Systematic Study of Three-Nucleon Systems Dynamics in the Cross Section of the Deuteron–Proton Breakup Reaction

B Kłos,W Parol,B Jamróz,I Skwira-Chalot,A Magiera,I Ciepał,G Khatri,S Kistryn,E Stephan,A Kozela

doi:10.1007/s00601-014-0891-6

Abstract

An experiment to investigate the 1H(d, pp)n breakup reaction using a deuteron beam of 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY–Julich. The main goal was the detailed study of various aspects of few-nucleon dynamics in the medium energy region, with particular emphasis on relativistic effects and their interplay with three nucleon forces. These effects become more important with increasing available energy in the three nucleon system. Therefore the investigations at high energies are crucial to understand their nature. The almost 4π geometry of the WASA detector gives an unique possibility to study various aspects of dynamics of processes in the three-nucleon reaction. Preliminary results obtained using the WASA detector are presented.

Highlights

Observables of deuteron–proton breakup reaction can be calculated using modern realistic nucleon–nucleon (N N ) interactions, combined with a suitable model of 3N forces [1]
The dynamics is treated within the Chiral Perturbation Theory (ChPT), so far at the next-to-next-toleading order with all relevant N N and 3N contributions taken into account [4]
The above listed calculations including different ingredients of nucleon–nucleon dynamics like the three nucleon force (3NF), the long-range Coulomb interaction or relativistic effects, predict their influence to reveal with different strength at different parts of the phase space

Summary

Introduction

Observables of deuteron–proton breakup reaction can be calculated using modern realistic nucleon–nucleon (N N ) interactions, combined with a suitable model of 3N forces [1]. We proposed the measurement of differential cross section of the 1 H (d, pp)n breakup reaction at energies of 340, 380 and 400 MeV. The investigations at this energy range will enable to study the evolution of the relativistic and 3NF effects. This will put strong constraints on the theoretical calculations and will allow to improve the quality of the existing few-nucleon potential models. In this energy range only very scarce data for the breakup observables exist

Experiment

Findings

Data Analysis