First Study of Reaction Ξ0n → Ξ -p Using Ξ0-Nucleus Scattering at an Electron-Positron Collider

Ablikim, M.; Achasov, M. N.; Adlarson, P.; Aliberti, R.; Amoroso, A.; An, M. R.; An, Q.; Bai, Y.; Bakina, O.; Balossino, I.; Ban, Y.; Batozskaya, V.; Begzsuren, K.; Berger, N.; Berlowski, M.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bianco, E.; 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, T. T.; Chang, W. L.; Che, G. R.; Chelkov, G.; Chen, C.; Chen, Chao; Chen, G.; Chen, H. S.

Science Citation Index Expanded

摘要

Using (1.0087 & PLUSMN; 0.0044) x 1010 J=iy events collected with the BESIII detector at the BEPCII storage ring, the process E0n & RARR; E-p is studied, where the E0 baryon is produced in the process J=iy & RARR; E0E over bar 0 and the neutron is a component of the 9Be, 12C, and 197Au nuclei in the beam pipe. A clear signal is observed with a statistical significance of 7.1u. The cross section of the reaction E0 + 9Be & RARR; E- + p + 8Be is determined to be u(E0 + 9Be & RARR; E- + p + 8Be) = (22.1 & PLUSMN; 5.3stat & PLUSMN; 4.5sys) mb at the E0 momentum of 0.818 GeV=c, where the first uncertainty is statistical and the second is systematic. No significant H-dibaryon signal is observed in the E-p final state. This is the first study of hyperon-nucleon interactions in electron-positron collisions and opens up a new direction for such research.

关键词

NUCLEAR-PHYSICS CROSS-SECTIONS STRANGENESS S H-DIBARYON WEAK DECAY SEARCH XI