Speaker
Description
Theory models predict a total of 44 cascade states below 2.5 GeV. Currently, there are only six Ξ states that have at least a three-star rating in the PDG, with the production mechanism of these states still remaining mostly elusive. The goal of the “Very Strange” project is to study the quasi-real photoproduction of cascades to search for missing and new states. The new data from Jefferson Lab would make it possible to measure for the first time the beam polarisation transfer and induced polarisation of the Ξ- baryon as a kinematical variable function. Additionally, cascade studies look promising as a tool to differentiate genuine quark states from hadronic molecules, for which the Ξ(1620) resonance is an interesting state to study as it is believed to be the doubly strange analogue to the Λ(1405), since we have the ability to measure the line shape in various decay branches with unprecedented precision. The study of cascades looks to be appealing from a theoretical perspective due to the symmetry from two medium-mass s-quarks. This work focuses on the analysis of CLAS12 data collected at Jefferson Lab to study the production mechanisms and decays of excited Ξ- states that are not well established, with the aim of determining branching ratios and extracting the quantum numbers of the new and missing Ξ states.
