several environmental stresses. Under salt stress, a number of plasma membrane-type aquaporins were down-regulated, which can prevent continuous dehydration resulting in cell death. The leaves of transgenic rice plants that expressed the largest amount of HvPIP2;1 showed a 40% increase in internal CO2 conductance compared with leaves of wild-type rice plants. The rate of CO2 assimilation also increased in the transgenic plants. The goal of our plant aquaporin research is to determine the key aquaporin species responsible for water and CO2 transport, and to improve plant water relations, stress tolerance, CO2 uptake or assimilation, and plant productivity via molecular breeding of aquaporins.</p

    Observation of ηcωω\eta_c\to\omega\omega in J/ψγωωJ/\psi\to\gamma\omega\omega

    Get PDF
    Using a sample of (1310.6±7.0)×106(1310.6\pm7.0)\times10^6 J/ψJ/\psi events recorded with the BESIII detector at the symmetric electron positron collider BEPCII, we report the observation of the decay of the (11S0)(1^1 S_0) charmonium state ηc\eta_c into a pair of ω\omega mesons in the process J/ψγωωJ/\psi\to\gamma\omega\omega. The branching fraction is measured for the first time to be B(ηcωω)=(2.88±0.10±0.46±0.68)×103\mathcal{B}(\eta_c\to\omega\omega)= (2.88\pm0.10\pm0.46\pm0.68)\times10^{-3}, where the first uncertainty is statistical, the second systematic and the third is from the uncertainty of B(J/ψγηc)\mathcal{B}(J/\psi\to\gamma\eta_c). The mass and width of the ηc\eta_c are determined as M=(2985.9±0.7±2.1)M=(2985.9\pm0.7\pm2.1)\,MeV/c2c^2 and Γ=(33.8±1.6±4.1)\Gamma=(33.8\pm1.6\pm4.1)\,MeV.Comment: 13 pages, 6 figure

    Search for the decay J/ψγ+invisibleJ/\psi\to\gamma + \rm {invisible}

    Full text link
    We search for J/ψJ/\psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψJ/\psi produced through the process ψ(3686)π+πJ/ψ\psi(3686)\to\pi^+\pi^-J/\psi in a data sample of (448.1±2.9)×106(448.1\pm2.9)\times 10^6 ψ(3686)\psi(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/c2\mathrm{\ Ge\kern -0.1em V}/c^2. The upper limit corresponding to an invisible particle with zero mass is 7.0×107\times 10^{-7} at the 90\% confidence level

    Observation of the WW-Annihilation Decay Ds+ωπ+D^{+}_{s} \rightarrow \omega \pi^{+} and Evidence for Ds+ωK+D^{+}_{s} \rightarrow \omega K^{+}

    Get PDF
    We report on the observation of the WW-annihilation decay Ds+ωπ+D^{+}_{s} \rightarrow \omega \pi^{+} and the evidence for Ds+ωK+D_{s}^{+} \rightarrow \omega K^{+} with a data sample corresponding to an integrated luminosity of 3.19 fb1^{-1} collected with the BESIII detector at the center-of-mass energy s=4.178\sqrt{s} = 4.178 GeV. We obtain the branching fractions B(Ds+ωπ+)=(1.77±0.32stat.±0.11sys.)×103\mathcal{B}(D^{+}_{s} \rightarrow \omega \pi^{+}) = (1.77\pm0.32_{{\rm stat.}}\pm0.11_{{\rm sys.}}) \times 10^{-3} and B(Ds+ωK+)=(0.87±0.24stat.±0.07sys.)×103\mathcal{B}(D^{+}_{s} \rightarrow \omega K^{+}) = (0.87\pm0.24_{{\rm stat.}}\pm0.07_{{\rm sys.}}) \times 10^{-3}, respectively

    Measurement of proton electromagnetic form factors in e+eppˉe^+e^- \to p\bar{p} in the energy region 2.00-3.08 GeV

    Full text link
    The process of e+eppˉe^+e^- \rightarrow p\bar{p} is studied at 22 center-of-mass energy points (s\sqrt{s}) from 2.00 to 3.08 GeV, exploiting 688.5~pb1^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section~(σppˉ\sigma_{p\bar{p}}) of e+eppˉe^+e^- \rightarrow p\bar{p} is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (GE/GM|G_{E}/G_{M}|) and the value of the effective (Geff|G_{\rm{eff}}|), electric (GE|G_E|) and magnetic (GM|G_M|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. GE/GM|G_{E}/G_{M}| and GM|G_M| are determined with high accuracy, providing uncertainties comparable to data in the space-like region, and GE|G_E| is measured for the first time. We reach unprecedented accuracy, and precision results in the time-like region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on non-perturbative Quantum Chromodynamics

    First observations of hch_c \to hadrons

    Get PDF
    Based on (4.48±0.03)×108(4.48 \pm 0.03) \times 10^{8} ψ(3686)\psi(3686) events collected with the BESIII detector, five hch_c hadronic decays are searched for via process ψ(3686)π0hc\psi(3686) \to \pi^0 h_c. Three of them, hcppˉπ+πh_c \to p \bar{p} \pi^+ \pi^-, π+ππ0\pi^+ \pi^- \pi^0, and 2(π+π)π02(\pi^+ \pi^-) \pi^0 are observed for the first time, with statistical significances of 7.4σ\sigma, 4.9σ4.9\sigma, and 9.1σ\sigma, and branching fractions of (2.89±0.32±0.55)×103(2.89\pm0.32\pm0.55)\times10^{-3}, (1.60±0.40±0.32)×103(1.60\pm0.40\pm0.32)\times10^{-3}, and (7.44±0.94±1.56)×103(7.44\pm0.94\pm1.56)\times10^{-3}, respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(hc3(π+π)π0)<8.7×103B(h_c \to 3(\pi^+ \pi^-) \pi^0)<8.7\times10^{-3} and B(hcK+Kπ+π)<5.8×104B(h_c \to K^+ K^- \pi^+ \pi^-)<5.8\times10^{-4} at 90% confidence level.Comment: 17 pages, 16 figure

    Precise Measurements of Branching Fractions for Ds+D_s^+ Meson Decays to Two Pseudoscalar Mesons

    Get PDF
    We measure the branching fractions for seven Ds+D_{s}^{+} two-body decays to pseudo-scalar mesons, by analyzing data collected at s=4.1784.226\sqrt{s}=4.178\sim4.226 GeV with the BESIII detector at the BEPCII collider. The branching fractions are determined to be B(Ds+K+η)=(2.68±0.17±0.17±0.08)×103\mathcal{B}(D_s^+\to K^+\eta^{\prime})=(2.68\pm0.17\pm0.17\pm0.08)\times10^{-3}, B(Ds+ηπ+)=(37.8±0.4±2.1±1.2)×103\mathcal{B}(D_s^+\to\eta^{\prime}\pi^+)=(37.8\pm0.4\pm2.1\pm1.2)\times10^{-3}, B(Ds+K+η)=(1.62±0.10±0.03±0.05)×103\mathcal{B}(D_s^+\to K^+\eta)=(1.62\pm0.10\pm0.03\pm0.05)\times10^{-3}, B(Ds+ηπ+)=(17.41±0.18±0.27±0.54)×103\mathcal{B}(D_s^+\to\eta\pi^+)=(17.41\pm0.18\pm0.27\pm0.54)\times10^{-3}, B(Ds+K+KS0)=(15.02±0.10±0.27±0.47)×103\mathcal{B}(D_s^+\to K^+K_S^0)=(15.02\pm0.10\pm0.27\pm0.47)\times10^{-3}, B(Ds+KS0π+)=(1.109±0.034±0.023±0.035)×103\mathcal{B}(D_s^+\to K_S^0\pi^+)=(1.109\pm0.034\pm0.023\pm0.035)\times10^{-3}, B(Ds+K+π0)=(0.748±0.049±0.018±0.023)×103\mathcal{B}(D_s^+\to K^+\pi^0)=(0.748\pm0.049\pm0.018\pm0.023)\times10^{-3}, where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode Ds+K+Kπ+D_s^+\to K^+K^-\pi^+. Precision of our measurements is significantly improved compared with that of the current world average values

    Measurements of Weak Decay Asymmetries of Λc+pKS0\Lambda_c^+\to pK_S^0, Λπ+\Lambda\pi^+, Σ+π0\Sigma^+\pi^0, and Σ0π+\Sigma^0\pi^+

    Get PDF
    Using e+eΛc+Λˉce^+e^-\to\Lambda_c^+\bar\Lambda_c^- production from a 567 pb1^{-1} data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Λc+pKS0\Lambda_c^+\to pK_S^0, Λπ+\Lambda \pi^+, Σ+π0\Sigma^+\pi^0, and Σ0π+\Sigma^0\pi^+. For the first time, the Λc+\Lambda_c^+ transverse polarization is studied in unpolarized e+ee^+e^- collisions, where a non-zero effect is observed with a statistical significance of 2.1σ\sigma. The decay asymmetry parameters of the Λc+\Lambda_c^+ weak hadronic decays into pKS0pK_S^0, Λπ+\Lambda\pi^+, Σ+π0\Sigma^+\pi^0 and Σ0π+\Sigma^0\pi^+ are measured to be 0.18±0.43(stat)±0.14(syst)0.18\pm0.43(\rm{stat})\pm0.14(\rm{syst}), 0.80±0.11(stat)±0.02(syst)-0.80\pm0.11(\rm{stat})\pm0.02(\rm{syst}), 0.57±0.10(stat)±0.07(syst)-0.57\pm0.10(\rm{stat})\pm0.07(\rm{syst}), and 0.73±0.17(stat)±0.07(syst)-0.73\pm0.17(\rm{stat})\pm0.07(\rm{syst}), respectively. In comparison with previous results, the measurements for the Λπ+\Lambda\pi^+ and Σ+π0\Sigma^+\pi^0 modes are consistent but with improved precision, while the parameters for the pKS0pK_S^0 and Σ0π+\Sigma^0\pi^+ modes are measured for the first time

    Observation of D+f0(500)e+νeD^+ \to f_0(500) e^+\nu_e and Improved Measurements of Dρe+νeD \to\rho e^+\nu_e

    Get PDF
    Using a data sample corresponding to an integrated luminosity of 2.93~fb1^{-1} recorded by the BESIII detector at a center-of-mass energy of 3.7733.773 GeV, we present an analysis of the decays Dˉ0π+π0eνˉe\bar{D}^0\to\pi^+\pi^0 e^-\bar{\nu}_e and D+ππ+e+νeD^+\to\pi^-\pi^+ e^+\nu_e. By performing a partial wave analysis, the π+π\pi^+\pi^- SS-wave contribution to D+ππ+e+νeD^+\to\pi^-\pi^+ e^+\nu_e is observed to be (25.7±1.6±1.1)(25.7\pm1.6\pm1.1)% with a statistical significance greater than 10σ\sigma, besides the dominant PP-wave contribution. This is the first observation of the SS-wave contribution. We measure the branching fractions B(D0ρe+νe)=(1.445±0.058±0.039)×103\mathcal{B}(D^{0} \to \rho^- e^+ \nu_e) = (1.445\pm 0.058 \pm 0.039) \times10^{-3}, B(D+ρ0e+νe)=(1.860±0.070±0.061)×103\mathcal{B}(D^{+} \to \rho^0 e^+ \nu_e) = (1.860\pm 0.070 \pm 0.061) \times10^{-3}, and B(D+f0(500)e+νe,f0(500)π+π)=(6.30±0.43±0.32)×104\mathcal{B}(D^{+} \to f_0(500) e^+ \nu_e, f_0(500)\to\pi^+\pi^-) = (6.30\pm 0.43 \pm 0.32) \times10^{-4}. An upper limit of B(D+f0(980)e+νe,f0(980)π+π)<2.8×105\mathcal{B}(D^{+} \to f_0(980) e^+ \nu_e, f_0(980)\to\pi^+\pi^-) < 2.8 \times10^{-5} is set at the 90% confidence level. We also obtain the hadronic form factor ratios of Dρe+νeD\to \rho e^+\nu_e at q2=0q^{2}=0 assuming the single-pole dominance parameterization: rV=V(0)A1(0)=1.695±0.083±0.051r_{V}=\frac{V(0)}{A_{1}(0)}=1.695\pm0.083\pm0.051, r2=A2(0)A1(0)=0.845±0.056±0.039r_{2}=\frac{A_{2}(0)}{A_{1}(0)}=0.845\pm0.056\pm0.039

    Evidence for the decays of Λc+Σ+η\Lambda^+_{c}\to\Sigma^+\eta and Σ+η\Sigma^+\eta^\prime

    Full text link
    We study the hadronic decays of Λc+\Lambda_{c}^{+} to the final states Σ+η\Sigma^{+}\eta and Σ+η\Sigma^+\eta^\prime, using an e+ee^{+}e^{-} annihilation data sample of 567 pb1^{-1} taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII collider. We find evidence for the decays Λc+Σ+η\Lambda_{c}^{+}\rightarrow\Sigma^{+}\eta and Σ+η\Sigma^+\eta^\prime with statistical significance of 2.5σ2.5\sigma and 3.2σ3.2\sigma, respectively. Normalizing to the reference decays Λc+Σ+π0\Lambda_c^+\to\Sigma^+\pi^0 and Σ+ω\Sigma^+\omega, we obtain the ratios of the branching fractions B(Λc+Σ+η)B(Λc+Σ+π0)\frac{{\mathcal B}(\Lambda_c^+\to\Sigma^+\eta)}{{\mathcal B}(\Lambda_c^+\to\Sigma^+\pi^0)} and B(Λc+Σ+η)B(Λc+Σ+ω)\frac{{\mathcal B}(\Lambda_c^+\to\Sigma^+\eta^\prime)}{{\mathcal B}(\Lambda_c^+\to\Sigma^+\omega)} to be 0.35±0.16±0.030.35 \pm 0.16 \pm 0.03 and 0.86±0.34±0.070.86 \pm 0.34 \pm 0.07, respectively. The upper limits at the 90\% confidence level are set to be B(Λc+Σ+η)B(Λc+Σ+π0)<0.58\frac{{\mathcal B}(\Lambda_c^+\to\Sigma^+\eta)}{{\mathcal B}(\Lambda_c^+\to\Sigma^+\pi^0)}<0.58 and B(Λc+Σ+η)B(Λc+Σ+ω)<1.2\frac{{\mathcal B}(\Lambda_c^+\to\Sigma^+\eta^\prime)}{{\mathcal B}(\Lambda_c^+\to\Sigma^+\omega)}<1.2. Using BESIII measurements of the branching fractions of the reference decays, we determine B(Λc+Σ+η)=(0.41±0.19±0.05)%\mathcal B({\Lambda_{c}^{+}\rightarrow\Sigma^{+}\eta})=(0.41\pm0.19\pm0.05)\% (<0.68%<0.68\%) and B(Λc+Σ+η)=(1.34±0.53±0.21)%\mathcal B({\Lambda_{c}^{+}\rightarrow\Sigma^{+}\eta'})=(1.34\pm0.53\pm0.21)\% (<1.9%<1.9\%). Here, the first uncertainties are statistical and the second systematic. The obtained branching fraction of Λc+Σ+η\Lambda_c^+\to\Sigma^+\eta is consistent with the previous measurement, and the branching fraction of Λc+Σ+η\Lambda_{c}^{+}\rightarrow\Sigma^{+}\eta^{\prime} is measured for the first time.Comment: Accepted by Chin. Phys. C : Chin. Phys. C 43, 083002, (2019
    corecore