Photoproduction of Λ(1405) → Σ ⁰π ⁰ at GlueX

Nilanga Wickramaarachchi

The Catholic University of America
Department of Physics 

Wed, March 23 , 2022 - 4:00 PM
JOIN ZOOM

Quantum Chromodynamics (QCD) is the fundamental theory explaining the strong force responsible for quarks and gluons. We can’t observe individual quarks but we see them in bound states called hadrons (baryons and mesons). In the experimental data we observe these states as resonances that peak in a certain invariant mass spectra composed from the particles that the resonance decays to. Hyperon spectroscopy provides us the opportunity to study baryons that contain strange quarks. The “line shape” of a resonance can be described as the mass or energy dependence of the resonance decay into a specific final state. For many resonances in hyperon spectroscopy the line shape can be modelled by a Breit-Wigner distribution. However, previous measurements of the line shape of Λ(1405) baryon indicated significant distortion from a BreitWigner form. The GlueX experiment at Jefferson Lab provides an excellent opportunity to study the Λ(1405) → Σ ⁰π ⁰ decay mode with a photon beam in the energy range 6.5–11.6 GeV incident on a liquid hydrogen target and a large acceptance electromagnetic calorimeter. Preliminary results will be presented which will be used to understand the Λ(1405) line shape in the future. 

 

If you have any questions about the Colloquium Series, would like to request disability accommodations  or would like to make a donation please contact the Physics Department, cua-physics@cua.edu or  call (202) 319-5315.