Strongly Resonating Bosons in Hot Nuclei

Abstract

When two heavy ions near the Fermi energy collide, a warm and low-density region can form in which fragments appear. This region is mainly dominated by proton (p) and alpha particles. In such an environment, the alphas interact with each other, and especially through strong resonances, form complex systems such as 8Be and 12C. Our experiments show that in the reactions 70(64)Zn(64Ni)+70(64)Zn(64Ni) at E/A=35 MeV/nucleon levels of 8Be appear around relative energies Eij=0.092 MeV, 3.03 MeV as well as above 10 MeV and 100 MeV. For the 3 alpha systems, multi resonance processes give rise to excited levels of 12C. In particular, the Hoyle state at 7.654 MeV excitation energy shows a decay component through the ground state of 8Be and also shows components where two different alpha couples are at relative energies consistent with the ground state of 8Be at the same time. A component where the three alpha relative energies are consistent with the ground state of 8Be (i.e., E12=E13=E23=0.092 MeV) is also observed at the 7.458 MeV excitation energy, which was suggested as an Efimov state.

arXiv comment8 pages, 5 figures

References in corpus (14)

• Efimov Physics: a review
• Ab initio calculation of the Hoyle state
• Observation of an Efimov spectrum in an atomic system
• Structure of ground and excited states of ${}^{12}$C
• Evidence for Triangular D_3h Symmetry in 12C
• Evidence for $\alpha$-particle condensation in nuclei from the Hoyle state deexcitation
• High precision probe of the fully sequential decay width of the Hoyle state in ${}^{12}$C
• The many facets of the (non relativistic) Nuclear Equation of State
• Decay and structure of the Hoyle state
• Decay Modes of the Hoyle State in ${}^{12}C$
• Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems
• Alpha Conjugate Neck Structures in the Collisions of 35 MeV/nucleon 40Ca with 40Ca
• Competition between fermions and bosons in nuclear matter at low densities and finite temperatures
• Triple α Resonances in the Decay of Hot Nuclear Systems *

Cited by in corpus (4)

• Evidence against the Efimov effect in ${}^{12}\mathrm{C}$ from spectroscopy and astrophysics
• A geometrical interpretation of the Thomas theorem and the Efimov States
• Triple α Resonances in the Decay of Hot Nuclear Systems *
• Temperature of the hot $\alpha$-source: a guidance to probe the Bose-Einstein condensation of $\alpha$ clusters in the heavy-ion collision