Color flux-tube nature of the states <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mi>s</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>2900</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>T</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover accent="true"><mml:mi>s</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:mrow><mml:mi>a</mml:mi></mml:msubsup><mml:mo stretchy="false">(</mml:mo><mml:mn>2900</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math>
Jia Wei, Yi-Heng Wang, Chun-Sheng An, Chengrong Deng
Abstract
Inspired by the states ${T}_{cs0}(2900{)}^{0}$, ${T}_{cs1}(2900{)}^{0}$, ${T}_{c\overline{s}0}^{a}(2900{)}^{0}$, and ${T}_{c\overline{s}0}^{a}(2900{)}^{++}$ reported by the LHCb Collaboration, we carry out a systematical investigation on the properties of the ground and $P$-wave states $[cs][\overline{u}\overline{d}]$ and $[cu][\overline{s}\overline{d}]$ with various spin, isospin, or $U$ spin and color combinations in a multiquark color flux-tube model. Matching our results with the spin-parity and mass of the states ${T}_{cs0}(2900{)}^{0}$ and ${T}_{cs1}(2900{)}^{0}$, we can describe them as the compact states $[cs][\overline{u}\overline{d}]$ with $I({J}^{P})=1({0}^{+})$ and $0({1}^{\ensuremath{-}})$ in the model, respectively. The ground state ${T}_{cs0}(2900{)}^{0}$ is mainly made of strongly overlapped axial vector $[cs{]}_{{\overline{\mathbf{3}}}_{c}}$ and axial vector $[\overline{u}\overline{d}{]}_{{\mathbf{3}}_{c}}$. The $P$-wave state ${T}_{cs1}(2900{)}^{0}$ dominantly consists of a gradually separated scalar or axial vector $[cs{]}_{{\overline{\mathbf{3}}}_{c}}$ and a scalar $[\overline{u}\overline{d}{]}_{{\mathbf{3}}_{c}}$ in the shape of a dumbbell. Supposing the states ${T}_{c\overline{s}0}^{a}(2900{)}^{0}$ and ${T}_{c\overline{s}0}^{a}(2900{)}^{++}$ belong to the same isospin triplet, the mass of the state ${[[cu{]}_{{\overline{\mathbf{3}}}_{c}}[\overline{s}\overline{d}{]}_{{\mathbf{3}}_{c}}]}_{{\mathbf{1}}_{c}}$ with symmetrical $U$ spin and ${J}^{P}={0}^{+}$ is highly consistent with that of the states ${T}_{c\overline{s}0}^{a}(2900{)}^{0}$ and ${T}_{c\overline{s}0}^{a}(2900{)}^{++}$ in the model. After coupling two color configurations, the state $[cu][\overline{s}\overline{d}]$ is slightly lighter than the states ${T}_{c\overline{s}0}^{a}(2900{)}^{0}$ and ${T}_{c\overline{s}0}^{a}(2900{)}^{++}$. In addition, we also discuss the properties of other states in the model.