Article

Bottomonium in a Bethe-Salpeter-equation study

Physical review D: Particles and fields 09/2011; 84. DOI: 10.1103/PhysRevD.84.096014
Source: arXiv

ABSTRACT Using a well-established effective interaction in a rainbow-ladder truncation
model of QCD, we fix the remaining model parameter to the bottomonium
ground-state spectrum in a covariant Bethe-Salpeter equation approach and find
surprisingly good agreement with the available experimental data including the
2^{--} Upsilon(1D) state. Furthermore, we investigate the consequences of such
a fit for charmonium and light-quark ground states.

0 Bookmarks
 · 
125 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We determine the baryon octet and decuplet masses as well as their wave functions in a covariant three-body Faddeev approach. We work in an approximation where irreducible three-body forces are neglected. In the two-body interactions we take into account a well explored rainbow-ladder kernel as well as flavor dependent meson-exchange terms motivated from the underlying quark-gluon interaction. Without flavor dependent forces we find agreement with the experimental spectrum on the 5-10 percent level. Including the flavor dependent terms on an exploratory level delivers a Sigma/Lambda splitting with the correct sign although the magnitude is still too small.
    Physical Review D 08/2014; 90(9). · 4.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We study vacuum masses of charmonia and the charm-quark diffusion coefficient in the quark-gluon plasma based on the spectral representation for meson correlators. To calculate the correlators, we solve the quark gap equation and the inhomogeneous Bethe-Salpeter equation in the rainbow-ladder approximation. It is found that the ground-state masses of charmonia in the pseudoscalar, scalar, and vector channels can be well described. For $1.5\,T_c<T<3.0\,T_c$, the value of the diffusion coefficient $D$ is comparable with that obtained by lattice QCD and experiments: $3.4<2\pi TD<5.9$. Relating the diffusion coefficient with the ratio of shear viscosity to entropy density $\eta/s$ of the quark-gluon plasma, we obtain values in the range $0.09<\eta/s<0.16$.
    Physics Letters B 03/2014; 734. · 6.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We extend the calculation of relativistic bound-states of a fermion anti-fermion pair in the Bethe-Salpeter formalism to the case of total angular momentum $J=3$. Together with results for $J \le 2$ this allows for the investigation of Regge trajectories in this approach. We exemplify such a study for ground and excited states of light unflavored mesons as well as strange mesons within the rainbow-ladder approximation. For the $\rho$- and $\phi$-meson we find a linear Regge trajectory within numerical accuracy. Discrepancies with experiment in other channels highlight the need to go beyond rainbow-ladder and to consider effects such as state mixing and more sophisticated quark-antiquark interaction kernels.
    European Physical Journal A 06/2014; 50(8). · 2.42 Impact Factor

Preview

Download
0 Downloads
Available from