19 research outputs found

    Estimation of the Fertilizer Response of Maize and Bean Intercropping Using Sole Crop Response Equations

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    Maize (Zea mays L.) and bean (Phaseolus vulgaris L.) are commonly grown in association in eastern and southern Africa. Results from 64 fertilizer response trials conducted in Kenya were used to study the relationship between maize monoculture response to fertilizer nitrogen and phosphorus and the intercrop response. The intercrop was more productive that the monoculture with no fertilizer applied, but overall responses of systems to applied nutrients did not differ. Maize, both in monoculture and intercropped, responded more frequently to applied N than did the intercropped bean. Frequency of response to applied P was similar for both crops and both production systems. The basis was established to estimate maize-bean intercrop fertilizer response using response equations for maize monoculture.En Afrique de l'est et australe, le mais (Zea mays L.) et le haricot (Phaseolus vulgaris L.) sont habituellement cultives en association. Les resultats de 64 essais de reponse aux fertilisants conduits au Kenya etaient utilises pour etudier le rapport entre les reponses de l'azote et du phosphore au mais en monoculture et en culture mixte. La culture mixte etait plus productive que la monoculture qui n'a pas renu de fertilisants. Toutes les reponses des systemes qui ont renu les fertilisants n'etaient pas differentes. Le mais, a la lois en monoculture et en association, repondait plus a l'application d'azote que le haricot en association. La frequence de reponses a l'application du phosphore etait similaire pour toutes les 2 cultures et dans tous les 2 systemes de production. La base etait ainsi etablie pour estimer la reponse de fertilisants a la culture associee de mais - haricot en utilisant les equations de reponse pour le mais en monoculture

    Observation of Resonance Structures in e+e- →π+π-ψ2 (3823) and Mass Measurement of ψ2 (3823)

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    © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Using a data sample corresponding to an integrated luminosity of 11.3 fb-1 collected at center-of-mass energies from 4.23 to 4.70 GeV with the BESIII detector, we measure the product of the e+e-→π+π-ψ2(3823) cross section and the branching fraction B[ψ2(3823)→γχc1]. For the first time, resonance structure is observed in the cross section line shape of e+e-→π+π-ψ2(3823) with significances exceeding 5σ. A fit to data with two coherent Breit-Wigner resonances modeling the s-dependent cross section yields M(R1)=4406.9±17.2±4.5 MeV/c2, Γ(R1)=128.1±37.2±2.3 MeV, and M(R2)=4647.9±8.6±0.8 MeV/c2, Γ(R2)=33.1±18.6±4.1 MeV. Though weakly disfavored by the data, a single resonance with M(R)=4417.5±26.2±3.5 MeV/c2, Γ(R)=245±48±13 MeV is also possible to interpret data. This observation deepens our understanding of the nature of the vector charmoniumlike states. The mass of the ψ2(3823) state is measured as (3823.12±0.43±0.13) MeV/c2, which is the most precise measurement to date

    Measurement of proton electromagnetic form factors in the time-like region using initial state radiation at BESIII

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    The electromagnetic process is studied with the initial-state-radiation technique using 7.5 fb−1 of data collected by the BESIII experiment at seven energy points from 3.773 to 4.600 GeV. The Born cross section and the effective form factor of the proton are measured from the production threshold to 3.0 GeV/ using the invariant-mass spectrum. The ratio of electric and magnetic form factors of the proton is determined from the analysis of the proton-helicity angular distribution

    Study of the processes χcJ → Ξ−Ξ¯+ and Ξ0Ξ¯0

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    Using 448.1 × 106 ψ(3686) decays collected with the BESIII detector at the BEPCII e+e− storage rings, the branching fractions and angular distributions of the decays χcJ → Ξ−Ξ¯¯¯¯+ and Ξ0Ξ¯¯¯¯0 (J = 0, 1, 2) are measured based on a partial-reconstruction technique. The decays χc1 → Ξ0Ξ¯¯¯¯0 and χc2 → Ξ0Ξ¯¯¯¯0 are observed for the first time with statistical significances of 7σ and 15σ, respectively. The results of this analysis are in good agreement with previous measurements and have significantly improved precision
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