论文标题
在轻夸克模型中对1s和2s状态重介子的混合效果
Mixing effects on 1S and 2S state heavy mesons in the light-front quark model
论文作者
论文摘要
在轻夸克模型中分析了$ 1S $和$ 2S $ State重型伪卡（$ p $）和矢量（$ v $）的质谱和波浪函数。在我们对质谱和波函数分析中采用的重要经验约束是实验性质量差异关系，$Δm_p>Δm_v$，其中$Δm_{p（v）} = m^{2S} _ {2S} _ {p（p（v）} - m^m^{1S} _ {1S} _ {p（v） $ f_ {1s}> f_ {2s} $，$ 1S $和$ 2S $ MESON状态。我们在我们对哈密顿量的差异计算中保持了$ 1S $和$ 2S $状态的试验波函数的正交性，并用库仑和限制潜力限制潜力，并以重型和重量的$ p $和$ p $和$ v $ Meson的性质处理高精细的相互作用，这是由于重型Quark对称性的性质。认识到，如果不混合$ 1s $和$ 2S $状态，就无法满足经验约束，我们发现混合角$θ$的下限在$ 1S $和$ 2S $介于$θ_c= {\ rm cot}^{\ rm cot}^{ - 1}（2 \ sqrt}（2 \ sqrt {6} $} $和cimprimimin将角度混合在$ 12^\ circ $上，以覆盖重夸克的魅力和底部风味。发现混合效果对$ 2S $ State Mesons比$ 1S $ State Mesons更为重要。计算了$ 1S $和$ 2S $州介子的属性，包括质谱，衰减常数，扭曲2分布振幅和电磁形式。发现我们的结果与可用数据和晶格模拟符合良好的一致性。特别是，$ 2S $ state pseudoscalar $ d_s $ meson预计将质量为$ 2600 $ MEV，它非常接近新发现的新发现的$ d_ {s0}（2590）^+$ $ $梅森。这支持将观察到的状态解释为$ d^+_ s $梅森的径向激发。
The mass spectra and wave functions of both $1S$ and $2S$ state heavy pseudoscalar ($P$) and vector ($V$) mesons are analyzed within the light-front quark model. Important empirical constraints employed in our analysis of the mass spectra and wave functions are the experimental mass-gap relation, $ΔM_P > ΔM_V$, where $ΔM_{P(V)}=M^{2S}_{P(V)}-M^{1S}_{P(V)}$ and the hierarchy of the decay constants, $f_{1S}>f_{2S}$, between $1S$ and $2S$ meson states. We maintain the orthogonality of the trial wave functions of the $1S$ and $2S$ states in our variational calculation of the Hamiltonian with the Coulomb plus confining potentials and treat the hyperfine interaction perturbatively for the heavy-heavy and heavy-light $P$ and $V$ mesons due to the nature of the heavy quark symmetry. Realizing that the empirical constraints cannot be satisfied without mixing of the $1S$ and $2S$ states, we find the lower bound of the mixing angle $θ$ between $1S$ and $2S$ states as $θ_c = {\rm cot}^{-1}(2\sqrt{6})/2\simeq 6^{\circ}$ and obtain the optimum value of the mixing angle around $12^\circ$ to cover both the charm and bottom flavors of the heavy quark. The mixing effects are found to be more significant to the $2S$ state mesons than to the $1S$ state mesons. The properties of $1S$ and $2S$ state mesons including the mass spectra, decay constants, twist-2 distribution amplitudes, and electromagnetic form factors are computed. Our results are found to be in a good agreement with the available data and lattice simulations. In particular, the $2S$ state pseudoscalar $D_s$ meson is predicted to have a mass of $2600$ MeV, which is very close to the mass of the newly discovered $D_{s0}(2590)^+$ meson by the LHCb Collaboration. This supports the interpretation of the observed state as a radial excitation of the $D^+_s$ meson.
