Droughts pose significant threats to forest ecosystems globally.Effective forest management strategies,adapted to local conditions,are needed to mitigate negative drought impacts.One proposed strategy is competition r...Droughts pose significant threats to forest ecosystems globally.Effective forest management strategies,adapted to local conditions,are needed to mitigate negative drought impacts.One proposed strategy is competition reduction to increase water availability and,as a result,alleviate drought stress.This study investigates the effect of competition intensity on drought stress and tree growth in European beech(Fagus sylvatica)and pedunculate oak(Quercus robur).We deployed 72 point dendrometers,placed along a competition intensity gradient,in National Park Brabantse Wouden(Belgium),to measure daily minimum tree water deficit(TWD_(min))as a drought stress proxy and daily radial growth at tree level.Our results revealed species-dependent effects of competition intensity(CI).For European beech,competition reductions positively influenced growth and alleviated(1<CI<2)or aggravated(CI<0.5)drought stress.For pedunculate oak,competition intensity did not affect drought stress or growth along the investigated gradient.Environmental variables consistently affected TWDmin and growth of both species.Precipitation reduced TWDmin and increased growth,while vapor pressure deficit led to opposite trends.Thus,environmental conditions and competition can play a critical role in forest dynamics,especially in light of climate change.However,reducing competition through increased management efforts does not seem to be a one-size-fits-all solution to alleviating drought stress.Additionally,there seems to be a trade-off between reducing drought stress and improving tree growth in European beech:tree growth continuously benefited from competition reductions,while under low competition(CI<0.5)drought stress increased.Revisiting or reviving long-term thinning intensity trials encompassing various regions,species,and soil types will be needed to gain comprehensive insights into mitigating drought stress through management interventions under different local stand conditions.展开更多
This paper describes the results of a project on the inspection of visually inaccessible areas of nuclear containment liners and shells via the advanced Magnetostrictive sensor (MsS) Guided Wave (GW) nondestructive in...This paper describes the results of a project on the inspection of visually inaccessible areas of nuclear containment liners and shells via the advanced Magnetostrictive sensor (MsS) Guided Wave (GW) nondestructive inspection technique. Full scale mockups that simulated shell and liner regions of interest in the containment of both a Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) were constructed. Inspections were performed on the mock-ups in three stages to discern the signal attenuation caused by flaws and caused by concrete in the structures. The effect of concrete being in close proximity to the liner and shell was determined, and the capability to detect and size flaws via this GW technique was evaluated.展开更多
Metal halide perovskite solar cells(PSCs)have made substantial progress in power conversion efficiency(PCE)and stability in the past decade thanks to the advancements in perovskite deposition methodology,charge transp...Metal halide perovskite solar cells(PSCs)have made substantial progress in power conversion efficiency(PCE)and stability in the past decade thanks to the advancements in perovskite deposition methodology,charge transport layer(CTL)optimization,and encapsulation technology.Solution-based methods have been intensively investigated and a 25.7% certified efficiency has been achieved.Vacuum vapor deposition protocols were less studied,but have nevertheless received increasing attention from industry and academia due to the great potential for large-area module fabrication,facile integration with tandem solar cell architectures,and compatibility with industrial manufacturing approaches.In this article,we systematically discuss the applications of several promising vacuum vapor deposition techniques,namely thermal evaporation,chemical vapor deposition(CVD),atomic layer deposition(ALD),magnetron sputtering,pulsed laser deposition(PLD),and electron beam evaporation(e-beam evaporation)in the fabrication of CTLs,perovskite absorbers,encapsulants,and connection layers for monolithic tandem solar cells.展开更多
The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by mult...The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by multiple intrinsic developmental signals and environmental factors.KiN1o,the catalytic subunit of the su-crose non-fermenting 1-related protein kinase 1(SnRK1)complex,has been shown to preferentially localize in the nucleus ofmeristemoids,where it phosphorylates and stabilizes the SPEECHLESS transcrip-tion factor,thereby promoting stomatal development.However,the regulatory mechanism governing the nuclear localization of KiN1o in meristemoids remains unclear.Here,we demonstrate that brassinosteroid(BR)inhibits KIN10's nuclear localization by modulating KINβ2 through BR-INSENSITIVE2(BIN2)-mediated phosphorylation.In meristemoids,KIN1o is predominantly nuclear,while KINp2 is mainly cytosolic.Inter-fering with the nuclear localization of KIN10 or enhancing the membrane association of KiNp2 impairs sto-matal development and leads to excessive epidermal cell proliferation.Cell biology and biochemical ana-lyses reveal that BR signaling could inhibit KIN10 nuclear localization by enhancing KIN2 membrane association,while BIN2 interacts with and phosphorylates KINp2 to reduce its membrane association and its interaction with KiN1o.Taken together,these findings suggest that the precise regulation of the subcellular localization of the SnRK1 complex,at least in part by BR signaling,is critical for meristemoid differentiation and stomatal development.展开更多
Insect communities consist of species from several trophic levels that have to forage for suitable resources among and within larger patches of nonresources.To locate their resources,insects use diverse stimuli,includ...Insect communities consist of species from several trophic levels that have to forage for suitable resources among and within larger patches of nonresources.To locate their resources,insects use diverse stimuli,including olfactory,visual,acoustic,tactile and gustatory cues.While most research has focused on cues derived from plants and other insects,there is mounting evidence that insects also respond to volatile organic compounds(VOCs)emitted by microorganisms.However,to date little is known about how the olfactory response of insects within and across different trophic levels is affected by bacterial VOCs.In this study,we used Y-tube bioassays and chemical analysis of VOCs to assess how VOCs emitted by bacteria affect the olfactory response of insects of the same and different trophic levels.Experiments were performed using two aphid species(Amphorophora idaei Börner and Myzus persicae var.nicotianae Blackman),three primary parasitoid species(Aphidius colemani Viereck,A.ervi Haliday,and A.matricariae Viereck),and two hyperparasitoid species(Asaphes suspensus Nees and Dendrocerus aphidum Rondani).Olfactory responses were evaluated for three bacterial strains(Bacillus pumilus ST18.16/133,Curtobacterium sp.ST18.16/085,and Staphylococcus saprophyticus ST18.16/160)that were isolated from the habitat of the insects.Results revealed that insects from all trophic levels responded to bacterial volatiles,but olfactory responses varied between and within trophic levels.All bacteria produced the same set of volatile compounds,but often in different relative concentrations.For 11 of these volatiles we found contrasting correlations between their concentration and the behavior of the primary parasitoids and hyperparasitoids.Furthermore,olfactometer experiments on three of these compounds confirmed the contrasting olfactory responses of primary parasitoids and hyperparasitoids.The potential of these findings for the development of novel semiochemical-based strategies to improve biological aphid control has been discussed.展开更多
The product of the ∧0/b （-B/0） differential production cross-section and the branching fraction of the decay ∧0/b→ J/ψ pK-（-B/0→ J/ψ-K＊（892）0）is measured as a function of the beauty hadron transverse mome...The product of the ∧0/b （-B/0） differential production cross-section and the branching fraction of the decay ∧0/b→ J/ψ pK-（-B/0→ J/ψ-K＊（892）0）is measured as a function of the beauty hadron transverse momentum, PT, and rapidity, y. The kinematic region of the measurements is pT〈20 GeV/c and 2.0 〈g〈4.5.The measurements use a data sample corresponding to an integrated luminosity of 3fb-1 collected by the LHCb detector in pp collisions at centre-of-mass energies √s=7 TeV in 2011 and √s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio,f∧0/b/fd,the branching fraction of the decay ∧0/b→ J/ψ pK-is measured to be B（∧0/b→ J/ψ pK-）=（3.17±0.04±0.07±0.34＋0.45/-0.28）×10-4,where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay -B/0 →J/ψ-K＊（892）0,and the fourth is due to the knowledge of f∧0/b/fd.The sum of the asymmetries in the production and decay between ∧0/b and ∧0/bis also measured as a function of PT and y.The previously published branching fraction of ∧0/b→ J/ψ pπ-,relative to that of ∧0/b→ J/ψ pK-,is updated. The branching fractions of ∧0/b→P＋c（→ J/ψp）K-are determined.展开更多
A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13...A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13 TeV.The data correspond to a total integrated luminosity of 9 fb^-1.No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c^2.Upper limits are set at 95%credibility level on the ratio of the ■^+cc production cross-section times the branching fraction to that ofΛ^+c and ■^++cc baryons.The limits are determined as functions of the ■^+cc mass for different lifetime hypotheses,in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.展开更多
The production of ■baryons in proton-proton collisions at a centre-of-mass energy of √s = 13 TeV is measured in the transverse-momentum range 4<pT<15GeV/c and the rapidity range2.0<y<4.5.The data used in...The production of ■baryons in proton-proton collisions at a centre-of-mass energy of √s = 13 TeV is measured in the transverse-momentum range 4<pT<15GeV/c and the rapidity range2.0<y<4.5.The data used in this measurement correspond to an integrated luminosity of 1.7fb^-1,recorded by the LHCb experiment during 2016.The ratio of the ■ production cross-section times the branching fraction of the■→∧^+cK^-π^+ π^+decay relative to the prompt ∧^+c production cross-section is found to be(2.22±0.27±0.29)×10^-4,assuming the central value of the measured lifetime,where the first uncertainty is statistical and the second systematic.展开更多
The first search for the doubly heavyΩ^(0)_(bc)baryon and a search for the E^(0)_(bc)baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 T...The first search for the doubly heavyΩ^(0)_(bc)baryon and a search for the E^(0)_(bc)baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb^(-1).The baryons are reconstructed via their decays to Λ^(+)_(c)π^(-)and E^(+)_(c)π^(-).No significant excess is fbund for invariant masses between 6700 and 7300 MeV/c^(2),in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ω^(0)_(bc)and E^(0)_(bc)production cross-section times the branching fraction to Λ^(+)_(c)π^(-)(E^(+)_(c)π^(-))relative to that of the Λ^(0)_(b)(E^(0)_(b))baryon,for different lifetime hypotheses,at 95%confidence level.The upper limits range from 0.5 x 10^(-4)to 2.5 x 10^(-4)for theΩ^(0)_(bc)→Λ^(+)_(c)π^(-)(E^(0)_(bc)→Λ^(+)_(c)π^(-))decay,and from 1.4x 10^(-3)to 6.9 x 10^(-3)for theΩ^(0)_(bc)→E^(+)_(c)π^(-)(E^(0)_(bc)→E^(+)_(c)π^(-))decay,depending on the considered mass and lifetime of theΩ^(0)_(bc)(E^(0)_(bc))baryon.展开更多
A search for the rare decay B^(0)→J/ψФis performed using Pp collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7,8 and 13 TeV,corresponding to an integrated luminosity of9 fb.No signific...A search for the rare decay B^(0)→J/ψФis performed using Pp collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7,8 and 13 TeV,corresponding to an integrated luminosity of9 fb.No significant signal of the decay is observed and an upper limitof 1.1x 10^(-7)at 90%confidence level is set on the branching fraction.展开更多
基金supported by the Fonds Wetenschappelijk Onderzoek(FWO)[grant number 1S16824N]the Cost Action CLEANFOREST[E-COST-GRANT-CA21138-c4968ca1].
文摘Droughts pose significant threats to forest ecosystems globally.Effective forest management strategies,adapted to local conditions,are needed to mitigate negative drought impacts.One proposed strategy is competition reduction to increase water availability and,as a result,alleviate drought stress.This study investigates the effect of competition intensity on drought stress and tree growth in European beech(Fagus sylvatica)and pedunculate oak(Quercus robur).We deployed 72 point dendrometers,placed along a competition intensity gradient,in National Park Brabantse Wouden(Belgium),to measure daily minimum tree water deficit(TWD_(min))as a drought stress proxy and daily radial growth at tree level.Our results revealed species-dependent effects of competition intensity(CI).For European beech,competition reductions positively influenced growth and alleviated(1<CI<2)or aggravated(CI<0.5)drought stress.For pedunculate oak,competition intensity did not affect drought stress or growth along the investigated gradient.Environmental variables consistently affected TWDmin and growth of both species.Precipitation reduced TWDmin and increased growth,while vapor pressure deficit led to opposite trends.Thus,environmental conditions and competition can play a critical role in forest dynamics,especially in light of climate change.However,reducing competition through increased management efforts does not seem to be a one-size-fits-all solution to alleviating drought stress.Additionally,there seems to be a trade-off between reducing drought stress and improving tree growth in European beech:tree growth continuously benefited from competition reductions,while under low competition(CI<0.5)drought stress increased.Revisiting or reviving long-term thinning intensity trials encompassing various regions,species,and soil types will be needed to gain comprehensive insights into mitigating drought stress through management interventions under different local stand conditions.
文摘This paper describes the results of a project on the inspection of visually inaccessible areas of nuclear containment liners and shells via the advanced Magnetostrictive sensor (MsS) Guided Wave (GW) nondestructive inspection technique. Full scale mockups that simulated shell and liner regions of interest in the containment of both a Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) were constructed. Inspections were performed on the mock-ups in three stages to discern the signal attenuation caused by flaws and caused by concrete in the structures. The effect of concrete being in close proximity to the liner and shell was determined, and the capability to detect and size flaws via this GW technique was evaluated.
基金financial support of the National Key Research and Development Program of China(2022YFB3803304)The project supported by Tsinghua University Initiative Scientific Research Program(20221080065,20223080044)+9 种基金National Natural Science Foundation of China(No.21872080)State Key Laboratory of Power System and Generation Equipment(Nos.SKLD21Z03 and SKLD20M03)The Chinese Thousand Talents Program for Young Professionals,State Grid Corporation of China,National Bio Energy Co.,Ltd.Grant Number 52789922000DChina Huaneng Group Co.,Ltd.,and grant no.HNKJ20-H88financial support of the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant agreement No.834431)the Spanish Agencia estatal de investigacion(AEI)Grant PDC2021-121317-I00funded by MCIN/AEI/10.13039/501100011033by the“European Union NextGenerationEU/PRTR”the support from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate Universitythe support from the National Natural Science Foundation of China(No.52232008).
文摘Metal halide perovskite solar cells(PSCs)have made substantial progress in power conversion efficiency(PCE)and stability in the past decade thanks to the advancements in perovskite deposition methodology,charge transport layer(CTL)optimization,and encapsulation technology.Solution-based methods have been intensively investigated and a 25.7% certified efficiency has been achieved.Vacuum vapor deposition protocols were less studied,but have nevertheless received increasing attention from industry and academia due to the great potential for large-area module fabrication,facile integration with tandem solar cell architectures,and compatibility with industrial manufacturing approaches.In this article,we systematically discuss the applications of several promising vacuum vapor deposition techniques,namely thermal evaporation,chemical vapor deposition(CVD),atomic layer deposition(ALD),magnetron sputtering,pulsed laser deposition(PLD),and electron beam evaporation(e-beam evaporation)in the fabrication of CTLs,perovskite absorbers,encapsulants,and connection layers for monolithic tandem solar cells.
基金supported by grants from the National Natural Science Foundation of China(32270351 to C.H.,32325006 to M.-Y.B.,U24A20389 to M.-Y.B.,and 32461160287 to M.-Y.B.)Agricultural Variety Improvement Project of Shandong Province(2022LZGC001 to M.-Y.B.and 2024LZGC007 to M.F.)Science and Technology Department of Shandong Province(ZR2022YQ20 to C.H.).
文摘The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by multiple intrinsic developmental signals and environmental factors.KiN1o,the catalytic subunit of the su-crose non-fermenting 1-related protein kinase 1(SnRK1)complex,has been shown to preferentially localize in the nucleus ofmeristemoids,where it phosphorylates and stabilizes the SPEECHLESS transcrip-tion factor,thereby promoting stomatal development.However,the regulatory mechanism governing the nuclear localization of KiN1o in meristemoids remains unclear.Here,we demonstrate that brassinosteroid(BR)inhibits KIN10's nuclear localization by modulating KINβ2 through BR-INSENSITIVE2(BIN2)-mediated phosphorylation.In meristemoids,KIN1o is predominantly nuclear,while KINp2 is mainly cytosolic.Inter-fering with the nuclear localization of KIN10 or enhancing the membrane association of KiNp2 impairs sto-matal development and leads to excessive epidermal cell proliferation.Cell biology and biochemical ana-lyses reveal that BR signaling could inhibit KIN10 nuclear localization by enhancing KIN2 membrane association,while BIN2 interacts with and phosphorylates KINp2 to reduce its membrane association and its interaction with KiN1o.Taken together,these findings suggest that the precise regulation of the subcellular localization of the SnRK1 complex,at least in part by BR signaling,is critical for meristemoid differentiation and stomatal development.
文摘Insect communities consist of species from several trophic levels that have to forage for suitable resources among and within larger patches of nonresources.To locate their resources,insects use diverse stimuli,including olfactory,visual,acoustic,tactile and gustatory cues.While most research has focused on cues derived from plants and other insects,there is mounting evidence that insects also respond to volatile organic compounds(VOCs)emitted by microorganisms.However,to date little is known about how the olfactory response of insects within and across different trophic levels is affected by bacterial VOCs.In this study,we used Y-tube bioassays and chemical analysis of VOCs to assess how VOCs emitted by bacteria affect the olfactory response of insects of the same and different trophic levels.Experiments were performed using two aphid species(Amphorophora idaei Börner and Myzus persicae var.nicotianae Blackman),three primary parasitoid species(Aphidius colemani Viereck,A.ervi Haliday,and A.matricariae Viereck),and two hyperparasitoid species(Asaphes suspensus Nees and Dendrocerus aphidum Rondani).Olfactory responses were evaluated for three bacterial strains(Bacillus pumilus ST18.16/133,Curtobacterium sp.ST18.16/085,and Staphylococcus saprophyticus ST18.16/160)that were isolated from the habitat of the insects.Results revealed that insects from all trophic levels responded to bacterial volatiles,but olfactory responses varied between and within trophic levels.All bacteria produced the same set of volatile compounds,but often in different relative concentrations.For 11 of these volatiles we found contrasting correlations between their concentration and the behavior of the primary parasitoids and hyperparasitoids.Furthermore,olfactometer experiments on three of these compounds confirmed the contrasting olfactory responses of primary parasitoids and hyperparasitoids.The potential of these findings for the development of novel semiochemical-based strategies to improve biological aphid control has been discussed.
基金Supported by CERN and national agencies:CAPES,CNPq,FAPERJ and FINEP(Brazil)NSFC(China)+17 种基金CNRS/IN2P3(France)BMBF,DFG,HGF and MPG(Germany)INFN(Italy)FOM and NWO(The Netherlands)MNi SW and NCN(Poland)MEN/IFA(Romania)Min ES and FANO(Russia)Min ECo(Spain)SNSF and SER(Switzerland)NASU(Ukraine)STFC(United Kingdom)NSF(USA)supported by IN2P3(France),KIT and BMBF(Germany),INFN(Italy),NWOSURF(The Netherlands),PIC(Spain),Grid PP(United Kingdom)support from EPLANET,Marie Sk lodowska-Curie ActionsERC(European Union),Conseil général de Haute-Savoie,Labex ENIGMASS and OCEVU,RégionAuvergne(France),RFBR(Russia),Xunta GalGENCAT(Spain),Royal Society and Royal Commission for the Exhibition of 1851(United Kingdom)
文摘The product of the ∧0/b （-B/0） differential production cross-section and the branching fraction of the decay ∧0/b→ J/ψ pK-（-B/0→ J/ψ-K＊（892）0）is measured as a function of the beauty hadron transverse momentum, PT, and rapidity, y. The kinematic region of the measurements is pT〈20 GeV/c and 2.0 〈g〈4.5.The measurements use a data sample corresponding to an integrated luminosity of 3fb-1 collected by the LHCb detector in pp collisions at centre-of-mass energies √s=7 TeV in 2011 and √s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio,f∧0/b/fd,the branching fraction of the decay ∧0/b→ J/ψ pK-is measured to be B（∧0/b→ J/ψ pK-）=（3.17±0.04±0.07±0.34＋0.45/-0.28）×10-4,where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay -B/0 →J/ψ-K＊（892）0,and the fourth is due to the knowledge of f∧0/b/fd.The sum of the asymmetries in the production and decay between ∧0/b and ∧0/bis also measured as a function of PT and y.The previously published branching fraction of ∧0/b→ J/ψ pπ-,relative to that of ∧0/b→ J/ψ pK-,is updated. The branching fractions of ∧0/b→P＋c（→ J/ψp）K-are determined.
基金support from CERN and from the national agencies:CAPES,CNPq，FAPERJ and FINEP(Brazil)MOST and NSFC(China)+11 种基金CNRS/IN2P3(France)BMBF,DFG and MPG(Germany)INFN(Italy)KWO(Netherlands)MNiSW and NCN(Poland)MEN/IFA(Romania)MinES and FASO(Russia)MinECo(Spain)SNSF and SER(Switzerland)NASU(Ukraine)STFC(United Kingdom)NSF(USA).
文摘A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13 TeV.The data correspond to a total integrated luminosity of 9 fb^-1.No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c^2.Upper limits are set at 95%credibility level on the ratio of the ■^+cc production cross-section times the branching fraction to that ofΛ^+c and ■^++cc baryons.The limits are determined as functions of the ■^+cc mass for different lifetime hypotheses,in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.
基金Supported by CERNnational agencies:CAPES+30 种基金CNPqFAPERJFINEP(Brazil)MOSTNSFC(China)CNRS/IN2P3(France)BMBFDFGMPG(Germany)INFN(Italy)NWO(Netherlands)MNiSWNCN(Poland)MEN/IFA(Romania)MSHE(Russia)MinECo(Spain)SNSFSER(Switzerland)NASU(Ukraine)STFC(United Kingdom)DOE NPNSF(USA)Key Research Program of Frontier Sciences of CAS,CAS PIFIthe Thousand Talents Program(China)RFBRRSFYandex LLC(Russia)GVAXuntaGalGENCAT(Spain)the Royal Society and the Leverhulme Trust(United Kingdom)
文摘The production of ■baryons in proton-proton collisions at a centre-of-mass energy of √s = 13 TeV is measured in the transverse-momentum range 4<pT<15GeV/c and the rapidity range2.0<y<4.5.The data used in this measurement correspond to an integrated luminosity of 1.7fb^-1,recorded by the LHCb experiment during 2016.The ratio of the ■ production cross-section times the branching fraction of the■→∧^+cK^-π^+ π^+decay relative to the prompt ∧^+c production cross-section is found to be(2.22±0.27±0.29)×10^-4,assuming the central value of the measured lifetime,where the first uncertainty is statistical and the second systematic.
基金CAPES,CNPq,FAPERJ and FINEP(Brazil)MOST and NSFC(China)+18 种基金CNRS/IN2P3(France)BMBF,DFG,MPG(Germany)INFN(Italy)NWO(Netherlands)MNiSW,NCN(Poland)MEN/IFA(Romania)MSHE(Russia)MICINN(Spain)SNSF,SER(Switzerland)NASU(Ukraine)STFC(United Kingdom)DOE NP,NSF(USA).We acknowledge the computing resources that are provided by CERN,IN2P3(France),KIT and DESY(Germany),INFN(Italy),SURF(Netherlands),PIC(Spain),GridPP(United Kingdom),RRCKI and Yandex LLC(Russia),CSCS(Switzerland),IFIN-HH(Romania),CBPF(Brazil),PL-GRID(Poland)and NERSC(USA)AvH Foundation(Germany)EPLANET,Marie Sklodowska-Curie Actions and ERC(European Union)A*MIDEX,ANR,Labex P2IO and OCEVU,Region Auvergne-Rhdne-Alpes(France)Key Research Program of Frontier Sciences of CAS,CAS PIFI,CAS CCEPP,Fundamental Research Funds for the Central Universities,and Sci.Tech.Program of Guangzhou(China)RFBR,RSF and Yandex LLC(Russia)GVA,XuntaGal,GENCAT(Spain)the Leverhulme Trust,the Royal Society and UKRI(United Kingdom)。
文摘The first search for the doubly heavyΩ^(0)_(bc)baryon and a search for the E^(0)_(bc)baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb^(-1).The baryons are reconstructed via their decays to Λ^(+)_(c)π^(-)and E^(+)_(c)π^(-).No significant excess is fbund for invariant masses between 6700 and 7300 MeV/c^(2),in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ω^(0)_(bc)and E^(0)_(bc)production cross-section times the branching fraction to Λ^(+)_(c)π^(-)(E^(+)_(c)π^(-))relative to that of the Λ^(0)_(b)(E^(0)_(b))baryon,for different lifetime hypotheses,at 95%confidence level.The upper limits range from 0.5 x 10^(-4)to 2.5 x 10^(-4)for theΩ^(0)_(bc)→Λ^(+)_(c)π^(-)(E^(0)_(bc)→Λ^(+)_(c)π^(-))decay,and from 1.4x 10^(-3)to 6.9 x 10^(-3)for theΩ^(0)_(bc)→E^(+)_(c)π^(-)(E^(0)_(bc)→E^(+)_(c)π^(-))decay,depending on the considered mass and lifetime of theΩ^(0)_(bc)(E^(0)_(bc))baryon.
基金support from AvH Foundation(Germany)EPLANET,Marie Sk lodowska-Curie Actions and ERC(European Union)+11 种基金A*MIDEXANRLabex P2IOOCEVURégion Auvergne-Rh?ne-Alpes(France)Key Research Program of Frontier Sciences of CASCAS PIFIThousand Talents ProgramSci.&Tech.Program of Guangzhou(China)RFBR,RSF and Yandex LLC(Russia)GVA,Xunta Gal and GENCAT(Spain)the Royal Society and the Leverhulme Trust(United Kingdom)。
文摘A search for the rare decay B^(0)→J/ψФis performed using Pp collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7,8 and 13 TeV,corresponding to an integrated luminosity of9 fb.No significant signal of the decay is observed and an upper limitof 1.1x 10^(-7)at 90%confidence level is set on the branching fraction.
