A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of t...A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of the penetration process.A numerical tool using AUTODYN hydrocode is applied in the study.The numerical results on both deceleration-time history and depth of penetration of projectiles are in good agreement with experimental data,which demonstrate the feasibility of the numerical model in these conditions.Based on the numerical model with a two-staged pre-drilled hole,the rigid projectile penetration in tunneling stage is studied for concrete targets with different strengths in a wide range of impact velocities.The results show that the penetration in tunnel stage can be divided into two different cases in terms of initial impact velocity.In the first case,when the impact velocity is approximately less than 600 m/s,the deceleration depends on initial impact velocity.In the second case,when the impact velocity is greater than 600 m/s,the effect of target inertia becomes apparent,which agrees with commonly used concrete penetration resistance equations based on cavity expansion model.展开更多
Similarity can reflect common laws in the mechanism of rigid-body penetration.In this paper,the similarities in rigid-body penetration depth are demonstrated by three non-dimensional but physically meaningful quantiti...Similarity can reflect common laws in the mechanism of rigid-body penetration.In this paper,the similarities in rigid-body penetration depth are demonstrated by three non-dimensional but physically meaningful quantities,i.e.,ρkinetic,I∗ln and N′1.These three quantities represent the non-dimensional areal density of projectile kinetic energy,the effect of nose geometry,and the friction at the interactive cross section between projectile and target respectively.It is shown that experimental data of rigid projectile penetration,from shallow to deep penetration,can be uniquely unified by these three similarity quantities and their relationships.Furthermore,for ogival nose projectiles,their penetration capacities are dominated byρkinetic,which is consisted by non-dimensional effective length Leff and non-dimensional quantity Dpn=ρpv20AY which has the same form as Johnson’s damage number.On the sacrifice of minor theoretical accuracy,the non-dimensional penetration depth P/d can be understood as directly controlled by Dpn,enhanced by projectile effective length Leff under a multiplication relation,and optimized by projectile nose geometry in the formation of I∗ln.展开更多
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
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
We present a measurement of the integrated luminosity of e+e-collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the ...We present a measurement of the integrated luminosity of e+e-collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1,8.157±0.031 fb-1,and 4.191±0.016 fb-1,respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.展开更多
Using e+e−annihilation data corresponding to an integrated luminosity of 2.93 fb−1taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays...Using e+e−annihilation data corresponding to an integrated luminosity of 2.93 fb−1taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D0→π+π−π+π−and D0→π+π−π0π0(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D0→a1(1260)π,D0→π(1300)π,D0→ρ(770)ρ(770),and D0→2(ππ)Sare observed in both channels.With the obtained amplitude model,the CP-even fractions of D0→π+π−π+π−and D0→π+π−π0π0(non-η)are determined to be(75.2±1.1stat.±1.5syst.)%and(68.9±1.5stat.±2.4syst.)%,respectively.The branching fractions of D0→π+π−π+π−and D0→π+π−π0π0(non-η)are measured to be(0.688±0.010stat.±0.010syst.)%and(0.951±0.025stat.±0.021syst.)%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D0→4πwhen used to determine the CKM angleγ(ϕ3)via the B−→DK−decay.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant 11390362)the Young Foundation of Shanxi University of Finance and Economics(Grant Z06134).
摘要A study on the resistance of rigid projectiles penetrating into semi-infinite concrete targets is performed in this paper.Experimental data are analyzed to examine the penetration resistance during various stages of the penetration process.A numerical tool using AUTODYN hydrocode is applied in the study.The numerical results on both deceleration-time history and depth of penetration of projectiles are in good agreement with experimental data,which demonstrate the feasibility of the numerical model in these conditions.Based on the numerical model with a two-staged pre-drilled hole,the rigid projectile penetration in tunneling stage is studied for concrete targets with different strengths in a wide range of impact velocities.The results show that the penetration in tunnel stage can be divided into two different cases in terms of initial impact velocity.In the first case,when the impact velocity is approximately less than 600 m/s,the deceleration depends on initial impact velocity.In the second case,when the impact velocity is greater than 600 m/s,the effect of target inertia becomes apparent,which agrees with commonly used concrete penetration resistance equations based on cavity expansion model.
基金The first author would like to acknowledge the scholarship granted by the China Scholarship Council and the support from the Institute of Chemical Materials,CAEP.The authors greatly appreciate financial support from the National Natural Science Foundation of China(Grants 11702266,11972329,51703211,and 11902301).
摘要Similarity can reflect common laws in the mechanism of rigid-body penetration.In this paper,the similarities in rigid-body penetration depth are demonstrated by three non-dimensional but physically meaningful quantities,i.e.,ρkinetic,I∗ln and N′1.These three quantities represent the non-dimensional areal density of projectile kinetic energy,the effect of nose geometry,and the friction at the interactive cross section between projectile and target respectively.It is shown that experimental data of rigid projectile penetration,from shallow to deep penetration,can be uniquely unified by these three similarity quantities and their relationships.Furthermore,for ogival nose projectiles,their penetration capacities are dominated byρkinetic,which is consisted by non-dimensional effective length Leff and non-dimensional quantity Dpn=ρpv20AY which has the same form as Johnson’s damage number.On the sacrifice of minor theoretical accuracy,the non-dimensional penetration depth P/d can be understood as directly controlled by Dpn,enhanced by projectile effective length Leff under a multiplication relation,and optimized by projectile nose geometry in the formation of I∗ln.
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(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 the National Key R&D Program of China(2020YFA0406400,2020YFA0406300,2023YFA1606000)the National Natural Science Foundation of China(123B2077,12035009,11635010,11735014,11875054,11935015,11935016,11935018,11961141012,12025502,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+8 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,the CAS Center for Excellence in Particle Physics(CCEPP),the Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U2032104,U1832207)the Excellent Youth Foundation of Henan Scientific Commitee(242300421044)100 Talents Program of CASthe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG(455635585,FOR5327,GRK 2149)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of Mongolia,National 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),the Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374)。
摘要We present a measurement of the integrated luminosity of e+e-collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1,8.157±0.031 fb-1,and 4.191±0.016 fb-1,respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.
基金Supported in part by the National Key R&D Program of China(2020YFA0406300,2020YFA0406400)the National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12025502,12035009,12035013,12061131003,12105276,12122509,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017)+15 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(U1732263,U1832103,U1832207,U2032111)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 CosmologyEuropean Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement(894790)German Research Foundation DFG(455635585),Collaborative Research Center CRC 1044,FOR5327,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry 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)Polish National Science Centre(2019/35/O/ST2/02907)The Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374)。
摘要Using e+e−annihilation data corresponding to an integrated luminosity of 2.93 fb−1taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D0→π+π−π+π−and D0→π+π−π0π0(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D0→a1(1260)π,D0→π(1300)π,D0→ρ(770)ρ(770),and D0→2(ππ)Sare observed in both channels.With the obtained amplitude model,the CP-even fractions of D0→π+π−π+π−and D0→π+π−π0π0(non-η)are determined to be(75.2±1.1stat.±1.5syst.)%and(68.9±1.5stat.±2.4syst.)%,respectively.The branching fractions of D0→π+π−π+π−and D0→π+π−π0π0(non-η)are measured to be(0.688±0.010stat.±0.010syst.)%and(0.951±0.025stat.±0.021syst.)%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D0→4πwhen used to determine the CKM angleγ(ϕ3)via the B−→DK−decay.