Based on(10087±44)×106J/ψevents collected with the BESⅢdetector,we search for the lepton number violating decay J/ψ→K+K+e-e-+c.c.for the first time.The upper limit on the branching fractio...Based on(10087±44)×106J/ψevents collected with the BESⅢdetector,we search for the lepton number violating decay J/ψ→K+K+e-e-+c.c.for the first time.The upper limit on the branching fraction of this decay is set to 2.1×10-9at the 90%confidence level with a frequentist method.This is the first search for J/ψdecays with a lepton number change by two,offering valuable insights into the underlying physical processes.展开更多
By analyzingψ(3686)data sample containing(107.7±0.6)×106events taken with the BESIII detector at the BEPCII storage ring in 2009,theχ_(c 0)resonance parameters are precisely measured usingχ_(c 0,c 2)→...By analyzingψ(3686)data sample containing(107.7±0.6)×106events taken with the BESIII detector at the BEPCII storage ring in 2009,theχ_(c 0)resonance parameters are precisely measured usingχ_(c 0,c 2)→π+π−/K+K−events.The mass ofχ_(c 0)is determined to be M(χ_(c 0))=(3415.63±0.07±0.07±0.07)MeV/c2,and its full width is F(χ_(c 0))=(12.52±0.12±0.13)MeV,where the first uncertainty is statistical,the second systematic,and the third for mass comes fromχ_(c 2)mass uncertainty.These measurements improve the precision ofχ_(c 0)mass by a factor of four and width by one order of magnitude over the previous individual measurements,and significantly boost our knowledge about the charmonium spectrum.Together with additional(345.4±2.6)×106(3686)data events taken in 2012,the decay branching fractions ofχ_(c 0,c 2)→π+π−/K+K−are measured as well,with precision improved by a factor of three compared to previous measurements.Theseχ_(c 0)decay branching fractions provide important inputs for the study of glueballs.展开更多
Using 20.3 fb-1of e+e-annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D+→γe+ve.An upper limi...Using 20.3 fb-1of e+e-annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D+→γe+ve.An upper limit on its partial branching fraction for photon energies Eγ>10 MeV was determined to be 1.2×10-5at a 90%confidence level;this excludes most current theoretical predictions.A sophisticated deep learning approach,which includes thorough validation and is based on the Transformer architecture,was implemented to efficiently distinguish the signal from massive backgrounds.展开更多
Utilizing 4.5 fb-1ofe+e-annihilation data collected at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV by the BESIII detector at the BEPCII collider,we searched for singly Cabibbo-suppressed h...Utilizing 4.5 fb-1ofe+e-annihilation data collected at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV by the BESIII detector at the BEPCII collider,we searched for singly Cabibbo-suppressed hadronic decaysΛc+→Σ0K+π0andΛc+→Σ0K+π+π−and with a single-tag method.No significant signals were observed for both decays.The upper limits on the branching fractions at the 90%confidence level were determined to be 5.0×10-4for and forΛc+→Σ0K+π0and 6.5×10-4forΛc+→Σ0K+π+π−.展开更多
Lepton number violation decayω→π+π+e-e-+c.c.is searched for via J/ψ→ωηusing a data sample of(1.0087±0.0044)×1010J/ψevents collected via the BESIII detector at the BEPCII collider.No s...Lepton number violation decayω→π+π+e-e-+c.c.is searched for via J/ψ→ωηusing a data sample of(1.0087±0.0044)×1010J/ψevents collected via the BESIII detector at the BEPCII collider.No significant signal is observed,and the upper limit on the branching fraction ofω→π+π+e-e-+c.c.at the 90%confidence level is determined for the first time to be 2.8×10-6.展开更多
Using an electron-positron collision data sample corresponding to(1.0087±0.0044)×1010events collected using the BESIII detector at the BEPCII collider,we firstly search for the lepton number violation de...Using an electron-positron collision data sample corresponding to(1.0087±0.0044)×1010events collected using the BESIII detector at the BEPCII collider,we firstly search for the lepton number violation decayφ→π+π+e-e-via J/ψ→φη.No obviously signals are found.The upper limit on the branching fraction ofφ→π+π+e-e-is set to be 1.3×10-5at the 90%confidence level.展开更多
We search for the leptonic decay D+→e+νeusing an e+e-collision data sample with an integrated luminosity of 20.3 fb-1collected with the BESIII detector at a center-of-mass energy of 3.773 GeV.Significant si...We search for the leptonic decay D+→e+νeusing an e+e-collision data sample with an integrated luminosity of 20.3 fb-1collected with the BESIII detector at a center-of-mass energy of 3.773 GeV.Significant signal is not observed,and an upper limit on the branching fraction of D+→e+νeis set as 9.7×10-7,at a confidence level of 90%.Our upper limit is an order of magnitude smaller than the previous limit for this decay mode.展开更多
Based on a sample of 2.7x 109ψ(3686)events collected by the BESIII detector operating at the BEP-CII collider,the decay 4(3686)→YXcJ,XcJ→ηηη’is analyzed.The decay modes Xc1and Xc2→ηηη’are ob...Based on a sample of 2.7x 109ψ(3686)events collected by the BESIII detector operating at the BEP-CII collider,the decay 4(3686)→YXcJ,XcJ→ηηη’is analyzed.The decay modes Xc1and Xc2→ηηη’are observed for the first time,and their corresponding branching fractions are determined to be B(Xc1→ηηη’)=(1.40±0.13(stat.)±0.09(sys.))×10-4and B(Xc2→ηηη’)=(4.18±0.84(stat.)±0.48(sys.))×10-5.An upper limit on the branching fraction of xco→ηηη’is set as 2.59×10-5at a 90%confidence level(CL).A partial wave analys-is(PWA)of the decay Xc1→ηηη’is performed to search for the 1-+exotic stateη1(1855).The PWA result indic-ates that the structure in theηη’mass spectrum is attributed to f0(1500),while in the m mass spectrum,it is attrib-uted to the 0++phase space.The upper limit of B(xcl→η1(1855)η)·B(η1(1855)→ηη')<9.79×10-5is set based on the PWA at 90%CL.展开更多
The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the ...The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.展开更多
Studies of e^+e~→D_s^+■(*0)K^-and the P-wave charmed-strange mesons are performed based on an e^+e^-collision data sample corresponding to an integrated luminosity of 567 pb-1 collected with the BESIII detecto...Studies of e^+e~→D_s^+■(*0)K^-and the P-wave charmed-strange mesons are performed based on an e^+e^-collision data sample corresponding to an integrated luminosity of 567 pb-1 collected with the BESIII detector at s1/2=4.600 GeV. The processes of e^+e^-→D_s^+■*0K^- and D_s^+■~0K^- are observed for the first time and are found to be dominated by the modes D_s^+Ds1(2536)^-and D_s^+Ds2~*(2573)^-, respectively. The Born cross sections are measured to be σ~B(e^+e^-→D_s^+■*0K^-) =(10.1±2.3±0.8) pb and σ~B(e^+e^-→D_s^+■~0K^-) =(19.4±2.3± 1.6) pb, and the products of Born cross section and the decay branching fraction are measured to be σ~B(e^+e^-→D_s^+Ds1(2536)^-+c.c.)·B(Ds1(2536)^-→■*0K^-)=(7.5±1.8±0.7) pb and σ~B(e^+e^-→D_s^+Ds2~*(2573)^-+ c.c.)·B(Ds2~*(2573)^-→■~0 K^-)=(19.7 ± 2.9 ±2.0) pb. For the Ds1(2536)^-and Ds2~*(2573)^-mesons, the masses and widths are measured to be M(Ds1(2536)^-)=(2537.7±0.5 ±3.1) MeV/c2, Γ(Ds1(2536)^-) =(1.7 ±1.2 ±0.6)MeV, and M(Ds2~*(2573)^-)=(2570.7±2.0 ±1.7) MeV/c^2, Γ(Ds2~*(2573)^-)=(17.2 ±3.6 ±1.1) MeV. The spin-parity of the Ds2~*(2573)^-meson is determined to be J^p= 2^+. In addition, the processes e^+e^-→D_s^+■(*0)K^-are searched for using the data samples taken at four(two) center-of-mass energies between 4.416(4.527) and 4.575 GeV, and upper limits at the 90% confidence level on the cross sections are determined.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(448.1±2.9)×106ψ(3686)for the weak baryonic decayψ(3686)→Λc+∑-+c.c..The analysis procedure is optimized using a blinded method.No significant signal is observed,and the upper limit on the branch...Using(448.1±2.9)×106ψ(3686)for the weak baryonic decayψ(3686)→Λc+∑-+c.c..The analysis procedure is optimized using a blinded method.No significant signal is observed,and the upper limit on the branching fraction(B)ofψ(3686)→Λc+∑-+c.c.is set as 1.4×10-5at the 90%confidence level.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 BESⅢand B facto...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 BESⅢand 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 BESⅢduring 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 BEPCⅡto higher luminosity.展开更多
Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,na...Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.展开更多
The integrated luminosities of data samples collected in the BESⅢexperiment in 2016-2017 at centerof-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1%by analyzing large-angle Bhabha...The integrated luminosities of data samples collected in the BESⅢexperiment in 2016-2017 at centerof-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1%by analyzing large-angle Bhabha scattering events.The integrated luminosities of old datasets collected in 2010-2014 are updated by considering corrections related to detector performance,offsetting the effect of newly discovered readout errors in the electromagnetic calorimeter,which can haphazardly occur.展开更多
The cross sections of e+e-→K+K-J/Ψat center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb-1data collected with the BESⅢdetector operating at the BEPCⅡstorage ring.Two resonant ...The cross sections of e+e-→K+K-J/Ψat center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb-1data collected with the BESⅢdetector operating at the BEPCⅡstorage ring.Two resonant structures are observed in the line shape of the cross sections.The mass and width of the first structure are measured to be(4225.3±2.3±21.5)MeV and(72.9±6.1±30.8)MeV,respectively.They are consistent with those of the established Y(4230).The second structure is observed for the first time with a statistical significance greater than 8σ,denoted as Y(4500).Its mass and width are determined to be(4484.7±13.3±24.1)MeV and(111.1±30.1±15.2)MeV,respectively.The first presented uncertainties are statistical and the second ones are systematic.The product of the electronic partial width with the decay branching fractionΓ(Y(4230)→e+e−)B(Y(4230)→K+K−J/Ψ)is reported.展开更多
During the 2016-17 and 2018-19 running periods,the BESIII experiment collected 7.5 fb of e+e-collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV.These data samples are primarily used for the ...During the 2016-17 and 2018-19 running periods,the BESIII experiment collected 7.5 fb of e+e-collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV.These data samples are primarily used for the study of excited charmonium and charmoniumlike states.By analyzing the di-muon process e+e-→(γISR=FSR)μ+μ-,we measure the center-of-mass energies of the data samples with a precision of 0.6 MeV.Through a run-by-run study,we find that the center-of-mass energies were stable throughout most of the data-collection period.展开更多
Data sets were collected with the BESⅢdetector at the BEPCⅡcollider 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 ...Data sets were collected with the BESⅢdetector at the BEPCⅡcollider 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
The decay channelψ′→π〉+π^-J/ψ(J/ψ〉γp^-p)is studied using a sample of 1.06×10^8ψ′events collected by the BESIII experiment at BEPCII.A strong enhancement at threshold is observed in the p^-p invariant ...The decay channelψ′→π〉+π^-J/ψ(J/ψ〉γp^-p)is studied using a sample of 1.06×10^8ψ′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 isГ〈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
The numbers ofψ(3686)events accumulated by the BESⅢdetector 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 had...The numbers ofψ(3686)events accumulated by the BESⅢdetector 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 ofψ(3686)events for the two data taking periods is(448.1±2.9)×10^6.展开更多
基金supported in part by National Key R&D Program of China under Contracts Nos.2023YFA1606000,2023YFA1606704National Natural Science Foundation of China(NSFC)under Contracts Nos.12035009,11635010,11935015,11935016,11935018,12025502,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramCAS under Contract No.YSBR-101100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG under Contract No.FOR5327Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation under Contracts Nos.2021.0174,2021.0299Ministry of Development of Turkey under Contract No.DPT2006K-120470National Research Foundation of Korea under Contract No.NRF-2022R1A2C1092335National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional DevelopmentResearch and Innovation of Thailand under Contract No.B50G670107Polish National Science Centre under Contract No.2024/53/B/ST2/00975Swedish Research Council under Contract No.2019.04595U.S.Department of Energy under Contract No.DE-FG02-05ER41374。
摘要Based on(10087±44)×106J/ψevents collected with the BESⅢdetector,we search for the lepton number violating decay J/ψ→K+K+e-e-+c.c.for the first time.The upper limit on the branching fraction of this decay is set to 2.1×10-9at the 90%confidence level with a frequentist method.This is the first search for J/ψdecays with a lepton number change by two,offering valuable insights into the underlying physical processes.
基金Supported in part by National Key R&D Program of China(2020YFA0406300,2020YFA0406400,2023YFA1606000)National Natural Science Foundation of China(NSFC)(11635010,11735014,11935015,11935016,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+17 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(U1832207)100 Talents Program of CAS(ZR2022JQ02,ZR2024QA151)supported by Shandong Provincial Natural Science Foundationsupported by the China Postdoctoral Science Foundation(2023M742100)The Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG(FOR5327,GRK 2149)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B16F640076,B50G670107)Polish National Science Centre(2019/35/O/ST2/02907)Swedish Research Council(2019.04595)The Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)U.S.Department of Energy(DE-FG02-05ER41374)。
摘要By analyzingψ(3686)data sample containing(107.7±0.6)×106events taken with the BESIII detector at the BEPCII storage ring in 2009,theχ_(c 0)resonance parameters are precisely measured usingχ_(c 0,c 2)→π+π−/K+K−events.The mass ofχ_(c 0)is determined to be M(χ_(c 0))=(3415.63±0.07±0.07±0.07)MeV/c2,and its full width is F(χ_(c 0))=(12.52±0.12±0.13)MeV,where the first uncertainty is statistical,the second systematic,and the third for mass comes fromχ_(c 2)mass uncertainty.These measurements improve the precision ofχ_(c 0)mass by a factor of four and width by one order of magnitude over the previous individual measurements,and significantly boost our knowledge about the charmonium spectrum.Together with additional(345.4±2.6)×106(3686)data events taken in 2012,the decay branching fractions ofχ_(c 0,c 2)→π+π−/K+K−are measured as well,with precision improved by a factor of three compared to previous measurements.Theseχ_(c 0)decay branching fractions provide important inputs for the study of glueballs.
基金supported in part by National Key R&D Program of China(2020YFA0406400,2023YFA1606000,2020YFA0406300)National Natural Science Foundation of China(NSFC)(11635010,11735014,11935015,11935016,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+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(U1832207)CAS(YSBR-101)100 Talents Program of CASCAS Project for Young Scientists in Basic Research(YSBR-117)The Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyAgencia Nacional de Investigación y Desarrollo de Chile(ANID),Chile(ANID PIA/APOYO AFB230003)German Research Foundation DFG(FOR5327)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B50G670107)Polish National Science Centre(2019/35/O/ST2/02907)Swedish Research Council(2019.04595)The Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)U.S.Department of Energy(DE-FG02-05ER41374)。
摘要Using 20.3 fb-1of e+e-annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D+→γe+ve.An upper limit on its partial branching fraction for photon energies Eγ>10 MeV was determined to be 1.2×10-5at a 90%confidence level;this excludes most current theoretical predictions.A sophisticated deep learning approach,which includes thorough validation and is based on the Transformer architecture,was implemented to efficiently distinguish the signal from massive backgrounds.
基金supported in part by National Key R&D Program of China(2020YFA0406300,2020YFA0406400,2023YFA1606000)National Natural Science Foundation of China(NSFC)(12205141,11635010,11735014,11935015,11935016,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+16 种基金Natural Science Foundation of Hunan Province(2024JJ2044)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(U1832207)100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG(FOR5327)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B16F640076,B50G670107)Polish National Science Centre(2019/35/O/ST2/02907)Swedish Research Council(2019.04595)The Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)U.S.Department of Energy(DE-FG02-05ER41374)。
摘要Utilizing 4.5 fb-1ofe+e-annihilation data collected at center-of-mass energies ranging from 4599.53 MeV to 4698.82 MeV by the BESIII detector at the BEPCII collider,we searched for singly Cabibbo-suppressed hadronic decaysΛc+→Σ0K+π0andΛc+→Σ0K+π+π−and with a single-tag method.No significant signals were observed for both decays.The upper limits on the branching fractions at the 90%confidence level were determined to be 5.0×10-4for and forΛc+→Σ0K+π0and 6.5×10-4forΛc+→Σ0K+π+π−.
基金Supported in part by National Key R&D Program of China(2023YFA1606000,2023YFA1606704)National Natural Science Foundation of China(NSFC)(12035009,11875170,11635010,11935015,11935016,11935018,12025502,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+16 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,CAS(YSBR-101)100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)Shanghai Key Laboratory for Particle Physics and CosmologyAgencia Nacional de Investigación y Desarrollo de Chile(ANID)Chile(ANID PIA/APOYO AFB230003)ERC(758462)German Research Foundation DFG(FOR5327)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaPolish National Science Centre(2024/53/B/ST2/00975)STFC(United Kingdom)Swedish Research Council(2019.04595)U.S.Department of Energy(DE-FG02-05ER41374)。
摘要Lepton number violation decayω→π+π+e-e-+c.c.is searched for via J/ψ→ωηusing a data sample of(1.0087±0.0044)×1010J/ψevents collected via the BESIII detector at the BEPCII collider.No significant signal is observed,and the upper limit on the branching fraction ofω→π+π+e-e-+c.c.at the 90%confidence level is determined for the first time to be 2.8×10-6.
基金supported in part by the National Key R&D Program of China(2020YFA0406300,2020YFA0406400)National Natural Science Foundation of China(NSFC)(12035009,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12025502,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017)+17 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(U1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASthe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and Cosmologythe European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement(894790)the German Research Foundation DFG(455635585),the Collaborative Research Center CRC 1044,FOR5327,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF2022R1A2C1092335)National Science and Technology Fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B16F640076)Polish National Science Centre(2019/35/O/ST2/02907)Swedish Research Council(2019.04595)the Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)the U.S.Department of Energy(DE-FG02-05ER41374).
摘要Using an electron-positron collision data sample corresponding to(1.0087±0.0044)×1010events collected using the BESIII detector at the BEPCII collider,we firstly search for the lepton number violation decayφ→π+π+e-e-via J/ψ→φη.No obviously signals are found.The upper limit on the branching fraction ofφ→π+π+e-e-is set to be 1.3×10-5at the 90%confidence level.
基金Supported in part by the National Key R&D Program of China(2023YFA1606000,2020YFA0406400,2020YFA0406300)the National Natural Science Foundation of China(NSFC)(11635010,11735014,11935015,11935016,11875054,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+12 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics(CCEPP)the Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U2032104,U1832207)the 100 Talents Program of CAS,the Excellent Youth Foundation of Henan Scientific Commitee(242300421044)the Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and Cosmology,the German Research Foundation DFG(FOR5327)the Istituto Nazionale di Fisica Nucleare,Italy,the Knut and Alice Wallenberg Foundation(2021.0174,2021.0299)the Ministry of Development of Turkey(DPT2006K-120470),the National Research Foundation of Korea(NRF-2022R1A2C1092335)the National Science and Technology Fund of Mongoliathe National Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research,and Innovation of Thailand(B16F640076,B50G670107)the Polish National Science Center(2019/35/O/ST2/02907)the Swedish Research Council(2019.04595)the Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)the US Department of Energy(DE-FG02-05ER41374)。
摘要We search for the leptonic decay D+→e+νeusing an e+e-collision data sample with an integrated luminosity of 20.3 fb-1collected with the BESIII detector at a center-of-mass energy of 3.773 GeV.Significant signal is not observed,and an upper limit on the branching fraction of D+→e+νeis set as 9.7×10-7,at a confidence level of 90%.Our upper limit is an order of magnitude smaller than the previous limit for this decay mode.
基金National Key R&D Program of China(2023YFA1606000,2023YFA1606704)National Natural Science Foundation of China(NSFC)(11635010,11935015,11935016,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+14 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramCAS(YSBR-101)100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyAgencia Nacional de Investigación y Desarrollo de Chile(ANID),Chile(ANID PIA/APOYO AFB230003)German Research Foundation DFG(FOR5327)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources Institutional Development,Research and Innovation of Thailand(B50G670107)Polish National Science Centre(2024/53/B/ST2/00975)Swedish Research Council(2019.04595)U.S.Department of Energy(DE-FG02-05ER41374)。
摘要Based on a sample of 2.7x 109ψ(3686)events collected by the BESIII detector operating at the BEP-CII collider,the decay 4(3686)→YXcJ,XcJ→ηηη’is analyzed.The decay modes Xc1and Xc2→ηηη’are observed for the first time,and their corresponding branching fractions are determined to be B(Xc1→ηηη’)=(1.40±0.13(stat.)±0.09(sys.))×10-4and B(Xc2→ηηη’)=(4.18±0.84(stat.)±0.48(sys.))×10-5.An upper limit on the branching fraction of xco→ηηη’is set as 2.59×10-5at a 90%confidence level(CL).A partial wave analys-is(PWA)of the decay Xc1→ηηη’is performed to search for the 1-+exotic stateη1(1855).The PWA result indic-ates that the structure in theηη’mass spectrum is attributed to f0(1500),while in the m mass spectrum,it is attrib-uted to the 0++phase space.The upper limit of B(xcl→η1(1855)η)·B(η1(1855)→ηη')<9.79×10-5is set based on the PWA at 90%CL.
基金supported in part by National Key R&D Program of China under Contracts Nos.2020YFA0406300,2020YFA0406400National Natural Science Foundation of China(NSFC)under Contracts Nos.12150004,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017+17 种基金the Program of Science and Technology Development Plan of Jilin Province of China under Contract Nos.20210508047RQ and 20230101021JCthe 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 under Contract No.U1832207CAS Key Research Program of Frontier Sciences under Contracts Nos.QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)Shanghai Key Laboratory for Particle Physics and CosmologyEuropean Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement under Contract No.894790German Research Foundation DFG under Contracts Nos.455635585,Collaborative Research Center CRC 1044,FOR5327,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey under Contract No.DPT2006K-120470National Research Foundation of Korea under Contract No.NRF-2022R1A2C1092335National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand under Contract No.B16F640076Polish National Science Centre under Contract No.2019/35/O/ST2/02907The Swedish Research CouncilU.S.Department of Energy under Contract No.DE-FG02-05ER41374。
摘要The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.
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)+9 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,the 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 Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC,Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,Italy,Koninklijke Nederlandse Akademie van Wetenschappen(KNAW)(530-4CDP03)Ministry of Development of Turkey(DPT2006K-120470)National Science and Technology fund,The Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374,DE-SC-0010118,DE-SC-0010504,DE-SC-0012069),University of Groningen(RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt
摘要Studies of e^+e~→D_s^+■(*0)K^-and the P-wave charmed-strange mesons are performed based on an e^+e^-collision data sample corresponding to an integrated luminosity of 567 pb-1 collected with the BESIII detector at s1/2=4.600 GeV. The processes of e^+e^-→D_s^+■*0K^- and D_s^+■~0K^- are observed for the first time and are found to be dominated by the modes D_s^+Ds1(2536)^-and D_s^+Ds2~*(2573)^-, respectively. The Born cross sections are measured to be σ~B(e^+e^-→D_s^+■*0K^-) =(10.1±2.3±0.8) pb and σ~B(e^+e^-→D_s^+■~0K^-) =(19.4±2.3± 1.6) pb, and the products of Born cross section and the decay branching fraction are measured to be σ~B(e^+e^-→D_s^+Ds1(2536)^-+c.c.)·B(Ds1(2536)^-→■*0K^-)=(7.5±1.8±0.7) pb and σ~B(e^+e^-→D_s^+Ds2~*(2573)^-+ c.c.)·B(Ds2~*(2573)^-→■~0 K^-)=(19.7 ± 2.9 ±2.0) pb. For the Ds1(2536)^-and Ds2~*(2573)^-mesons, the masses and widths are measured to be M(Ds1(2536)^-)=(2537.7±0.5 ±3.1) MeV/c2, Γ(Ds1(2536)^-) =(1.7 ±1.2 ±0.6)MeV, and M(Ds2~*(2573)^-)=(2570.7±2.0 ±1.7) MeV/c^2, Γ(Ds2~*(2573)^-)=(17.2 ±3.6 ±1.1) MeV. The spin-parity of the Ds2~*(2573)^-meson is determined to be J^p= 2^+. In addition, the processes e^+e^-→D_s^+■(*0)K^-are searched for using the data samples taken at four(two) center-of-mass energies between 4.416(4.527) and 4.575 GeV, and upper limits at the 90% confidence level on the cross sections are determined.
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)。
摘要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 Research and Development Program of China(2020YFA0406400,2020YFA0406300)National Natural Science Foundation of China(NSFC,11975118,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12022510,12025502,12035009,12035013,12192260,12192261,12192262,12192263,12192264,12192265,12061131003)+18 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(U1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH040)100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and Cosmology,ERC(758462)European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement(894790)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 and Institutional Development,Research and Innovation(B16F640076)STFC(United Kingdom)Suranaree University of Technology(SUT),Thailand Science Research and Innovation(TSRI),and National Science Research and Innovation Fund(NSRF,160355)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374)。
摘要Using(448.1±2.9)×106ψ(3686)for the weak baryonic decayψ(3686)→Λc+∑-+c.c..The analysis procedure is optimized using a blinded method.No significant signal is observed,and the upper limit on the branching fraction(B)ofψ(3686)→Λc+∑-+c.c.is set as 1.4×10-5at the 90%confidence level.
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).
摘要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 BESⅢand 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 BESⅢduring 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 BEPCⅡto higher luminosity.
基金Supported in part by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012)+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U 1732263,U 1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSWSLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development o f 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(DEFG02-05ER41374,DE-SC-0012069)。
摘要Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.
基金Supported in part by National Key R&D Program of China(2020YFA0406300,2020YFA0406400)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012,12022510,12025502,12035009,12035013,12061131003)+16 种基金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(Marie Sklodowska-Curie grant agreement No 894790)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 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)。
摘要The integrated luminosities of data samples collected in the BESⅢexperiment in 2016-2017 at centerof-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1%by analyzing large-angle Bhabha scattering events.The integrated luminosities of old datasets collected in 2010-2014 are updated by considering corrections related to detector performance,offsetting the effect of newly discovered readout errors in the electromagnetic calorimeter,which can haphazardly occur.
基金Supported in part by National Key R&D Program of China(2020YFA0406300,2020YFA0406400)National Natural Science Foundation of China(NSFC)under Contracts Nos.(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012,12022510,12025502,12035009,12035013,12061131003)+16 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts Nos.(U1732263,U1832207)CAS Key Research Program of Frontier Sciences under Contract No.(QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC under Contract No.(758462)European Union Horizon 2020 research and innovation programme under Contract No.Marie Sklodowska-Curie grant agreement No(894790)German Research Foundation DFG under Contracts Nos.(443159800),Collaborative Research Center CRC 1044,FOR 2359,GRK 214Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey under Contract No.(DPT2006K-120470)National Science and Technology fundOlle Engkvist Foundation under Contract No.(200-0605)STFC(United Kingdom)The Knut and Alice Wallenberg Foundation(Sweden)under Contract No.(2016.0157)The Royal Society,UK under Contracts Nos.(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy under Contracts Nos.(DE-FG02-05ER41374,DE-SC-001206)。
摘要The cross sections of e+e-→K+K-J/Ψat center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb-1data collected with the BESⅢdetector operating at the BEPCⅡstorage ring.Two resonant structures are observed in the line shape of the cross sections.The mass and width of the first structure are measured to be(4225.3±2.3±21.5)MeV and(72.9±6.1±30.8)MeV,respectively.They are consistent with those of the established Y(4230).The second structure is observed for the first time with a statistical significance greater than 8σ,denoted as Y(4500).Its mass and width are determined to be(4484.7±13.3±24.1)MeV and(111.1±30.1±15.2)MeV,respectively.The first presented uncertainties are statistical and the second ones are systematic.The product of the electronic partial width with the decay branching fractionΓ(Y(4230)→e+e−)B(Y(4230)→K+K−J/Ψ)is reported.
基金Supported in part by National Key Research and Development Program of China(2020YFA0406300,2020YFA0406400)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012)+12 种基金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-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CAS,INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology,ERC(758462)European Union Horizon 2020 research and innovation programme(Marie Sklodowska-Curie grant agreement No 894790)German Research Foundation DFG(443159800)Collaborative Research Center CRC 1044,FOR 2359,FOR 2359,GRK 214Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)National Science and Technology fund,Olle 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 Council,U.S.Department of Energy(DE-FG02-05ER41374,DE-SC-0012069)。
摘要During the 2016-17 and 2018-19 running periods,the BESIII experiment collected 7.5 fb of e+e-collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV.These data samples are primarily used for the study of excited charmonium and charmoniumlike states.By analyzing the di-muon process e+e-→(γISR=FSR)μ+μ-,we measure the center-of-mass energies of the data samples with a precision of 0.6 MeV.Through a run-by-run study,we find that the center-of-mass energies were stable throughout most of the data-collection period.
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)
摘要Data sets were collected with the BESⅢdetector at the BEPCⅡcollider 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.
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
摘要The decay channelψ′→π〉+π^-J/ψ(J/ψ〉γp^-p)is studied using a sample of 1.06×10^8ψ′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 isГ〈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 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)
摘要The numbers ofψ(3686)events accumulated by the BESⅢdetector 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 ofψ(3686)events for the two data taking periods is(448.1±2.9)×10^6.