English

Free energy and criticality in the nucleon pair breaking process

Nuclear Experiment 2007-05-23 v2

Abstract

Experimental level densities for 171,172Yb, 166,167Er, 161,162Dy, and 148,149Sm are analyzed within the microcanonical ensemble. In the even isotopes at excitation energies E < 2 MeV, the Helmholtz free energy F signals the transition from zero to two quasiparticles. For E > 2 MeV, the odd and even isotopes reveal a surprisingly constant F at a critical temperature Tc of appr. 0.5 MeV, indicating the continuous melting of nucleon Cooper pairs as function of excitation energy.

Keywords

Cite

@article{arxiv.nucl-ex/0209013,
  title  = {Free energy and criticality in the nucleon pair breaking process},
  author = {M. Guttormsen and R. Chankova and M. Hjorth-Jensen and J. Rekstad and S. Siem and A. Schiller and D. J. Dean},
  journal= {arXiv preprint arXiv:nucl-ex/0209013},
  year   = {2007}
}

Comments

11 pages, including 6 figures, to be published in Physical Review C