The mass spectrum and wave functions of the B_c system

The spectrum and relativistic wave functions of B_c system are investigated via solving the complete Salpeter equation. Emphases are put on the study of the partial waves of each J^P state. Our study shows that there are three categories of J^P states. The first category contains 0⁻ and 0⁺ states, which are ¹S₀ dominant state with a small amount of P wave and ³P₀ dominant state with a small amount of S wave, respectively. The second category includes the natural parity states, such as 1⁻, 2⁺, 3⁻, etc. Taking the 1⁻ state as an example, we study it in two cases. One is the ³S₁ dominant state with a small amount of P and D waves, and the other is the ³D₁ dominant state but contains a large amount of S and P wave components. The third category includes the unnatural parity states, such as 1⁺, 2⁻, 3⁺, etc. For the 1⁺ spectrum, the states are grouped into pairs with different radial quantum numbers. Each pair contains two ¹P₁−³P₁ mixing states, and the corresponding mixing angles are calculated by using the relativistic wave functions.