Electroweak properties of octet baryons in a light-cone quark-diquark model

We study the electroweak properties of ground state octet baryons in a relativistic quark-spectator-diquark model, with a light-front formalism applied to take relativistic effects into account. Our model provides a consistent picture of the electroweak properties of the ground state octet baryons in the low momentum transfer region. The Melosh-Wigner rotation is applied as the transformation relation between spinors in the instant form and front form. Numerical results are presented for the magnetic moments, weak transition charges, and Sachs form factors. Our results are in good agreement with experimental measurements and other theoretical results.

Figure 1

Electric (a) and magnetic (b) form factors of proton calculated with different wave functions and parameters. Data are from Ref. [41].

Figure 2

Electric (a) and magnetic (b) form factors of neutron calculated with different wave functions and parameters. Data are from Ref. [42].

Figure 3

Electric form factor of the octet baryons calculated with different wave functions and parameters, compared with lattice results in Ref. [4].

Figure 4

Magnetic form factor of the octet baryons calculated with different wave functions and parameters, compared with lattice results in Ref. [4].

Figure 5

The $u$ and $d$ contributions to the proton form factors (multiplied by $Q^4$). The $d$ contributions are multiplied by a factor for better comparison. The normalization factor ${\kappa }_q$ is given by ${\kappa }_q=F_2^q\left(0\right)$. Experimental data are from Ref. [34].