Indirect production of doubly charmed tetraquarks $T_{cc}$ at high energy colliders

Abstract

The indirect production mechanisms of doubly charmed tetraquark $T_{cc}$ through three decay channels, Higgs$/Z^0\to ⟨cc{⟩}_{\bar{3}}+\bar{c}+\bar{c}\to T_{cc}^{\bar{q}\overline{q^{\prime }}}+\bar{c}+\bar{c}$ and $W^{+}\to ⟨cc{⟩}_{\bar{3}}+\bar{c}+\bar{s}\to T_{cc}^{\bar{q}\overline{q^{\prime }}}+\bar{c}+\bar{s}$, are analyzed within the framework of nonrelativistic QCD. The intermediate $⟨cc{⟩}_{\bar{3}}$ diquark cluster in color antitriplet evolves into tetraquark components via the fragmentation process by trapping two light antiquarks ($\bar{q}$ and $\overline{q^{\prime }}$) from the vacuum. After the considered doubly charmed tetraquark components are summed, including $T_{cc}^{\bar{u}\bar{u}}$, $T_{cc}^{\bar{u}\bar{d}}$, $T_{cc}^{\bar{d}\bar{d}}$, $T_{cc}^{\bar{u}\bar{s}}$, and $T_{cc}^{\bar{d}\bar{s}}$, the decay widths, branching ratios, and produced events each year for the production of $T_{cc}$ can be predicted at LHC and CEPC, respectively. The differential distributions and two main sources of theoretical uncertainty are also discussed. The results show that the produced events each year for $T_{cc}$ via $W^{+}$ decays is $1.80\times 10^5$, nearly $2$ orders of magnitude larger than that by Higgs decays ($1.11\times 10^3$) and $Z^0$ decays ($4.81\times 10^3$) at LHC. However at CEPC, the largest contribution for the production of $T_{cc}$ is through $Z^0$ decays, about $1.63\times 10^6$. There are only $4.79\times 10^{-1}$ and $2.03\times 10^2$ $T_{cc}$ events produced each year at CEPC through Higgs and $W^{+}$ decay, respectively.

Comments: 21 pages, 2 figures, 6 tables; Version to be published in PRD