Experimental Review of <inline-formula><math display="inline"><semantics><mrow><mo mathvariant="bold">Λ</mo><mover accent="true"><mo mathvariant="bold">Λ</mo><mo stretchy="false">¯</mo></mover></mrow></semantics></math></inline-formula> Production

Abstract

Exclusive hyperon-antihyperon production provides a unique insight for understanding of the intrinsic dynamics when strangeness is involved. In this paper, we review the results of ΛΛ¯ production via different reactions from various experiments, e.g., via p¯p annihilation from the LEAR experiment PS185, via electron-positron annihilation using the energy scan method at the CLEO-c and BESIII experiments and the initial-state-radiation approach utilized at the BaBar experiment. The production cross section of ΛΛ¯ near the threshold is sensitive to QCD based prediction. Experimental high precision data for p¯p→Λ¯Λ close to the threshold region is obtained. The cross section of e+e−→ΛΛ¯ is measured from its production threshold to high energy. A non-zero cross section for e+e−→ΛΛ¯ near threshold is observed at BaBar and BESIII, which is in disagreement with the pQCD prediction. However, more precise data is needed to confirm this observation. Future experiments, utilizing p¯p reaction such as PANDA experiment or electron-positron annihilation such as the BESIII and BelleII experiments, are needed to extend the experimental data and to understand the ΛΛ¯ production.

Keywords

• Λ production%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> Λ<span style="text-decoration: overline">Λ</span> production
• threshold
• cross section