Transverse polarization of $\Lambda$ hyperons from quasireal photoproduction on nuclei

Understand

The transverse polarization of $\Lambda$ hyperons was measured in inclusive quasireal photoproduction for various target nuclei ranging from hydrogen to xenon.

• The data were obtained by the HERMES experiment at HERA using the 27.6 GeV lepton beam and nuclear gas targets internal to the lepton storage ring.
• The polarization observed is positive for light target nuclei and is compatible with zero for krypton and xenon.