SEMINÁRIO DO GRUPO DE HÁDRONS E FÍSICA TEÓRICA - FEP
“Efimov physics in unbalanced three-body systems”
Dr. Mahdi Shalchi, IFT-UNESP
Dia: 02 de maio, terça-feira, às 17h.
Local: Ed. Principal, Ala 2, sala 335, IFUSP.
Resumo:
Three body unbalanced system in a general model ααβ when is studied within a three-body Faddeev formalism in low energies and for two different situations: 1- For A > 1, the behavior of an Efimov excited state of three body halo nuclei 20C in BIFUSP 2. a general neutron-neutron-core system is investigated by considering zero-ranged as well as finite-ranged separable Yamaguchi potential. By increasing the n−18C binding energy, it was verified that the excited state of 20C goes to a virtual state. It is confirmed that the analytical structure of the unitary cut is not affected by the range of the potential or mass asymmetry of the three-body system. Also, the low-energy properties of the elastic s−wave scattering for the n−19C are studied near the critical condition for the occurrence of an excited Efimov state in n − n−18C. We obtain some universal characteristics given by the pole-position of and effective-range parameters. 2- for A <<1, we show that the discrete Efimov scaling factor, well-known in the low-energy spectrum of a three-body system near the unitary limit, can be well identified in the elastic cross-section of the collision of a heavy atomic specie H when colliding with a shallow molecule formed by the heavy-light bound system (HL). In view of the fact that the scaling behavior is better verified for large imbalanced masses with , our present results can be quite relevant for the going-on experimental efforts to study Efimov physics in cold-atom laboratories.
