双重味重子的理想混合角

Magic Mixing Angles for Doubly Heavy Baryons

本工作研究了双重味重子的理想混合角。理想混合角是将^(2S+1)(lλ)_(J)态转换为具有确定重夸克对称性的态时所对应的旋转角度。在标准的ρ-λ图像下,求得了L_(ρ)= 0情形时重夸克对称性的态(J, jℓ) 和(J,s_(q)+j_(ρ))=(J,{^(4)l_(λ)/^(2)l_(λ)})态之间的理想混合角,其中jℓ=l_(λ)+s_(q)m,s_(ρ)=s _(Q1)+s _(Q2)和j_(ρ)=s_(ρ)+L_(ρ)。本工作指出当研究双重味重子的衰变性质时,需要采用(1S1p)1/2^(−)和(1S1p)3/2^(-)等理想混合态。

We study the so-called magic mixing angles for doubly heavy baryons.Defining that a magic mixing angle rotates states with definite^(2S+1)(lλ)_(J) to make them heavy-quark symmetric states,we derive the magic mixing angle only in the case L_(ρ)= 0 between the heavy quark symmetric states with quantum numbers(J, jℓ) and the states with(J,s_(q)+j_(ρ))=(J,{^(4)l_(λ)/^(2)l_(λ)}) for a doubly heavy baryon in the standard ρ-λ configuration,where jℓ=l_(λ)+s_(q),s_(ρ)=s_(Q1)+s_(Q2),and j_(ρ)=s_(ρ)+L_(ρ).We point out that when we calculate decays of doubly heavy baryons,we need to consider decays of magically mixed states,such as(1S1p)1/2^(−),(1S1p)3/2^(-) and so on.