Observation of e+e? → pppˉnˉπ? + c.c.*

作者：Ablikim M.; Achasov M.N.; Adlarson P.; Albrecht M.; Aliberti R.; Amoroso A.; An M.R.; An Q.; Bai X.H.; Bai Y.; Bakina O.; Baldini Ferroli R.; Balossino I.; Ban Y.; Batozskaya V.; Becker D.; Begzsuren K.; Berger N.; Bertani M.; Bettoni D.; Bianchi F.; Bloms J.; Bortone A.; Boyko I.; Briere R.A.; Brueggemann A.; Cai H.; Cai X.; Calcaterra A.; Cao G.F.; Cao N.; Cetin S.A.; Chang J.F.; Chang W.L.; Chelkov G.; Chen C.; Chen C.; Chen G.; Chen H.S.; Chen M.L.; Chen S.J.; Chen S.M.; Chen T.; Chen X.R.

来源：Chinese Physics C, 2023, 47(4): 043001.

DOI：10.1088/1674-1137/acb6eb

• cross section measurement
• di-baryon states
• hexaquark
• Multi-baryon channel

Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESIII detector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb?1 , the process e+e? → pppˉnˉ π? + 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 pˉnˉ and ppπ? invariant mass spectra are consistent with phase space distributions, indicating that no hexaquark or di-baryon state is observed. ? 2023 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

• 出版日期2023