6533b832fe1ef96bd129ab77

RESEARCH PRODUCT

Precision Measurement of the e+e−→Λc+Λ¯c− Cross Section Near Threshold

A. G. DenigC. L. LuoQ. ZhouI. TapanY. H. YanZ. T. SunC. C. ZhangB. ZhongW. G. LiY. K. SunH. MuramatsuA. N. ZhuUlrich WiednerJ. W. ZhaoJ. LibbyQ. P. JiS. SpataroX. P. XuM. KornicerM. Y. DongY. C. ZhuYaquan FangXianglei ZhuY. BanT. MaF. De MoriP. WeidenkaffF. H. HeinsiusA. PitkaL. J. WuXu ShanLei LiMeng WangX. Y. ZhouS. P. WenE. BogerH. B. LiuT. HeldI. B. NikolaevX. R. ZhouK. SchoenningQ. Y. LiB. S. ZouY. J. MoG. F. CaoJ. H. YinCheng LiM. ShaoY. T. GuJ. H. ZouNiklaus BergerQ. A. MalikG. MezzadriJ. MinX. Q. HeX. F. WangL. KochA. KhoukazX. Y. JiangE. FioravantiZhiqing LiuS. S. SunR. Baldini FerroliX. K. ChuY. H. ZhengJ. C. LiCong-feng QiaoK. J. LiL. P. ZhouQ. M. MaA. MustafaN. Yu. MuchnoiA. Q. GuoZ. Y. PengG. RongX. S. KangZ. X. MengX. A. XiongY. H. ZhangB. KopfY. M. MaXiao-rui LyuA. SarantsevD. H. WeiP. R. LiP. R. LiJ. S. LangeH. R. QiJ. ZhuangLei ZhangZ. P. MaoZ. Y. WangT. JohanssonMichael PapenbrockX. S. QinF. YanM. X. LuoJ. F. SunJ. FangA. A. ZafarBingxuan LiuJ. F. ChangP. L. WangD. V. DedovichK. L. HeT. HoltmannK. GoetzenY. YuanY. S. ZhuY. G. GaoYu ZhangQ. P. JiY. H. XieJ. PellegrinoM. H. YeS. JinXuesong LiuZ. GaoX. N. LiYao ZhangG. LiG. S. VarnerZhiyong ZhangK. H. RashidM. Z. WangX. Y. NiuSerkant Ali CetinJimin ZhaoM. AlbrechtJ. Y. LiuZahra HaddadiHaiping PengR. E. MitchellQ. LiuL. D. LiuW. P. WangL. Y. DongCh. RosnerZ. H. QinS. MarcelloA. GilmanM. MaggioraO. B. KolcuX. CaiKai LiuW. D. LiKe WangLing ZhaoW. M. SongLei ZhaoLiqing XuY. T. LiangX. Y. ShenL. L. MaL. GongF. A. HarrisY. ZengC. D. FuC. Q. FengA. CalcaterraZ. G. ZhaoS. FeganF. NerlingX D ShiY. PanJ. H. WeiY. J. MaoL. LavezziT. KhanM. BertaniS. J. ChenX. R. ChenJ. ChaiZ. J. XiaoL. YangZ. L. HouB. T. TsedneeA. AmorosoZ. Y. DengH. LeithoffH. X. YangH. H. ZhangG. X. SunJ. V. BennettI. GarziaJ. L. ZhangM. H. GuH. LiangX. Q. HaoX. K. ZhouFang LiuS. LussoP. F. DuanS. QianV. PrasadZ. J. SunXingguo LiJiangbo ZhuY. NefedovJialun PingZ. JiaoFu-hu LiuD. H. ZhangS. HanYi-tao WangY. DingMinglin MaK. ZhangA. DbeyssiX. H. MoL. S. WangM. H. YeH. Y. ShengFenfen AnB. L. WangX. Y. ZhangM. FritschJ. Z. BaiS. J. ZhaoQ. GaoF. LiF. C. MaL. H. WuY. N. GaoX. L. JiJun-yi ZhangB. J. LiuL. L. WangY. T. TanW. GradlQ. AnB. GarillonHuihui LiuH. CaiM. LaraJ. B. LiuX. TangT. Y. QiM. RipkaC. X. YuT. C. ZhaoI. DenysenkoW. C. YanJianhao ZhangY. P. GuoKe LiuM. SavrieY. J. SunYifan YangJ. S. HuangC. Z. YuanM. KuhlmannYi JinA. JulinD. Y. WangJ. G. MesschendorpZ. P. ZhangJ. P. DaiC. X. LiuW. KühnQiunan XuZ. Y. YouZ. A. ZhuB. ZhengR. G. PingY. P. LuY. B. ChenJ. Z. ZhangJ. W. LiJ. F. QiuCui LiS. AhmedY. X. YangL. XiaY. J. XiaoKang LiM. QiMagnus WolkeH. J. YangP. L. ChenZhuoming LiD. W. BennettZujian WangX. B. JiM. TiemensP. PatteriD. Y. LiuH. J. LuT. WeberJ. G. LuB. Y. ZhangL. FavaY. BaiJ. B. JiaoJ. J. SongY. F. LiangD. P. JinG. F. XuQ. J. XuYuekun HengB. X. YuZhi ZengF. FeldbauerY. G. XieZ. L. HuangQ. ZhaoY. Z. SunGuangshun HuangL. YanR. KliemtS. Q. ZhangC. P. ShenL. SunA. YuncuM. RoloXiang ZhouF. E. MaasDayong WangN. QinC. SowaY. B. ZhaoJ. C. ChenXuanhong LouS. X. DuC. X. LinT. HuYang ZhangC. F. RedmerJ. F. HuXiaozhong HuangX. Y. SongH. S. ChenGang ZhaoY. X. XiaS. H. ZhuA. GuskovZ. L. DouJ. DongJie YuC. SchnierFeng LiuM. AblikimG. A. ChelkovNasser Kalantar-nayestanakiX. T. HuangY. ZhangH. L. DaiIgor BoykoO. BakinaS. B. LiuR. FarinelliY. Q. WangS. NisarAndrzej KupscH. L. MaBibo KeC. J. TangY. HuY. P. LuZ. A. LiuM. L. ChenD. M. LiC. Morales MoralesP. X. ShenZ. WuD. XiaoM. PelizaeusF. CossioK. J. ZhuW. B. YanM. RichterZhiqing ZhangZ. NingKrisztian PetersM. N. AchasovZ. G. WangK. J. ZhuG. CibinettoH. Y. ZhangS. PacettiHaiwen LiuX. N. MaKe LiG. R. LiaoB. Q. WangG. Y. TangYunlong ZhangH. L. LiuD. BettoniG. F. ChenM. KuemmelJ. Y. ZhangJie ZhaoD. X. LinW. ShanJia XuAlexey ZhemchugovH. M. HuR. PolingDan WangM. KavatsyukJianping ZhengS. ZhuJin LiP. L. LiM. AlekseevI. UmanM. G. ZhaoR. P. GuoM. DestefanisB. X. ZhangP. LarinX. L. GaoC. DongS. SosioYao WangY. YangJoachim PetterssonJ. Q. ZhangS. L. NiuF. Y. LiX. Q. LiY. F. LongM. GrecoK. Y. LiuW. Ikegami AnderssonP. KieseS. L. OlsenR. A. BriereX. S. JiangO. CakirY. F. WangT. HussainX. Y. MaW. X. GongX. H. SunP. L. WangX. L. LuoK. BegzsurenF. BianchiHuanhuan LiuG. FeliciH. J. LiQ. L. XiuZongyuan WangQ. OuyangS. S. FangY. B. LiuH. B. Li

subject

Physics010308 nuclear & particles physicsElectron–positron annihilationAnalytical chemistryGeneral Physics and AstronomyLambda01 natural sciencesNear thresholdCross section (physics)Angular distribution0103 physical sciencesHigh Energy Physics::ExperimentBorn approximation010306 general physicsClearanceBar (unit)

description

The cross section of the e(+)e(-) -> Lambda(+)(c)(Lambda) over bar (-)(c) process is measured with unprecedented precision using data collected with the BESIII detector at root s = 4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross section near the Lambda(+)(c)(Lambda) over bar (-)(c) production threshold is cleared. At center-of-mass energies root s = 4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Lambda(c) polar angle distributions. From these, the.c electric over magnetic form-factor ratios (vertical bar G(E)/G(M)vertical bar) are measured for the first time. They are found to be 1.14 +/- 0.14 +/- 0.07 and 1.23 +/- 0.05 +/- 0.03, respectively, where the first uncertainties are statistical and the second are systematic.

https://doi.org/10.1103/physrevlett.120.132001