@article{9a560f299f004fbbaadf83e0cb4fac49,
title = "Observation of a near-threshold enhancement in the Λ Λ ¯ mass spectrum from e+e- →φ Λ Λ ¯ at s from 3.51 to 4.60 GeV",
abstract = "The process e+e-→φΛΛ¯ is studied using data samples collected with the BESIII detector at the BEPCII Collider at center of mass energies s ranging from 3.51 GeV to 4.60 GeV. An enhancement is observed near the threshold of ΛΛ¯. The lineshape of this enhancement is studied in different approaches, including fit with a Breit-Wigner function or a reversed exponential function. The Breit-Wigner function has a mass of (2262±4±28) MeV/c2 and a width of (72±5±43) MeV, where the quoted uncertainties are statistical and systematic, respectively. The rising rate of the reversed exponential function is measured as 33±11±6 MeV/c2. For the ΛΛ¯ system, the JPC quantum numbers of 0-+ and 0++ are rejected, while other JPC hypotheses are possible, according to the helicity-angle study. The energy-dependent cross section of the e+e-→φΛΛ¯ process is measured for the first time in this energy region, and contributions from excited ψ states and vector charmoniumlike Y-states are investigated.",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and P. Adlarson and S. Ahmed and M. Albrecht and R. Aliberti and A. Amoroso and An, {M. R.} and Q. An and Bai, {X. H.} and Y. Bai and O. Bakina and {Baldini Ferroli}, R. and I. Balossino and Y. Ban and K. Begzsuren and N. Berger and M. Bertani and D. Bettoni and F. Bianchi and J. Bloms and A. Bortone and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and A. Calcaterra and Cao, {G. F.} and N. Cao and Cetin, {S. A.} and Chang, {J. F.} and Chang, {W. L.} and G. Chelkov and Chen, {D. Y.} and G. Chen and Chen, {H. S.} and Chen, {M. L.} and Chen, {S. J.} and Chen, {X. R.} and Chen, {Y. B.} and Chen, {Z. J.} and Cheng, {W. S.} and G. Cibinetto and F. Cossio and Cui, {X. F.} and Dai, {H. L.} and Dai, {X. C.} and A. Dbeyssi and Muchnoi, {N. Yu} and Nikolaev, {I. B.}",
note = "Funding Information: The BESIII collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by National Key Research and Development Program of China under Contracts No. 2020YFA0406300 and No. 2020YFA0406400; National Natural Science Foundation of China (NSFC) under Contracts No. 11625523, No. 11635010, No. 11735014, No. 11822506, No. 11835012, No. 11935015, No. 11935016, No. 11935018, and No. 11961141012; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts No. U1732263 and No. U1832207; CAS Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003 and No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; Institute of Nuclear and Particle Physics, Astronomy and Cosmology (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; ERC 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 No. 443159800, Collaborative Research Center CRC 1044, FOR 2359, FOR 2359, GRK 214; Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology fund; Olle 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 No. DH140054 and No. DH160214; The Swedish Research Council; U.S. Department of Energy under Contracts No. DE-FG02-05ER41374 and No. DE-SC-0012069. Publisher Copyright: {\textcopyright} 2021 authors. Published by the American Physical Society. Funded by SCOAP3.",
year = "2021",
month = sep,
day = "1",
doi = "10.1103/PhysRevD.104.052006",
language = "English",
volume = "104",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "AMER PHYSICAL SOC",
number = "5",
}