Details

Autor(en) / Beteiligte

• Ablikim, M.
• Achasov, M. N.
• Ahmed, S.
• Ai, X. C.
• Albayrak, O.
• Albrecht, M.
• Ambrose, D. J.
• Amoroso, A.
• An, F. F.
• An, Q.
• Bai, J. Z.
• Bakina, O.
• Baldini Ferroli, R.
• Ban, Y.
• Bennett, D. W.
• Bennett, J. V.
• Berger, N.
• Bertani, M.
• Bettoni, D.
• Bian, J. M.
• Bianchi, F.
• Boger, E.
• Boyko, I.
• Briere, R. A.
• Cai, H.
• Cai, X.
• Cakir, O.
• Calcaterra, A.
• Cao, G. F.
• Cetin, S. A.
• Chai, J.
• Chang, J. F.
• Chelkov, G.
• Chen, G.
• Chen, H. S.
• Chen, J. C.
• Chen, M. L.
• Chen, S.
• Chen, S. J.
• Chen, X.
• Chen, X. R.
• Chen, Y. B.
• Chu, X. K.
• Cibinetto, G.
• Dai, H. L.
• Dai, J. P.
• Dbeyssi, A.
• Dedovich, D.
• Deng, Z. Y.
• Denig, A.
• Denysenko, I.
• Destefanis, M.
• De Mori, F.
• Ding, Y.
• Dong, C.
• Dong, J.
• Dong, L. Y.
• Dong, M. Y.
• Dou, Z. L.
• Du, S. X.
• Duan, P. F.
• Fan, J. Z.
• Fang, J.
• Fang, S. S.
• Fang, X.
• Fang, Y.
• Farinelli, R.
• Fava, L.
• Fegan, S.
• Feldbauer, F.
• Felici, G.
• Feng, C. Q.
• Fioravanti, E.
• Fritsch, M.
• Fu, C. D.
• Gao, Q.
• Gao, X. L.
• Gao, Y.
• Gao, Z.
• Garzia, I.
• Goetzen, K.
• Gong, L.
• Gong, W. X.
• Gradl, W.
• Greco, M.
• Gu, M. H.
• Gu, Y. T.
• Guan, Y. H.
• Guo, A. Q.
• Guo, L. B.
• Guo, R. P.
• Guo, Y.
• Guo, Y. P.
• Haddadi, Z.
• Hafner, A.
• Han, S.
• Hao, X. Q.
• Harris, F. A.
• He, K. L.
• Heinsius, F. H.

Titel

Observation of a cross-section enhancement near mass threshold in e + e − → Λ Λ

Ist Teil von

• Physical review. D, 2018-02, Vol.97 (3), Article 032013

Ort / Verlag

United States: American Physical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The process e+e- → Λ Λ ¯ is studied using data samples at √s = 2.2324, 2.400, 2.800 and 3.080 GeV collected with the BESIII detector operating at the BEPCII collider. The Born cross section is measured at √s=2.2324 GeV, which is 1.0 MeV above the Λ Λ ¯ mass threshold, to be 305±$45_{-36}^{+66}$ pb, where the first uncertainty is statistical and the second systematic. The substantial cross section near threshold is significantly larger than that expected from theory, which predicts the cross section to vanish at threshold. The Born cross sections at √s=2.400, 2.800 and 3.080 GeV are measured and found to be consistent with previous experimental results, but with improved precision. Finally, the corresponding effective electromagnetic form factors of Λ are deduced.