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

TL;DR

This paper investigates the indirect production mechanisms of doubly charmed tetraquarks $T_{cc}$ at high-energy colliders using nonrelativistic QCD, predicting production rates and distributions at LHC and CEPC.

Contribution

It introduces a detailed analysis of $T_{cc}$ production via Higgs, Z, and W decays, including decay widths, branching ratios, and event predictions, highlighting the dominant sources at different colliders.

Findings

W+ decay produces the most $T_{cc}$ events at LHC.

Z0 decay dominates $T_{cc}$ production at CEPC.

Predicted annual events: $1.80\times10^5$ at LHC via W+ decay.

Abstract

The indirect production mechanisms of doubly charmed tetraquark $T_{cc}$ through three decay channels, Higgs$/Z^{0}\to \langle cc\rangle_{\bar{3}} +\bar{c}+\bar{c} \to T_{cc}^{\bar{q}\bar{q^{\prime}}} +\bar{c}+\bar{c} $ and $W^+\to \langle cc\rangle_{\bar{3}}+\bar{c}+\bar{s} \to T_{cc}^{\bar{q}\bar{q^{\prime}}} +\bar{c}+\bar{s} $, are analyzed within the framework of nonrelativistic QCD. The intermediate $\langle cc\rangle_{\bar{3}}$ diquark cluster in color antitriplet evolves into tetraquark components via the fragmentation process by trapping two light antiquarks ($\bar{q}$ and $\bar{q^{\prime}}$) 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 $1.80\times10^5$, nearly $2$ orders of magnitude larger than that by Higgs decays ($1.11\times10^{3}$) and $Z^{0}$ decays ($4.81\times10^3$) at LHC. However at CEPC, the largest contribution for the production of $T_{cc}$ is through $Z^{0}$ decays, about $1.63\times10^6$. There are only $4.79\times10^{-1}$ and $2.03\times10^{2}$ $T_{cc}$ events produced each year at CEPC through Higgs and $W^+$ decay, respectively.