The concept of pseudospin is often introduced to reveal the dynamical nature of quantum systems. The pseudospin symmetry (PSS) was found in atomic nuclei in 1960s and revealed as a relativistic symmetry connected with the small component of the Dirac spinor in 1990s. The PSS in single particle bound states has been studied extensively. By examining the zeros of Jost functions corresponding to the small components of Dirac wave functions and phase shifts of continuum states, researchers from the nuclear theory group at the Institute of Theoretical Physics have shown that the PSS in single particle resonant states in nuclei is conserved when the attractive scalar and repulsive vector potentials have the same magnitude but opposite sign. The exact conservation and the breaking of the PSS are illustrated for single particle resonances in spherical square-well and Woods-Saxon potentials. This work was published in Physical Review Letters 109 (2012) 072501.

Link：http://dx.doi.org/10.1103/PhysRevLett.109.072501

Contact: Prof. Zhou Shan-Gui (sgzhou@itp.ac.cn)