Three-body bound states with zero-range interaction in the Bethe–Salpeter approach

Physics Letters B

J.H. Alvarenga Nogueira¹  E. Ydrefors¹  T. Frederico¹  V. Gigante²  V.A. Karmanov³ 

[1] Instituto Tecnológico de Aeronáutica, DCTA, 12228-900 São José dos Campos, Brazil;Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo, Brazil;Lebedev Physical Institute, Leninsky Prospekt 53, 119991 Moscow, Russia;

关键词: Bethe–Salpeter equation;    Light-front dynamics;    Zero-range interaction;    Relativistic three-body bound states;   

DOI  :  10.1016/j.physletb.2017.04.035

来源: DOAJ

【 摘 要 】

The Bethe–Salpeter equation for three bosons with zero-range interaction is solved for the first time. For comparison the light-front equation is also solved. The input is the two-body scattering length and the outputs are the three-body binding energies, Bethe–Salpeter amplitudes and light-front wave functions. Three different regimes are analyzed: (i) For weak enough two-body interaction the three-body system is unbound. (ii) For stronger two-body interaction a three-body bound state appears. It provides an interesting example of a deeply bound Borromean system. (iii) For even stronger two-body interaction this state becomes unphysical with a negative mass squared. However, another physical (excited) state appears, found previously in light-front calculations. The Bethe–Salpeter approach implicitly incorporates three-body forces of relativistic origin, which are attractive and increase the binding energy.

【 授权许可】

Unknown