This work presents the results of computer simulation of neutronic processes in a high-temperature gas-cooled thorium reactor for 30 different options of core loading.To guarantee stable and long-term reactor operatio...This work presents the results of computer simulation of neutronic processes in a high-temperature gas-cooled thorium reactor for 30 different options of core loading.To guarantee stable and long-term reactor operation(7-10 years),the quantity of fuel compact dispersion phase and starting fuel composition was selected.It is demonstrated that it is possible in principle to substitute the near-axial recirculation zone of the reactor core by a long magnetic trap with a high-temperature plasma column for generating thermonuclear neutrons.The distribution of neutron yield along the length of the plasma source is also presented.Such a thorium reactor,with a near-axial source of extra neutrons,can be applied for researching thermophysical and neutronic characteristics of dispersion thorium fuel to improve its properties.The results of the work are of great interest from the perspective of future advancement of the thermonuclear power industry,by means of creation of a hybrid installation based on a thorium reactor with a long plasma column as a source of additional neutrons.展开更多
It is shown that a steepening of the radial plasma pressure profile leads to a decrease in the critical value of beta,above which,small-scale balloon-type perturbations in a mirror trap become unstable.This may mean t...It is shown that a steepening of the radial plasma pressure profile leads to a decrease in the critical value of beta,above which,small-scale balloon-type perturbations in a mirror trap become unstable.This may mean that small-scale ballooning instability leads to a smoothing of the radial plasma profile.The critical beta values for the real magnetic field of the gas-dynamic trap and various plasma pressure radial profiles was also calculated.For a plasma with a parabolic profile critical beta is evaluated at the level of 0.72.A previous theoretical prediction for this trap was almost two times lower than maximal beta 0.6 achieved experimentally.展开更多
There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac...There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.展开更多
Nanoparticles(NPs)can be transported via the nose-to-brain(N_(2)B)route.Nonetheless,quantitative data on their spatiotemporal dynamics and regulation of the N_(2)B transport are largely lacking.We surveyed metal oxide...Nanoparticles(NPs)can be transported via the nose-to-brain(N_(2)B)route.Nonetheless,quantitative data on their spatiotemporal dynamics and regulation of the N_(2)B transport are largely lacking.We surveyed metal oxide/hydroxide NPs as magnetic resonance imaging(MRI)contrasts for quantitative N_(2)B tracking.NPs containing divalent transition metals were the only ones capable of N_(2)B transmission.Using T1-weighted(T1W)MRI,we showed that Mn_(3)O_(4)-NPs were readily engulfed by olfactory receptor neurons(ORNs)without disrupting olfactory sensing,we mapped their N_(2)B trajectory.Within neurons,the Mn_(3)O_(4)-NPs were localized to the cytosol,mitochondria,vesicles,moved at mixed fast and slow axonal transport velocities intraand extra-vesicularly through ORNs.The NPs’axonal transport is dependent on neuronal activity and microtubule integrity.The Mn_(3)O_(4)-NPs were trans-synaptically transmitted through at least four synapses across the olfactory tract.Trans-synaptic transmission of the NPs was dependent on N-type Ca^(2+)channels and NMDA receptors but blocked by GABAB receptor activation.A five-parameter Weibull signal increase/decrease model fitted to the T1W MRI data allowed for estimating kinetic parameters of Mn_(3)O_(4)-NP accumulation/elimination.Absolute and relative accumulation rates,but not elimination,correlated negatively with the number of synapses from ORNs,indicating a coupling of the NPs’N_(2)B transport with spontaneous neuronal activity.Accordingly,olfactory stimuli(2,5-dimethylpyrazine and acetophenone)significantly modulated and rerouted the Mn_(3)O_(4)-NP N_(2)B transport odor specifically.Finally,the NPs’trans-synaptic transmission was impaired by aging and the onset of Parkinson’s disease.These data suggest new approaches to diagnostics,functional neuroimaging,controlling N_(2)B drug delivery.展开更多
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the ...The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on: Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http ://pdg. lbl. gov.展开更多
Revised August 2013 by M.J. Syphers (MSU) and F. Zimmermann (CERN).29.1. Luminosity This article provides background for the High-Energy Collider Parameter Tables that follow. The number of events, Nexp, is the pr...Revised August 2013 by M.J. Syphers (MSU) and F. Zimmermann (CERN).29.1. Luminosity This article provides background for the High-Energy Collider Parameter Tables that follow. The number of events, Nexp, is the product of the cross section of interest,展开更多
Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESⅢdetector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb^(-1),th...Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESⅢdetector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb^(-1),the process e^(+)e^(-)→pppñπ+c.c.is observed for the first time with a statistical significance of 11.5σ.The average Born cross sections in the energy ranges of(4.160,4.380)GeV,(4.400,4.600)GeV and(4.610,4.700)GeV are measured to be(21.5±5.7±1.2)fb,(46.3±10.6±2.5)fb and(59.0±9.4±3.2)fb,respectively,where the first uncertainties are statistical and the second are systematic.The line shapes of the pñ and ppπ^(-)invariant mass spectra are consistent with phase space distributions,indicating that no hexaquark or di-baryon state is observed.展开更多
Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb-1,collected by the BESⅢdetector in the energy region between 4599.53 MeV and 4698.82 MeV,we report the first obser...Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb-1,collected by the BESⅢdetector in the energy region between 4599.53 MeV and 4698.82 MeV,we report the first observations of the Cabibbo-suppressed decaysΛ_(c)^(+)→nπ^(+)π^(0),Λ_(c)^(+)→nπ^(+)π^(-)π^(+),and the Cabibbo-favored decayΛ_(c)^(+)→nK^(-)π^(+)π^(+)with statistical significances of 7.9σ,7.8σ,and>10σ,respectively.The branching fractions of these decays are measured to be B(Λ_(c)^(+)→nπ^(+)π^(0))=(0.64±0.09±0.02)%,B(Λ_(c)^(+)→nπ^(+)π^(-)π^(+))=(0.45±0.07±0.03)%,and B(Λ_(c)^(+)→nK^(-)π^(+)π^(+))=(1.90±0.08±0.09)%,where the first uncertainties are statistical and the second are systematic.We find that the branching fraction of the decayΛ_(c)^(+)→nπ^(+)π^(0)is about one order of magnitude higher than that ofΛ_(c)^(+)→nπ^(+).展开更多
Table 6.1 Abridged from pdg. ibl.gov/AtomicNuclearProperties by D. E. Groom (2007). See web pages for more detail about entries in this table including chemical formulae, and for several hundred other entries. Quant...Table 6.1 Abridged from pdg. ibl.gov/AtomicNuclearProperties by D. E. Groom (2007). See web pages for more detail about entries in this table including chemical formulae, and for several hundred other entries. Quantities in parentheses are for gases at 20℃ and 1 atm, and square brackets indicate evaluation at 0℃ and 1 atm. Boiling points are at 1 atm.展开更多
Written November 2013 by M. Carena (Fermi National Accelerator Laboratory and the University of Chicago), C. Grojean (ICREA at IFAE, Universitat Autbnoma de Barcelona), M, Kado (Laboratoire de l'Accelerateur Lin...Written November 2013 by M. Carena (Fermi National Accelerator Laboratory and the University of Chicago), C. Grojean (ICREA at IFAE, Universitat Autbnoma de Barcelona), M, Kado (Laboratoire de l'Accelerateur Lineaire, LAL and CERN), and V. Sharma (University of California San Diego).展开更多
From 2011 to 2014, the BESIII experiment collected about 5 fb^-1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon proce...From 2011 to 2014, the BESIII experiment collected about 5 fb^-1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process e+e- →yma/Fsμ^+μ^-, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of the time during data taking.展开更多
The decay channel ψ′→ π 〉+π^-J/ψ(J/ψ 〉 γp^-p) is studied using a sample of 1.06 × 10^8 ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p...The decay channel ψ′→ π 〉+π^-J/ψ(J/ψ 〉 γp^-p) is studied using a sample of 1.06 × 10^8 ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p^-p invariant mass spectrum. The enhancement can be fitted with an S-wave Breit-Wigner resonance function with a resulting peak mass of M = 1861-13^+6 (stat)-26^+7 (syst) MeV/c^2 and a narrow width that is Г 〈 38 MeV/c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.展开更多
By analyzing 2.93 fb-1 data collected at the center-of-mass energy v/S = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D+- k0e+ ve via k0-π0π0 - (8.59 ...By analyzing 2.93 fb-1 data collected at the center-of-mass energy v/S = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D+- k0e+ ve via k0-π0π0 - (8.59 ± 0.14 ± 0.21)% using k0- k0-π0π0, where the first uncertainty is statistical and the second systematic. Our result is consistent with previous measurements within uncertainties..展开更多
The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The err...The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The error is systematic dominant; the statistical error is negligible.展开更多
The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting in...The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting inclusive hadronic events,where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of ψ(3686) events for the two data taking periods is(448.1±2.9)×10^6.展开更多
From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ exper...From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.展开更多
From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium s...From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.展开更多
Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bh...Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bhabha scattering events, the integrated luminosities of the two data sets are measured to be (44.49±0.02±0.44) pb-1 and (2916.94±0.18±29.17) pb-1, respectively, where the first error is statistical and the second error is systematic.展开更多
文摘This work presents the results of computer simulation of neutronic processes in a high-temperature gas-cooled thorium reactor for 30 different options of core loading.To guarantee stable and long-term reactor operation(7-10 years),the quantity of fuel compact dispersion phase and starting fuel composition was selected.It is demonstrated that it is possible in principle to substitute the near-axial recirculation zone of the reactor core by a long magnetic trap with a high-temperature plasma column for generating thermonuclear neutrons.The distribution of neutron yield along the length of the plasma source is also presented.Such a thorium reactor,with a near-axial source of extra neutrons,can be applied for researching thermophysical and neutronic characteristics of dispersion thorium fuel to improve its properties.The results of the work are of great interest from the perspective of future advancement of the thermonuclear power industry,by means of creation of a hybrid installation based on a thorium reactor with a long plasma column as a source of additional neutrons.
基金financially supported by the Ministry of Education and Science of the Russian Federationsupported by Chinese Academy of Sciences Presidents International Fellowship Initiative(PIFI)under Grant No.2022VMA0007Chinese Academy of Sciences International Partnership Program under Grant No.116134KYSB20200001。
文摘It is shown that a steepening of the radial plasma pressure profile leads to a decrease in the critical value of beta,above which,small-scale balloon-type perturbations in a mirror trap become unstable.This may mean that small-scale ballooning instability leads to a smoothing of the radial plasma profile.The critical beta values for the real magnetic field of the gas-dynamic trap and various plasma pressure radial profiles was also calculated.For a plasma with a parabolic profile critical beta is evaluated at the level of 0.72.A previous theoretical prediction for this trap was almost two times lower than maximal beta 0.6 achieved experimentally.
基金Supported in part by National Key Basic Research Program of China (2015CB856700)National Natural Science Foundation of China (NSFC) (11335008,11425524, 11625523, 11635010, 11735014, 11822506, 11935018)+18 种基金the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics (CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532257, U1532258, U1732263)CAS Key Research Program of Frontier Science (QYZDJ-SSW-SLH003, QYZDJ-SSW-SLH040)100 Talents Program of CASCAS PIFIthe Thousand Talents Program of ChinaIN-PAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG under Contracts NosCollaborative Research Center CRC 1044, FOR 2359Istituto Nazionale di Fisica Nucleare, ItalyKoninklijke Nederlandse Akademie van Wetenschappen (KNAW) (530-4CDP03)Ministry of Development of Turkey (DPT2006K-120470)National Science and Technology fundThe Knut and Alice Wallenberg Foundation (Sweden) (2016.0157)The Swedish Research CouncilU. S. Department of Energy (DE-FG02-05ER41374, DESC-0010118, DE-SC-0012069)University of Groningen (Ru G) and the Helmholtzzentrum fuer Schwerionenforschung Gmb H (GSI), Darmstadtthe Russian Ministry of Science and Higher Education (14.W03.31.0026).
文摘There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.
基金the Russian Foundation for Basic Research RFBR(No.20-16-00078)the Centers of Collective Use“National Center of Catalyst Research”of Boreskov Institute of Catalysis SB RAS and by the budget project(No.FWNR-2022-0023 and project FWNR-2022-0004)+1 种基金the equipment of the Center for Genetic Resources of Laboratory Animals at ICG SB RAS,supported by the Ministry of Education and Science of Russia(Unique identifier of the project RFMEFI62119X0023)TEM imaging was performed at the Microscopy Center of Biological Subjects ICG SB RAS(project#0259-2021-0011)。
文摘Nanoparticles(NPs)can be transported via the nose-to-brain(N_(2)B)route.Nonetheless,quantitative data on their spatiotemporal dynamics and regulation of the N_(2)B transport are largely lacking.We surveyed metal oxide/hydroxide NPs as magnetic resonance imaging(MRI)contrasts for quantitative N_(2)B tracking.NPs containing divalent transition metals were the only ones capable of N_(2)B transmission.Using T1-weighted(T1W)MRI,we showed that Mn_(3)O_(4)-NPs were readily engulfed by olfactory receptor neurons(ORNs)without disrupting olfactory sensing,we mapped their N_(2)B trajectory.Within neurons,the Mn_(3)O_(4)-NPs were localized to the cytosol,mitochondria,vesicles,moved at mixed fast and slow axonal transport velocities intraand extra-vesicularly through ORNs.The NPs’axonal transport is dependent on neuronal activity and microtubule integrity.The Mn_(3)O_(4)-NPs were trans-synaptically transmitted through at least four synapses across the olfactory tract.Trans-synaptic transmission of the NPs was dependent on N-type Ca^(2+)channels and NMDA receptors but blocked by GABAB receptor activation.A five-parameter Weibull signal increase/decrease model fitted to the T1W MRI data allowed for estimating kinetic parameters of Mn_(3)O_(4)-NP accumulation/elimination.Absolute and relative accumulation rates,but not elimination,correlated negatively with the number of synapses from ORNs,indicating a coupling of the NPs’N_(2)B transport with spontaneous neuronal activity.Accordingly,olfactory stimuli(2,5-dimethylpyrazine and acetophenone)significantly modulated and rerouted the Mn_(3)O_(4)-NP N_(2)B transport odor specifically.Finally,the NPs’trans-synaptic transmission was impaired by aging and the onset of Parkinson’s disease.These data suggest new approaches to diagnostics,functional neuroimaging,controlling N_(2)B drug delivery.
基金supported by the Director,Office of Science,Office of High Energy Physics of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231the U.S.National Science Foundation under Agreement No.PHY-0652989+3 种基金the European Laboratory for Particle Physics(CERN)an implementing arrangement between the governments of Japan(MEXT:Ministry of Education,Culture,Sports,Science and Technology)and the United States(DOE)on cooperative research and developmentthe Italian National Institute of Nuclear Physics(INFN)B.C.F.was supported by the U.S.National Science Foundation Grant PHY-1214082
文摘The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on: Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http ://pdg. lbl. gov.
文摘Revised August 2013 by M.J. Syphers (MSU) and F. Zimmermann (CERN).29.1. Luminosity This article provides background for the High-Energy Collider Parameter Tables that follow. The number of events, Nexp, is the product of the cross section of interest,
基金Supported in part by National Key R&D Program of China under Contracts Nos.Supported in part by National Key R&D Program of China(2020YFA0406300,2020YFA0406400)National Natural Science Foundation of China(NSFC)(11975118,11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012,12022510,12025502,12035009,12035013,12061131003,12075252,12192260,12192261,12192262,12192263,12192264,12192265)+19 种基金the Natural Science Foundation of Hunan Province of China(2019JJ30019)the Science and Technology Innovation Program of Hunan Province(2020RC3054)the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1732263,U1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)European Union Horizon 2020 research and innovation programme under Contract No.Marie Sklodowska-Curie grant agreement(894790)German Research Foundation DFG(43159800)Collaborative Research Center CRC 1044,FOR 2359,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)National Science and Technology fundOlle Engkvist Foundation(200-0605)STFC(United Kingdom)The Knut and Alice Wallenberg Foundation(Sweden)(2016.0157)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374,DE-SC-0012069)。
文摘Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESⅢdetector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb^(-1),the process e^(+)e^(-)→pppñπ+c.c.is observed for the first time with a statistical significance of 11.5σ.The average Born cross sections in the energy ranges of(4.160,4.380)GeV,(4.400,4.600)GeV and(4.610,4.700)GeV are measured to be(21.5±5.7±1.2)fb,(46.3±10.6±2.5)fb and(59.0±9.4±3.2)fb,respectively,where the first uncertainties are statistical and the second are systematic.The line shapes of the pñ and ppπ^(-)invariant mass spectra are consistent with phase space distributions,indicating that no hexaquark or di-baryon state is observed.
基金Supported in part by National Key R&D Program of China(2020YFA0406400,2020YFA0406300)National Natural Science Foundation of China(NSFC)(11635010,11735014,11805086,11835012,11935015,11935016,11935018,11975011,11961141012,12022510,12025502,12035009,12035013,12192260,12192261,12192262,12192263,12192264,12192265)+20 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1832207)the CAS Center for Excellence in Particle Physics(CCEPP)100 Talents Program of CASFundamental Research Funds for the Central Universities,Lanzhou University,University of Chinese Academy of SciencesThe Institute of Nuclear and Particle Physics(INPAC)Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)German Research Foundation DFG(443159800)Collaborative Research Center CRC 1044,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)National Science and Technology fundNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(B16F640076STFC)(United Kingdom)Suranaree University of Technology(SUT)Thailand Science Research and Innovation(TSRI)National Science Research and Innovation Fund(NSRF)(160355)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DEFG02-05ER41374)。
文摘Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb-1,collected by the BESⅢdetector in the energy region between 4599.53 MeV and 4698.82 MeV,we report the first observations of the Cabibbo-suppressed decaysΛ_(c)^(+)→nπ^(+)π^(0),Λ_(c)^(+)→nπ^(+)π^(-)π^(+),and the Cabibbo-favored decayΛ_(c)^(+)→nK^(-)π^(+)π^(+)with statistical significances of 7.9σ,7.8σ,and>10σ,respectively.The branching fractions of these decays are measured to be B(Λ_(c)^(+)→nπ^(+)π^(0))=(0.64±0.09±0.02)%,B(Λ_(c)^(+)→nπ^(+)π^(-)π^(+))=(0.45±0.07±0.03)%,and B(Λ_(c)^(+)→nK^(-)π^(+)π^(+))=(1.90±0.08±0.09)%,where the first uncertainties are statistical and the second are systematic.We find that the branching fraction of the decayΛ_(c)^(+)→nπ^(+)π^(0)is about one order of magnitude higher than that ofΛ_(c)^(+)→nπ^(+).
文摘Table 6.1 Abridged from pdg. ibl.gov/AtomicNuclearProperties by D. E. Groom (2007). See web pages for more detail about entries in this table including chemical formulae, and for several hundred other entries. Quantities in parentheses are for gases at 20℃ and 1 atm, and square brackets indicate evaluation at 0℃ and 1 atm. Boiling points are at 1 atm.
基金supported by Fermilab,that is operated by Fermi Research Alliance,LLC under Contract No.DE-AC02-07CH11359 with the United States Department of EnergyC.G.is supported by the Spanish Ministry MICINN under contract FPA2010-17747+2 种基金the European Commission under the ERC Advanced Grant 22637 MassTeVthe contract PITN-GA-2009-237920 UNILHC.M.K. is supported by the ANR HiggsNet grant.V.S.is supported by the grant DE-SC0009919 of the United States Department of Energy
文摘Written November 2013 by M. Carena (Fermi National Accelerator Laboratory and the University of Chicago), C. Grojean (ICREA at IFAE, Universitat Autbnoma de Barcelona), M, Kado (Laboratoire de l'Accelerateur Lineaire, LAL and CERN), and V. Sharma (University of California San Diego).
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(11125525,11235011.11322544,11335008,11425524,Y61137005C)+7 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,CAS Center for Excellence in Particle Physics(CCEPP),Collaborative Innovation Center for Particles and Interactions(CICPI),Joint Large-Scale Scientific Facility Funds of NSFC and CAS(11179007,U1232201,U1332201),CAS(KJCX2-YW-N29,KJCX2-YWN45),100 Talents Program of CASNational 1000 Talents Program of China,INPACShanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)Swedish Research Council,U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,University of Groningen(RuG)and Helniholtzzentrum fuer Schwerionenforschung GmbH(GSI),DarmstadtWCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘From 2011 to 2014, the BESIII experiment collected about 5 fb^-1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process e+e- →yma/Fsμ^+μ^-, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of the time during data taking.
基金Supported by Ministry of Science and Technology of China (2009CB825200)National Natural Science Foundation of China(NSFC) (10625524,10821063,10825524,10835001,10935007)+6 种基金Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program,CAS (KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CASIstituto Nazionale di Fisica Nucleare,Italy,Russian Foundation for Basic Research (08-02-2221, 08-02-92200-NSFC-a)Siberian Branch of Russian Academy of Science,joint project No 32 with CAS,Chinese University of Hong Kong Focused Investment Grant (3110031)U. S. Department of Energy(DE-FG02-04ER41291,DE-FG02-91ER40682,DE-FG02-94ER40823)WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)the A.P. Sloan Foundation
文摘The decay channel ψ′→ π 〉+π^-J/ψ(J/ψ 〉 γp^-p) is studied using a sample of 1.06 × 10^8 ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p^-p invariant mass spectrum. The enhancement can be fitted with an S-wave Breit-Wigner resonance function with a resulting peak mass of M = 1861-13^+6 (stat)-26^+7 (syst) MeV/c^2 and a narrow width that is Г 〈 38 MeV/c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.
基金Supported by National Key Basic Research Program of China(2009CB825204,2015CB856700)National Natural Science Foundation of China(NSFC)(10935007,11125525,11235011,11305180,11322544,11335008,11425524,11475123)+14 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,CAS Center for Excellence in Particle Physics(CCEPP)Collaborative Innovation Center for Particles and Interactions(CICPI)Joint Large-Scale Scientific Facility Funds of NSFC and CAS(11179007,U1232201,U1332201,U1532101)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CASNational 1000 Talents Program of ChinaINPAC and Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Koninklijke Nederlandse Akademie van Wetenschappen(KNAW)(530-4CDP03)Ministry of Development of Turkey(DPT2006K-120470)National Natural Science Foundation of China(NSFC)(11405046,U1332103)Russian Foundation for Basic Research(14-07-91152)Swedish Resarch Council,U.S.Department of Energy(DE-FG02-04ER41291,DE>FG02-05ER41374,DE1-SC0012069,DESC0010118)U.S.National Science Foundation,University of Groningen(RuG)Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘By analyzing 2.93 fb-1 data collected at the center-of-mass energy v/S = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D+- k0e+ ve via k0-π0π0 - (8.59 ± 0.14 ± 0.21)% using k0- k0-π0π0, where the first uncertainty is statistical and the second systematic. Our result is consistent with previous measurements within uncertainties..
基金Supported by Ministry of Science and Technology of China(2009CB825200)National Natural Science Foundation of China(NSFC)(10625524,10821063,10825524,10835001,10935007,11125525,10975143,10979058),Joint Funds of the National Natural Science Foundation of China(11079008,11179007)+5 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramCAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-91ER40682,DE-FG02-94ER40823)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘The number of φ' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×(1.00±0.81%)×10^6. The error is systematic dominant; the statistical error is negligible.
基金Supported by the Ministry of Science and Technology of China(2009CB825200)National Natural Science Foundation of China(NSFC)(11235011,11322544,11335008,11425524,11475207)+16 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe Collaborative Innovation Center for Particlcs and Interactions(CICPI)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179014)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179007,U1232201,U1532257,U1532258)Joint Funds of the National Natural Science Foundation of China(11079008)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CASNational 1000 Talents Program of ChinaGerman Research Foundation DFG(Collaborative Research Center CRC 1044)Istituto Nazionale di Fisica Nucleare,ItalyKoninklijke Nederlandse Akademie van Wetenschappen(KNAW)(530-4CDP03)Ministry of Development of Turkey(DPT2006K-120470)National Natural Science Foundation of China(11205082)The Swedish Research Council,U.S.Department of Energy(DE-FG02-05ER41374,DE-SC-0010118,DE-SC-0010504)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘The numbers of ψ(3686) events accumulated by the BESⅢ detector for the data taken during 2009 and 2012 are determined to be(107.0±0.8)×10^6 and(341.1±2.1)×10^6, respectively, by counting inclusive hadronic events,where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of ψ(3686) events for the two data taking periods is(448.1±2.9)×10^6.
基金supported by the following funding sources:Science Committee of the Republic of Armenia Grant No.18T-1C180Australian Research Council and research grant Nos.DP180102629,DP170102389,DP170102204,DP150103061,FT130100303,and FT130100018+37 种基金Austrian Federal Ministry of Education,Science and Research,and Austrian Science Fund No.P 31361-N36Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIEChinese Academy of Sciences and research grant No.QYZDJ-SSW-SLH011National Natural Science Foundation of China and research grant Nos.11521505,11575017,11675166,11761141009,11705209,and 11975076LiaoNing Revitalization Talents Program under contract No.XLYC1807135Shanghai Municipal Science and Technology Committee under contract No.19ZR1403000Shanghai Pujiang Program under Grant No.18PJ1401000the CAS Center for Excellence in Particle Physics(CCEPP)the Ministry of Education,Youth and Sports of the Czech Republic under Contract No.LTT17020Charles University grants SVV260448 and GAUK 404316European Research Council,7th Framework PIEF-GA-2013-622527Horizon 2020 Marie Sklodowska-Curie grant agreement No.700525’NIOBE,’Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER grant agreement No.644294Horizon 2020 ERC-Advanced Grant No.267104NewAve No.638528(European grants)L’Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS(France),BMBF,DFG,HGF,MPG and AvH Foundation(Germany)Department of Atomic Energy and Department of Science and Technology(India)Israel Science Foundation grant No.2476/17United States-Israel Binational Science Foundation grant No.2016113Istituto Nazionale di Fisica Nucleare and the research grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research grant Nos.16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,26220706,and 26400255the National Institute of Informatics,and Science Information NETwork 5(SINET5)the Ministry of Education,Culture,Sports,Science,and Technology(MEXT)of JapanNational Research Foundation(NRF)of Korea Grant Nos.2016R1D1A1B01010135,2016R1D1A1B02012900,2018R1A2B3003643,2018R1A6A1A06024970,2018R1D1A1B07047294,2019K1A3A7A09033840,and 2019R1I1A3A01058933Radiation Science Research Institute,Foreign Large-size Research Facility Application Supporting project,the Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIADUniversiti Malaya RU grant,Akademi Sains Malaysia and Ministry of Education MalaysiaFrontiers of Science Program contracts FOINS-296,CB-221329,CB-236394,CB-254409,and CB-180023,and the Thematic Networks program(Mexico)the Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation,Agreement14.W03.31.0026Slovenian Research Agency and research grant Nos.J1-9124 and P1-0135Agencia Estatal de Investigacion,Spain grant Nos.FPA2014-55613-P and FPA2017-84445-P,and CIDEGENT/2018/020 of Generalitat ValencianaMinistry of Science and Technology and research grant Nos.MOST106-2112-M-002-005-MY3 and MOST107-2119-M-002-035-MY3,and the Ministry of Education(Taiwan)Thailand Center of Excellence in PhysicsTUBITAK ULAKBIM(Turkey)Ministry of Education and Science of Ukrainethe US National Science Foundation and research grant Nos.PHY-1807007 and PHY-1913789the US Department of Energy and research grant Nos.DE-AC06-76RLO1830,DE-SC0007983,DE-SC0009824,DE-SC0009973,DE-SC0010073,DE-SC0010118,DE-SC0010504,DESC0011784,DE-SC0012704the National Foundation for Science and Technology Development(NAFOSTED)of Vietnam under grant No 103.99-2018.45
文摘From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.
基金Supported by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11125525,11235011,11322544,11335008,11425524)+5 种基金Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(11179007,U1232201,U1332201)CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(Collaborative Research Center CRC-1044),Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,University of Groningen(RUG)and the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt and WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.
基金Supported by the Ministry of Science and Technology of China(2009CB825204)National Natural Science Foundation of China(10625524,10821063,10825524,10835001,10935007,11125525,11235011)+7 种基金Joint Funds of the National Natural Science Foundation of China(11079008,11179007)Chinese Academy of Sciences Large-Scale Scientific Facility Program,CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,German Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823)U.S.National Science Foundation,University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI)Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘Data sets were collected with the BESⅢ detector at the BEPCⅡ collider at the center-of-mass energy of √s=3.650 GeV during May 2009 and at √s=3.773 GeV from January 2010 to May 2011. By analyzing the large angle Bhabha scattering events, the integrated luminosities of the two data sets are measured to be (44.49±0.02±0.44) pb-1 and (2916.94±0.18±29.17) pb-1, respectively, where the first error is statistical and the second error is systematic.