Semileptonic decays of the scalar tetraquark $Z_{bc;\overline{u}\overline{d}}^0$

Abstract

We study semileptonic decays of the scalar tetraquark $Z_{bc;\overline{u}\overline{d}}^0$ to final states $T_{bs;\overline{u}\overline{d}}^{-}{e}^{+}{\nu }_e$ and $T_{bs;\overline{u}\overline{d}}^{-}{\mu }^{+}{\nu }_{\mu }$ , which run through the weak transitions $c\to s{e}^{+}{\nu }_e$ and $c\to s{\mu }^{+}{\nu }_{\mu }$, respectively. To this end, we calculate the mass and coupling of the final-state scalar tetraquark $T_{bs;\overline{u}\overline{d}}^{-}$ by means of the QCD two-point sum rule method: these spectroscopic parameters are used in our following investigations. In calculations we take into account the vacuum expectation values of the quark, gluon, and mixed operators up to dimension ten. We use also three-point sum rules to evaluate the weak form factors $G_i(q^2)$ ($i=1,2$) that describe these decays. The sum rule predictions for $G_i(q^2)$ are employed to construct fit functions $F_i(q^2)$, which allow us to extrapolate the form factors to the whole region of kinematically accessible $q^2$. These functions are required to get partial widths of the semileptonic decays $\Gamma \left(Z_{bc}^0\to T{e}^{+}{\nu }_e\right)$ and $\Gamma \left(Z_{bc}^0\to T{\mu }^{+}{\nu }_{\mu }\right)$ by integrating corresponding differential rates. We analyze also the two-body nonleptonic decays $Z_{bc;\overline{u}\overline{d}}^0\to T_{bs;\overline{u}\overline{d}}^{-}{\pi }^{+}$ and $Z_{bc;\overline{u}\overline{d}}^0\to T_{bs;\overline{u}\overline{d}}^{-}{K}^{+}$, which are necessary to evaluate the full width of the $Z_{bc;\overline{u}\overline{d}}^0$. The obtained results for ${\Gamma }_{\mathrm{full}}=(3.18\pm 0.39)\times 10^{-11}\mathrm{MeV}$ and mean lifetime $20.7_{-2.3}^{+2.9}\mathrm{ps}$ of the tetraquark $Z_{bc;\overline{u}\overline{d}}^0$ can be used in experimental investigations of this exotic state.

10 Pages and 3 Figures

References in corpus (13)

• Discovery of doubly-charmed Xi_{cc} baryon implies a stable (b b ubar dbar) tetraquark
• Heavy-quark symmetry implies stable heavy tetraquark mesons $Q_i{Q}_j{\bar{q}}_k{\bar{q}}_l$
• Masses of tetraquarks with two heavy quarks in the relativistic quark model
• QCD sum rules study of $QQ-\bar{u}\bar{d}$ mesons
• Evidence for charm-bottom tetraquarks and the mass dependence of heavy-light tetraquark states from lattice QCD
• Exotic $QQ\bar{q}\bar{q}$, $QQ\bar{q}\bar{s}$ and $QQ\bar{s}\bar{s}$ states
• Discovery potential of stable and near-threshold doubly heavy tetraquarks at the LHC
• Dynamical study of $\mathbf{QQ}-\bar{\mathbf{u}}\bar{\mathbf{d}}$ mesons
• Production of doubly charmed tetraquarks with exotic color configurations in electron-positron collisions
• Weak decays of the axial-vector tetraquark $T_{bb;\bar{u}\bar{d}}^{-}$
• Exotic $bc\bar{q}\bar{q}$ four-quark states
• Open charm-bottom scalar tetraquarks and their strong decays
• Probing an axial-vector tetraquark $Z_s$ via its semileptonic decay $Z_s\to X(4274)\overline{l}{\nu }_l$

Cited by in corpus (12)

• Masses of doubly heavy tetraquarks $T_{Q{Q}^{\prime }}$ in a relativized quark model
• A lattice investigation of exotic tetraquark channels
• Doubly heavy tetraquarks in a chiral-diquark picture
• Exploring fully heavy scalar tetraquarks $QQ\overline{Q}\overline{Q}$
• Heavy exotic scalar meson $T_{bb;\bar{u}\bar{s}}^{-}$
• Semileptonic and nonleptonic decays of the axial-vector tetraquark $T_{bb;\overline{u}\overline{d}}^{-}$
• Masses and Magnetic Moments of Doubly Heavy Tetraquarks via Diffusion Monte Carlo Method
• A family of double-beauty tetraquarks: Axial-vector state $T_{bb;\bar{u}\bar{s}}^{-}$
• Double-heavy axial-vector tetraquark $T_{bc;\bar{u}\bar{d}}^0$
• Stable scalar tetraquark $T_{bb;\bar{u}\bar{d}}^{-}$
• Decay modes of the scalar exotic meson $T_{bs;\overline{u}\overline{d}}^{-}$
• Weak-decay searches for $Qs\bar{u}\bar{d}$ tetraquarks