First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Area of Science:

• Nuclear Physics
• Particle Physics

Background:

• Semi-inclusive deep-inelastic scattering (SIDIS) probes the structure of nucleons and nuclei.
• Understanding hyperon production in nuclear matter is crucial for nuclear structure studies.

Purpose of the Study:

• To measure Lambda hyperon production in SIDIS off various nuclear targets.
• To investigate the energy fraction (z) and fragmentation region dependence of Lambda multiplicity ratios and transverse momentum broadening.

Main Methods:

• Utilized the CLAS detector and a 5.014 GeV electron beam.
• Analyzed data from deuterium, carbon, iron, and lead targets.

Main Results:

• Observed a strong suppression of Lambda multiplicity ratio at high z and enhancement at low z.
• Measured transverse momentum broadening significantly larger than for light mesons.
• Results suggest strong interaction of propagating entities with the nuclear medium, possibly involving diquarks.

Conclusions:

• The findings provide insights into nucleon structure and strange baryon propagation in nuclear matter.
• The observed phenomena are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model.
• These results may initiate new avenues for studying nucleon structure and strange baryons.