Electromagnetic radiation of baryons containing two heavy quarks

Abstract

The two heavy quarks in a baryon which contains two heavy quarks and a light one, can constitute a scalar or axial vector diquark. We study electromagnetic radiations of such baryons, (i) Ξ_{(bc)_1} -> Ξ_{(bc)_0}+γ, (ii) Ξ_{(bc)_1}^* -> Ξ_{(bc)_0}+γ, (iii) Ξ_{(bc)_0}^{**}(1/2, l=1) -> Ξ_{(bc)_0}+γ, (iv) Ξ_{(bc)_0}^{**}(3/2, l=1) -> Ξ_{(bc)_0}+γand (v) Ξ_{(bc)_0}^{**}(3/2, l=2) -> Ξ_{(bc)_0}+γ, where Ξ_{(bc)_{0(1)}}, Ξ^*_{(bc)_1} are S-wave bound states of a heavy scalar or axial vector diquark and a light quark, and Ξ_{(bc)_0}^{**}(l is bigger than 1) are P- or D-wave bound states of a heavy scalar diquark and a light quark. Analysis indicates that these processes can be attributed into two categories and the physical mechanisms which are responsible for them are completely distinct. Measurements can provide a good judgment for the diquark structure and better understanding of the physical picture.