Studies of e+e?→D+sDˉˉˉˉ(?)0K?e+e?→Ds+Dˉ(?)0K?and the PP-wave charmed-strange mesons are performed based on an e+e?e+e?collision data sample corresponding to an integrated luminosity of 567 pb?1 collected with ...Studies of e+e?→D+sDˉˉˉˉ(?)0K?e+e?→Ds+Dˉ(?)0K?and the PP-wave charmed-strange mesons are performed based on an e+e?e+e?collision data sample corresponding to an integrated luminosity of 567 pb?1 collected with the BESIII detector at s√=4.600s=4.600 GeV.The processes of e+e?→D+sDˉˉˉˉ?0K?e+e?→Ds+Dˉ?0K?and D+sDˉˉˉˉ0K?Ds+Dˉ0K?are observed for the first time and are found to be dominated by the modes D+sDs1(2536)?Ds+Ds1(2536)?and D+sD?s2(2573)?Ds+Ds2?(2573)?,respectively.The Born cross sections are measured to beσB(e+e?→D+sDˉˉˉˉ?0K?)=(10.1±2.3±0.8)σB(e+e?→Ds+Dˉ?0K?)=(10.1±2.3±0.8)pb andσB(e+e?→D+sDˉˉˉˉ0K?)=(19.4±2.3±1.6)σB(e+e?→Ds+Dˉ0K?)=(19.4±2.3±1.6)pb,and the products of Born cross section and the decay branching fraction are measured to beσB(e+e?→D+sDs1(2536)?+c.c.)?σB(e+e?→Ds+Ds1(2536)?+c.c.)?B(Ds1(2536)?→Dˉˉˉˉ?0K?)=(7.5±1.8±0.7)B(Ds1(2536)?→Dˉ?0K?)=(7.5±1.8±0.7)pb andσB(e+e?→D+sD?s2(2573)?+c.c.)?B(D?s2(2573)?→Dˉˉˉˉ0K?)=σB(e+e?→Ds+Ds2?(2573)?+c.c.)?B(Ds2?(2573)?→Dˉ0K?)=(19.7±2.9±2.0)(19.7±2.9±2.0)pb.For the Ds1(2536)?Ds1(2536)?and D?s2(2573)?Ds2?(2573)?mesons,the masses and widths are measured to be M(Ds1(2536)?)=(2537.7±0.5±3.1)MeV/c2M(Ds1(2536)?)=(2537.7±0.5±3.1)MeV/c2,Γ(Ds1(2536)?)=(1.7±1.2±0.6)Γ(Ds1(2536)?)=(1.7±1.2±0.6)MeV,and M(D?s2(2573)?)=M(Ds2?(2573)?)=(2570.7±2.0±1.7)MeV/c2,(2570.7±2.0±1.7)MeV/c2,Γ(D?s2(2573)?)=(17.2±3.6±1.1)Γ(Ds2?(2573)?)=(17.2±3.6±1.1)MeV.The spin-parity of the D?s2(2573)?Ds2?(2573)?meson is determined to be JP=2+JP=2+.In addition,the processes e+e?→D+sDˉˉˉˉ(?)0K?e+e?→Ds+Dˉ(?)0K?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
We study the hadronic decays of ∧c^+ to the final states ∑^+η and ∑^+η, using an e^+e^- annihilation data sample of 567 pb^-1 taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII col...We study the hadronic decays of ∧c^+ to the final states ∑^+η and ∑^+η, using an e^+e^- annihilation data sample of 567 pb^-1 taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII collider. We find evidence for the decays ∧^+→∑^+η and ∑^+η' and with statistical significance of and , respectively. Normalizing to the reference decays ∧^+→∑^+π^0 and ∑^+ω, we obtain the ratios of the branching fractions B(∧C^+→∑^+η)/V(∧^→∑^+π^0)and B(∧C^+→∑^+η)/B(∧C^+→∑^+ω)to be and , respectively. The upper limits at the 90% confidence level are set to be B(∧C^→∑^+η)/V(∧^+→∑^+π^0)<0.58 and B(∧C^+→∑^+η)/B(∧C^+→∑^+ω)<1.2. Using BESIII measurements of the branching fractions of the reference decays, we determine B(∧C^+→∑^+η)=(0.41±019±0.05)%(<0.68%) and B(∧C^+→∑^+η)=(1.34+0.53+0.19)%(<1.9%). Here, the first uncertainties are statistical and the second systematic. The obtained branching fraction of ∧C^+→∑^+η is consistent with the previous measurement, and the branching fraction of ∧C^+→∑^+η is measured for the first time.展开更多
词句解析1. Could you please tell me where therestroom is?请你告诉我洗手间在哪儿好吗?"Could you please...?”意为“请你好吗?”,是表示请求的礼貌用语,后面接动词原形,其否定形式是在please后面加上not。could在此不表示过...词句解析1. Could you please tell me where therestroom is?请你告诉我洗手间在哪儿好吗?"Could you please...?”意为“请你好吗?”,是表示请求的礼貌用语,后面接动词原形,其否定形式是在please后面加上not。could在此不表示过去,而表示委婉语气。展开更多
词句解析1.What are the shirts made of?这些衬衫是用什么做的?be made of意为"由制成",成品中能看出原材料;be made from意为"由...制成”,成品中看不出原材料;bemadein意为“由(某地)制造^;be made by意为“由(某人)...词句解析1.What are the shirts made of?这些衬衫是用什么做的?be made of意为"由制成",成品中能看出原材料;be made from意为"由...制成”,成品中看不出原材料;bemadein意为“由(某地)制造^;be made by意为“由(某人)制造”。展开更多
each既可用作形容词,也可用作代词,意为“每个”,常指两个或两个以上的人或物中的每个。作形容词时,一般修饰单数名词;作代词时,常充当主语,此时谓语动词要用单数形式。例如:Each person has a dream.每个人都有一个梦想。Each of us ha...each既可用作形容词,也可用作代词,意为“每个”,常指两个或两个以上的人或物中的每个。作形容词时,一般修饰单数名词;作代词时,常充当主语,此时谓语动词要用单数形式。例如:Each person has a dream.每个人都有一个梦想。Each of us has a dictionary.我们每个人都有一本词典。展开更多
随着环形正负电子对撞机(Circular Electron Positron Collider,CEPC)方案的提出,由硅光电倍增管(Silicon Photomulfiplier,SiPM)和塑料闪烁体组成的读出单元作为电磁量能器的预研方案之一,逐渐成为研究热点。在探测器预研阶段需...随着环形正负电子对撞机(Circular Electron Positron Collider,CEPC)方案的提出,由硅光电倍增管(Silicon Photomulfiplier,SiPM)和塑料闪烁体组成的读出单元作为电磁量能器的预研方案之一,逐渐成为研究热点。在探测器预研阶段需要对读出单元性能进行充分研究,因此我们设计了一套自动化测试系统用于对读出单元进行测试、分析并改善其性能。利用DT5751波形采样插件、SiPM驱动电路板、步进电机、低压电源、继电器等完成硬件搭建,以LabVIEW为开发平台完成了软件的串行协议接口之间的通信,实现了读出单元的自动化测试,编写了相应的数据处理程序。在此基础上进行了SiPM刻度、闪烁体发光均匀性以及反射材料对光输出影响的研究。测试结果表明,ESR反射膜包裹的塑闪条具有最高的光输出,塑闪条耦合10um像素SiPM的光输出为耦合25岬像素SiPM的三分之一。展开更多
请同学们先试做以下两道中考题:1.—Frank,where is your father?—He isn’t at home now.He____ New York.A.has gone to B.has been to C.goes to(2017邵阳)2.Neither Jim nor Tom ___Australia before,but they know the countryver...请同学们先试做以下两道中考题:1.—Frank,where is your father?—He isn’t at home now.He____ New York.A.has gone to B.has been to C.goes to(2017邵阳)2.Neither Jim nor Tom ___Australia before,but they know the countryvery well.A.has gone to B.has been to C.have gone to D.have been to(2017泰州)以上两道题是考查同学们对'have/has been to...'和'have/has gone to...'句型结构的掌握情况。展开更多
such;so【练一练】用such和so填空。1.—Did you see the film last night?—Yes,I have never seen an exciting film before.2.We love to go to the country in spring as the flowers smellnice.3.We are interested in good things...such;so【练一练】用such和so填空。1.—Did you see the film last night?—Yes,I have never seen an exciting film before.2.We love to go to the country in spring as the flowers smellnice.3.We are interested in good things.4.There are many people in the hall.5.Don’t go out in cold weather.展开更多
语法是英语学习中不可或缺的一部分,同学们如果能熟练掌握语法知识,相信在考试中也会应对自如。下面就七年级上册的语法常考点,通过一些中考题进行链接、解析。【考点一】考查物主代词1.My grandma and grandpa are teachers.They both ...语法是英语学习中不可或缺的一部分,同学们如果能熟练掌握语法知识,相信在考试中也会应对自如。下面就七年级上册的语法常考点,通过一些中考题进行链接、解析。【考点一】考查物主代词1.My grandma and grandpa are teachers.They both like ___ students.A.her B.his C.theirs D.their(2016毕节)展开更多
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.
文摘Studies of e+e?→D+sDˉˉˉˉ(?)0K?e+e?→Ds+Dˉ(?)0K?and the PP-wave charmed-strange mesons are performed based on an e+e?e+e?collision data sample corresponding to an integrated luminosity of 567 pb?1 collected with the BESIII detector at s√=4.600s=4.600 GeV.The processes of e+e?→D+sDˉˉˉˉ?0K?e+e?→Ds+Dˉ?0K?and D+sDˉˉˉˉ0K?Ds+Dˉ0K?are observed for the first time and are found to be dominated by the modes D+sDs1(2536)?Ds+Ds1(2536)?and D+sD?s2(2573)?Ds+Ds2?(2573)?,respectively.The Born cross sections are measured to beσB(e+e?→D+sDˉˉˉˉ?0K?)=(10.1±2.3±0.8)σB(e+e?→Ds+Dˉ?0K?)=(10.1±2.3±0.8)pb andσB(e+e?→D+sDˉˉˉˉ0K?)=(19.4±2.3±1.6)σB(e+e?→Ds+Dˉ0K?)=(19.4±2.3±1.6)pb,and the products of Born cross section and the decay branching fraction are measured to beσB(e+e?→D+sDs1(2536)?+c.c.)?σB(e+e?→Ds+Ds1(2536)?+c.c.)?B(Ds1(2536)?→Dˉˉˉˉ?0K?)=(7.5±1.8±0.7)B(Ds1(2536)?→Dˉ?0K?)=(7.5±1.8±0.7)pb andσB(e+e?→D+sD?s2(2573)?+c.c.)?B(D?s2(2573)?→Dˉˉˉˉ0K?)=σB(e+e?→Ds+Ds2?(2573)?+c.c.)?B(Ds2?(2573)?→Dˉ0K?)=(19.7±2.9±2.0)(19.7±2.9±2.0)pb.For the Ds1(2536)?Ds1(2536)?and D?s2(2573)?Ds2?(2573)?mesons,the masses and widths are measured to be M(Ds1(2536)?)=(2537.7±0.5±3.1)MeV/c2M(Ds1(2536)?)=(2537.7±0.5±3.1)MeV/c2,Γ(Ds1(2536)?)=(1.7±1.2±0.6)Γ(Ds1(2536)?)=(1.7±1.2±0.6)MeV,and M(D?s2(2573)?)=M(Ds2?(2573)?)=(2570.7±2.0±1.7)MeV/c2,(2570.7±2.0±1.7)MeV/c2,Γ(D?s2(2573)?)=(17.2±3.6±1.1)Γ(Ds2?(2573)?)=(17.2±3.6±1.1)MeV.The spin-parity of the D?s2(2573)?Ds2?(2573)?meson is determined to be JP=2+JP=2+.In addition,the processes e+e?→D+sDˉˉˉˉ(?)0K?e+e?→Ds+Dˉ(?)0K?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National Key Basic Research Program of China (2015CB856700)National Natural Science Foundation of China (NSFC)(11235011,11275266,11335008,11425524,11625523,11635010)+16 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 (U1332201,U1532257,U1532258)CAS (KJCX2-YW-N29,KJCX2-YW-N45,QYZDJ-SSW-SLH003)100 Talents Program of CASNational 1000 Talents Program of ChinaINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG (Collaborative Research Center CRC 1044,FOR 2359)Istituto Nazionale di Fisica Nucleare,ItalyKoninklijke Nederlandse Akademie van Wetenschappen (KNAW)(530-4CDP03)Ministry of Development of Turkey (DPT2006K-120470)National Science and Technology fundThe Swedish Research CouncilU. S. Department of Energy under (DE-FG02-05ER41374,DE-SC-0010118,DE-SC-0010504,DE-SC-0012069)University of Groningen (RuG)the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI),DarmstadtWCU Program of National Research Foundation of Korea (R32-2008-000-10155-0).
文摘We study the hadronic decays of ∧c^+ to the final states ∑^+η and ∑^+η, using an e^+e^- annihilation data sample of 567 pb^-1 taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII collider. We find evidence for the decays ∧^+→∑^+η and ∑^+η' and with statistical significance of and , respectively. Normalizing to the reference decays ∧^+→∑^+π^0 and ∑^+ω, we obtain the ratios of the branching fractions B(∧C^+→∑^+η)/V(∧^→∑^+π^0)and B(∧C^+→∑^+η)/B(∧C^+→∑^+ω)to be and , respectively. The upper limits at the 90% confidence level are set to be B(∧C^→∑^+η)/V(∧^+→∑^+π^0)<0.58 and B(∧C^+→∑^+η)/B(∧C^+→∑^+ω)<1.2. Using BESIII measurements of the branching fractions of the reference decays, we determine B(∧C^+→∑^+η)=(0.41±019±0.05)%(<0.68%) and B(∧C^+→∑^+η)=(1.34+0.53+0.19)%(<1.9%). Here, the first uncertainties are statistical and the second systematic. The obtained branching fraction of ∧C^+→∑^+η is consistent with the previous measurement, and the branching fraction of ∧C^+→∑^+η is measured for the first time.
文摘词句解析1. Could you please tell me where therestroom is?请你告诉我洗手间在哪儿好吗?"Could you please...?”意为“请你好吗?”,是表示请求的礼貌用语,后面接动词原形,其否定形式是在please后面加上not。could在此不表示过去,而表示委婉语气。
文摘each既可用作形容词,也可用作代词,意为“每个”,常指两个或两个以上的人或物中的每个。作形容词时,一般修饰单数名词;作代词时,常充当主语,此时谓语动词要用单数形式。例如:Each person has a dream.每个人都有一个梦想。Each of us has a dictionary.我们每个人都有一本词典。
文摘随着环形正负电子对撞机(Circular Electron Positron Collider,CEPC)方案的提出,由硅光电倍增管(Silicon Photomulfiplier,SiPM)和塑料闪烁体组成的读出单元作为电磁量能器的预研方案之一,逐渐成为研究热点。在探测器预研阶段需要对读出单元性能进行充分研究,因此我们设计了一套自动化测试系统用于对读出单元进行测试、分析并改善其性能。利用DT5751波形采样插件、SiPM驱动电路板、步进电机、低压电源、继电器等完成硬件搭建,以LabVIEW为开发平台完成了软件的串行协议接口之间的通信,实现了读出单元的自动化测试,编写了相应的数据处理程序。在此基础上进行了SiPM刻度、闪烁体发光均匀性以及反射材料对光输出影响的研究。测试结果表明,ESR反射膜包裹的塑闪条具有最高的光输出,塑闪条耦合10um像素SiPM的光输出为耦合25岬像素SiPM的三分之一。
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 Program the 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 CAS National 1000 Talents Program of China 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(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)
基金Supported by National Key Basic Research Program of China(2015CB856700) National Natural Science Foundation of China(NSFC)(11235011,11335008,11425524,11625523,11635010)+13 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 CAS(U1332201,U1532257,U1532258) CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040) 100 Talents Program of CAS National 1000 Talents Program of China,INPAC Shanghai Key Laboratory for Particle Physics and Cosmology,German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359 Istituto 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 Council,U.S.Department of Energy(DEFG02-05ER41374,DE-SC-0010118,DE-SC-0010504,DE-SC-0012069) University of Groningen(RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI) Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘请同学们先试做以下两道中考题:1.—Frank,where is your father?—He isn’t at home now.He____ New York.A.has gone to B.has been to C.goes to(2017邵阳)2.Neither Jim nor Tom ___Australia before,but they know the countryvery well.A.has gone to B.has been to C.have gone to D.have been to(2017泰州)以上两道题是考查同学们对'have/has been to...'和'have/has gone to...'句型结构的掌握情况。
文摘such;so【练一练】用such和so填空。1.—Did you see the film last night?—Yes,I have never seen an exciting film before.2.We love to go to the country in spring as the flowers smellnice.3.We are interested in good things.4.There are many people in the hall.5.Don’t go out in cold weather.
文摘语法是英语学习中不可或缺的一部分,同学们如果能熟练掌握语法知识,相信在考试中也会应对自如。下面就七年级上册的语法常考点,通过一些中考题进行链接、解析。【考点一】考查物主代词1.My grandma and grandpa are teachers.They both like ___ students.A.her B.his C.theirs D.their(2016毕节)