Measurement of Λ transverse polarization in e+e− collisions at $$ \sqrt{s} $$ = 3.68 − 3.71 GeV

Journal article

With data samples collected with the BESIII detector at seven energy points at s = 3.68 − 3.71 GeV, corresponding to an integrated luminosity of 333 pb−1, we present a study of the Λ transverse polarization in the e + e − → Λ Λ ¯ reaction. The significance of polarization by combining the seven energy points is found to be 2.6σ including the systematic uncertainty, which implies a non-zero phase between the transition amplitudes of the Λ Λ ¯ helicity states. The modulus ratio and the relative phase of EM-psionic form factors combined with all energy points are measured to be R Ψ = 0.71−0.10+0.10 ± 0.03 and ∆ΦΨ = 23−8.0+8.8 ± 1.6°, where the first uncertainties are statistical and the second systematic. [Figure not available: see fulltext.

Authors: Ablikim, M; Achasov, MN; Adlarson, P; Aliberti, R; Amoroso, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Journal of High Energy Physics
• Volume: 2023
• Issue: 10
• Pages: 81
• Publication date: 2023-10-13
• DOI: 10.1007/jhep10(2023)081
• EISSN: 1029-8479
• ISSN: 1126-6708
• Language: English