Proton induced Deuteron Breakup reaction studies at COSY

The present thesis is dedicated to the study of the pd Breakup re¬action. The study is part of a project, realized at the COSY storage ring, finalized to map pd breakup spin observables in a kinematical region where measurements are limited although strongly necessary to fix important constraints for investigating the role of the three-nucleon forces via the Chiral Perturbation Theory. In the first part of the work, I developed an analysis chain to determine whether a detection system based on Silicon Tracking Telescope, origi¬nally conceived to identify pd elastic events, was capable to identify the products of the pd Breakup reaction. This feasibility study has been successfully applied to an existing data sample taken at the COSY ring in February 2008, with a vertically polarized proton beam of 49.3 MeV kinetic energy impinging on a Deuterium cluster target. In a following phase, the identified pd Breakup events have been employed to tune an algorithm to measure the analysing power in pd Breakup reaction using the neutron asymmetries. This observable represents one of the probes to constrain Chiral Perturbation Theory. The analysis of the available data sample has allowed to outline the experimental condi¬tions required for an exhaustive investigation of the spin observables in pd breakup reaction. On the other side, the low statistics and the not optimal working conditions of the detection system made not possible to finalize the result on the existing data sample. At present the de¬veloped analysis is being exploited on a new sample of data acquired during 2011 beam-time. In parallel, I carried out a study of a new apparatus devoted to the pd Breakup investigation. In particular double spin asymmetries in pd Breakup offer a rich laboratory where to test Chiral Perturbation Theory. For accessing these observables, an experiment where both the proton beam and the deuterium target are polarized would be required. In addition a detection system providing a large aziniuthal and longitudinal phase-space coverage would be needed. For this reason, I implemented the analysis software, developed in the first stage of my work, for the characterization and the optimization of this dedicated detection system on the basis of Monte Carlo gen¬erated data. The results of the analysis served as a guidance for the detector design and have been included in a proposal[l| submitted and successfully reviewed from the PAC of COSY.